Rodrigues Starling
Encyclopedia
The Rodrigues Starling (Necropsar rodericanus), alternatively spelled Rodriguez Starling, is an extinct and quite enigmatic songbird
species
. It is the only valid species in genus
Necropsar, and provisionally assigned to the starling
family
(Sturnidae). This bird used to inhabit Rodrigues
in the Mascarenes and at least one of its offshore islet
s. The record of its erstwhile existence is limited to an old travel report and a few handfuls of subfossil bones.
In 1726 or shortly thereafter, the French naval officer Julien Tafforet of the La Ressource described his encounters with the bird on an offshore islet in the Relation d'île Rodrigue, which documented his 9-month stay in 1725. In 1874, Reverend Henry Horrocks Slater, a naturalist
of the British
Transit of Venus
expedition, found subfossil
bones of a starling-like songbird on Rodrigues proper, as had magistrate
George Jenner shortly before. These are generally assumed to belong to the bird Tafforet wrote about. Some additional bones were found in 1974. Together, they represent most of the skeleton, except for the spine
, pelvis
and the small bones, and are mainly in the Cambridge Museum. The IUCN regards the Rodrigues Starling as a valid species, because Tafforet's report and the bones provide compelling evidence that it existed.
N. rodericanus was frequently confused with a supposedly related but smaller species "N. leguati", described with specimen D.1792, a skin in the World Museum Liverpool
, as holotype
. This was also called "White Mascarene Starling" and variously considered a distinct parapatric or allopatric species, an immature, a colour morph or a female. It led some to believe that the Rodrigues Starling became extinct only about 1830, when the Liverpool specimen was collected. D.1792, however, was eventually identified as an albinistic individual of the Martinique Trembler (Cinclocerthia gutturalis).
. This would imply a total length of about 25–30 cm, and a weight of perhaps 90-130 g. Judging from the bones, the bird was about 10% smaller than the Bourbon Crested Starling
(Fregilupus varius), its presumed closest relative. Consequently, its length would have been about 25–28 cm and its weight perhaps 100-120 g when adult.
Its skeleton
largely agreed with F. varius in proportions, but differed in some details. The skull
was shaped somewhat differently, being longer (about 29 mm long from the occipital condyle
), narrower (21–22 mm), with the eyes set slightly lower, the upper rims of the eye sockets being some 8 mm apart. The interorbital septum was more delicate, with a larger hole in its center. The bill was about 36–39 mm long, less curved than in F. varius and proportionally a bit deeper, and seems to have had larger nostril
s, with the nostril openings in the bone 12–13 mm in length. The mandible
was about 52–60 mm long and 4–5 mm deep proximally. Its ulna
was somewhat shorter by comparison – measuring 37–40 mm versus 32–35 mm for the humerus
– and the keel on its sternum
was a bit lower, but its power of flight was not reduced. It had strong quill knobs on the ulna, indicating the secondary remiges were well-developed. One coracoid measured 27.5 mm in length, and one carpometacarpus
was 22.5 mm long. The leg and feet had the same proportions in both; in N. rodericanus the femur
measured around 33 mm, the tibiotarsus
52–59 mm, and the tarsometatarsus
36–41 mm.
The head and body plumage was white; tail and wings were partially black. Presumably, this included the flight feather
s, which are generally rich in eumelanin polymer
s that make the feather more robust. The wing- and tail-tips are, for example, even black in the Bali Myna (Leucopsar rothschildi), a starling
with otherwise entirely white plumage. It is not known whether the non-black (presumably white) part of the wings was a patch or wing-stripe, or simply the wing coverts or fringes or one vane
, as is commonly seen in birds in general. Reconstructions tend to show the tail with black tips and lighter feather bases. But while this is more likely than white-ended black rectrices, these too are seen in some birds and thus the tail pattern is essentially conjectural; it might just as well have had white fringes or vanes for example. The beak
, as well as the feet, were reported as yellow by Tafforet.
Tafforet makes no mention of marked sexual dimorphism
, or of a pronouncedly different juvenile plumage. His 9-month visit is likely to have encompassed at least part of the breeding season (but see below), and if so almost certainly a time where postbreeding moult
took place and when immature birds were around. Thus it may very well be that outward sexual and age differences were subdued or absent in N. rodericanus. The Bourbon Crested Starling had no pronounced sexual dichromatism either, but immature birds had a buff
y tinge. The beak of its adult females was about one-tenth shorter than in males; it may be that this was due to niche partitioning to better utilize the limited resources of its island home (see also Huia
). Too few skull remains of N. rodericanus have been found to date to assess whether it was similarly dimorphic. Among its limb bones – of which a larger number is known – the smallest do in fact measure 10% less than the largest.
The vocalizations are described by Tafforet as "a marvellous twitter [of] many and altogether different and all very joyful [calls]".
in 1879. According to Günther and Newton, the Rodrigues bird was closely related to the Bourbon Crested Starling
(Fregilupus varius). Several authors have intimated that they would rather have placed the species in Fregilupus, but none seem to have actually done so. Even though James Greenway
listed N. rodericanus as a junior synonym of F. varius, his description indicates that this was an inadvertent error. The 1974 bones allowed for a more thorough assessment, verifying that the Rodrigues bird is appropriately placed in the monotypic
genus
Necropsar, established by Slater in 1879. In 1900, believing Necropsar to be a mis-spelling, G. E. Shelley
"corrected" it to Necrospa and attributed it – erroneously – to Philip Sclater
. He also gave the authors of the species name as Günther and Newton, but their original text assigns authorship to Slater.
Masauyi Hachisuka, believing the carnivorous habits described by Tafforet to be unlikely for a starling and the lack of a crest suggesting against a close relationship with Fregilupus. He was reminded of corvids by the black-and-white plumage, and assumed the bird seen in 1725 was some sort of "chough
". These at his time were often still held to include the White-winged Chough
(Corcorax melanorhamphos) – which is actually not a corvid – and the "ground choughs" (Podoces). Still, Hachisuka believed Günther's and Newton's assessment regarding the bones to be accurate, only that according to him Tafforet's record could not have pertained to that bird. Thus, in 1937 he described the hypothetical "chough" as Testudophaga bicolor ("Bi-coloured Chough"). Hachisuka's assumptions are generally disregarded today for a number of reasons (see below).
; the affiliations of N. rodericanus, presumably but not certainly closely related to it, have been open to more dispute. Mid-20th century studies found some similarities between the Bourbon Crested Starling and the Prionopidae (helmetshrikes and woodshrikes). These are in the fairly basal songbird superfamily Corvoidea, and thus among the Passeri not at all closely related to starlings, which are more advanced songbirds in superfamily Muscicapoidea of the infraorder Passerida
. The Necropsar bones, while indeed reminiscent of Fregilupus (and the Prionopidae), remind much more of a starling's though.
In recent times, several songbirds of the Madagascar
region, whose relationships were believed to have been resolved, were instead found to be part of the vanga
s (Vangidae) or the as of 2009 unnamed "Malagasy warbler
s". These have both undergone spectacular adaptive radiation
s and might conceivably have evolved an insular starling-like form. Phylogenetically, an affiliation between the "Mascarene starlings" and either of the two Malagasy radiations – or the Prionopidae, for that matter – cannot be discounted as yet, in particular as no detailed comparisons seem to have ever been made.
Biogeographically, the Mascarenes avifauna
has either affiliations with birds from Madagascar and Africa
, or with South Asia
n lineages. The latter, however, is more common in older endemics, such as the dodos (Raphinae). While an African origin of the "Mascarene starlings" is thus more likely than a South Asian one, even this does not help much to narrow their relationships, as all possible relatives are native to Africa, and in case of the Sturnidae and Prionopidae also to South Asia.
As regards plumage, the White Helmetshrike
(Prionops plumatus) bears an uncanny resemblance to an imagined "hybrid" between the two "Mascarene starlings", with an overall coloration recalling Tafforet's description and a crest like F. varius. Among the vangas, species of Artamella, Falculea, Leptopterus and Vanga
have a similar coloration. But while most of the Afro-Asiatic lineage of starlings are either brownish-grey or have dark metallic hues, there are some light-bodied black-winged species found among them too, e.g. in the genera Creatophora, Speculipastor and Sturnia
. Consequently, the striking color pattern of Tafforet's birds is of little use in determining their relationships (except perhaps by suggesting against a close relationship to the "Malagasy warblers", which are predominantly greenish).
Anatomy
is quite characteristically autapomorphic among Passeriformes in general, but a few phylogenetic patterns can be discerned. Naturally, only Fregilupus varius can be studied in detail today. What can be said is that this species' overall myology
and osteology
and pterylosis is altogether passeriform. Pterylosis is no reliable trait to discern more detailed relationships, and in fact the Bourbon Crested Starling in this regard resembled a – clearly not very closely related – sickletail bird of paradise
(Cicinnurus) more than either the White-headed Vanga, the basal sturnid Aplonis tabuensis (Polynesian Starling), or the more advanced European Starling
(Sturnus vulgaris). The wing myology of passerine birds is rather uniform; compared to the three other taxa F. varius is fairly autapomorphic and does not agree consistently either with the starlings or the vanga. The pelvis and leg muscles of F. varius are even more strongly autapomorphic versus the comparison taxa, otherwise agreeing more with starlings than with Artamella. Its foot and toe muscles are notably more similar to starlings, at least where no different perching styles have obscured any phylogenetic pattern.
Fregilupus varius seems to have some synapomorphies with the more advanced Passerida
– Muscicapoidea and Passeroidea. Its tenth (outermost) primary remex is quite reduced for example. This feature is characteristically found in Passerida, but varies in extent, with the basal lineages have little reduction in length, and many nine-primaried oscine
s of the Passeroidea having lost that feather altogether. The pattern of scales on its feet also indicates a position among the Passerida at least. But these traits cannot be known for the Rodrigues bird of course. However, as F. varius, Muscicapoidea and Passeroidea have an apparently apomorphic divided fossa tricipitalis of the proximal humerus head. This serves as attachment point for the triceps brachii muscle
. In basal Passeri as well as Sylvioidea
(which are basal Passerida), there is only one fossa or at most a small second one. In Muscicapoidea and Passeroidea, there always seems to be a second fossa of some size present dorsal of the first. The humerus of Necropsar was said to "differ nowise" from that of Fregilupus or advanced starlings, and in the drawings of the fossils, the double fossa is visible. Judging from the anatomical studies, F. varius – and presumably also N. rodericanus – were probably not basal Passeri and quite likely belonged to the Muscicapoidea, and may indeed have been true starlings.
That Tafforet compared his birds to a thrush
and not to some other similarly-sized bird – a quail
or a grosbeak
for example – at least suggests that they were rather thrush-like in habitus
, and thus probably belonged to the basal Passeri or the Muscicapoidea, and not to the Sylvioidea, let alone the often colourful and sexually dimorphic and/or "finch
"-like Passeroidea. Even the latter have, however, evolved an island taxon
with highly unusual feeding habits (the Vampire Finch
Geospiza difficilis septentrionalis). On account of the vocalisations, a placement with the Sturnidae seems indeed more likely than with more basal Passeri: the latter generally have harsh voices, while starlings' songs are indeed composed of a lively, diverse and usually quite musical chatter. It is interesting to note, though, that Tafforet did not compare the vocalizations more explicitly to those of e.g. the European Starling, a very widespread and common bird he almost certainly knew.
The corvid hypothesis advanced by Masauyi Hachisuka can probably be dismissed outright as a somewhat bizarre case of confirmation bias
. First, his reasoning is generally tenuous, and even if it is accepted applies equally or more so to the better candidates – e.g. Prionopidae or (if one takes into account adaptation
to the harsh island habitat) Sturnidae. Second, the White-winged Chough
(Corcorax melanorhamphos) is nowadays known neither to be a real chough
(Pyrrhocorax) nor a corvid at all, and any perceived similarities of this bird to Tafforet's description cannot be used to argue for a corvid relationship. Third, corvids appear to be of Southeast Asia
n origin, and though they are widely found throughout the Holarctic
and the Americas
, they are not very diverse in the regions from where the Mascarenes avifauna originated – and all their species found in southern India
and southeastern Africa
today belong to the crow and raven genus
Corvus. Though these are known to be susceptible to island dwarfing and to developing black-and-white plumage they still make an unlikely ancestor for a thrush-like bird with a musical song (a fact that Hachisuka disregarded). Finally, the general improbability of two similarly-sized and somewhat carnivorous passerine
s (as can be deduced from Tafforet's account and the beak
shape of the fossils) evolving on such a small island with its limited food resources suggests very strongly that Tafforet's bird was the same as the subfossil
species. This also agrees with the fact that the native passerine birds of Rodrigues had largely non-overlapping ecological niche
s, and that introductions of passerine birds to the island have met with below-average success even to this day.
Though there is no direct evidence that the bones are from the same species
as Tafforet's birds, the absence of another suitable extinct or extant candidate and the severe competitive exclusion on such a resource-poor island like Rodrigues
make it rather likely. No similar bird is known from elsewhere in the Mascarenes, excluding the possibility that the Rodrigues records refer to an ephemeral
population of vagrants.
The birds found by Tafforet's party lived on the Île au Mât (today Île Gombrani – sometimes transcribed "Combrani", "Gombranis" or "Mombrani"), an offshore islet of Rodrigues. The bones were found in caves on the Plaine Corail, the island's southwestern calcarenite
limestone
plateau east of today's Sir Gaëtan Duval Airport. Île Gombrani is due southeast offshore the Plaine Corail; consequently, the bird must have been fairly numerous at least on the island's southwestern end in former times. The close geographical and ecological association of Tafforet's record and the bones further supports the assumption that all records refer to a single species.
In his report, Tafforet asserted however that he did not encounter his Île Gombrani bird on mainland Rodrigues. He mentions some that were kept by his party, perhaps indicating that the breeding season so coincided with his 9-month visit for easily-caught fledglings to be present. No mention is made of nesting sites on Gombrani, but even 30 years earlier few small birds were found to nest on mainland Rodrigues on account of the rats (see below). While N. rodericanus might have been a ground-nester, this is not so likely; its presumed relatives are generally tree-nesting birds and starlings in particular are often cavity-nesters. There is, however, some woodland on Île Gombrani even today, and the abundant shrubs would have provided ample nesting sites. It is sometimes asserted as certain that the birds kept by Tafforet's party were not adult, but that is conjecture; the original text is ambiguous in that respect. With no report of nesting whatsoever, all that can be said is that Tafforet's encounter probably coincided with the end of the breeding season, after the young had fledged – if N. rodericanus was not easily caught even as adults, which is well possible
and was noted in many Mascarene birds (including Fregilupus varius).
As regards habitat
, today the Plaine Corail is largely pasture
and other grassland
, with sparse settlement. In the late 19th century it was even less accessible, and had an abundant growth of shrubs and small trees. Much of its original vegetation is shared by the islets offshore western and southern Rodrigues, and this allows to assess what plants grew in the birds' habitat. Among trees and shrubs that might have been used for nesting, native species almost certainly present were the dicots Gastonia rodriguesiana
(Apiales
), Grand Devil's-claws (Pisonia grandis, Caryophyllales
), Bay Cedar (Suriana maritima, Fabales
), Conkerberry (Carissa spinarum) and Antirhea bifida (Gentianales
), Tree Heliotrope (Heliotropium foertherianum, Lamiales
), Ludia mauritiana (Malpighiales
), Portia Tree
(Thespesia populnea, Malvales
), Pemphis acidula (Myrtales
), Zanthoxylum paniculatum (Sapindales
), and Lycium mascarenense (Solanales
). Monocots were not certainly present in significant numbers; they might have included the Hurricane Palm (Dictyosperma album var. aureum, Arecales) and Pandanus heterocarpus of the Pandanales
.
With the forest on the Plaine Corail less dense than on the rest of the island, ground cover must have been abundant even when more trees were present. Native herbaceous
dicots that provided cover, possibly nesting grounds and maybe supplementary food for the birds include Psiadia rodriguesiana and Rhamphogyne rhynchocarpa (Asterales
), Aerva congesta and Achyranthes aspera
var. argentea (Caryophyllales), Hypoestes inconspicua and Nesogenes decumbens (Lamiales), Oldenlandia sieberi var. congesta (Gentianales), and White-edged Morning Glory (Ipomoea nil) and I. rubens (Solanales). Euphorbia thymifolia (Malpighiales) and Ipomoea leucantha might be native, or introduced by early visitors. Poales
of note on Îsle Gombrani and the Plaine Corail are the Tropical Fimbry (Fimbristylis cymosa ssp. cymosa, a sedge
), and Bermuda Grass (Cynodon dactylon) and Stenotaphrum
sp. which are true grasses. The only significant basal tracheophyte in this habitat is the spikemoss
Selaginella balfourii.
Tafforet was not sure why the birds were absent from Rodrigues proper, though he was inclined to attribute it to birds of prey scaring off N. rodericanus. This might refer to migrant
falcon
s (Falco), vagrant Réunion Harrier
s (Circus maillardi) which were more widespread in the Mascarenes in former times, and of course to the resident Rodrigues Owl
(Mascarenotus murivorus). The former two, with their presence only temporary, are unlikely to have exerted a marked evolution
arly pressure on such a sizable endemic resident landbird. The owl on the other hand was not much larger than N. rodericanus and though probably able to subdue them would – in particular its smaller (Morepork-sized) males – have preferred less hefty victims. These were abundant among the native birds, namely the Rodrigues Warbler
(Acrocephalus rodericanus) and Rodrigues Fody which both still survive, and perhaps the bulbul
and the "Old World babbler
" which went extinct at an unknown (but probably early) date. Even the small pigeons that used to inhabit Rodrigues would likely have made as good prey to any raptor as did Tafforet's large passerine with its meat-ripping bill. Thus, predation pressure by carnivorous landbirds was probably less significant for N. rodericanus than for the other native passerines. On the other hand, frigatebird
s were earlier noted to frequent the mainland to hunt hatchling
sea turtle
s and to bully boobies for food at dusk, so it may be those Tafforet had in mind. It is unlikely
that the large passerine observed by Tafforet was originally confined to the islet, though seasonally it may have well been so. Overall, the absence of the bird from Rodrigues proper in 1725 is somewhat puzzling, but it may indicate an already-precarious state of the mainland fauna of Rodrigues (see also below).
[ seabird
] eggs or some turtles dead of hunger", and they apparently made effective use of the stout beak
in foraging, tearing turtle flesh from the shells and presumably breaking open eggs. The (possibly young) birds kept by his party were given seeds of some tree and chopped-up cooked meat – possibly salt pork
, beef
or mutton which were the standard fare for ocean voyages at that time, but perhaps more likely turtle and tortoise meat procured on the island, as his group was effectively stranded on Rodrigues. Tafforet notes that the birds preferred the meat. Since it is unclear what vegetable food precisely Tafforet's party offered the birds, nothing can be said for certain on this. However, it is clear that the birds were at least not exclusively vegetarian. The skull shows an attachment scar above the temporal fossa
which indicates it was used for "gaping" and forceful probing as in starlings. The supraoccipital ridge on the skull is quite strongly developed and a biventer muscle attachment in the parietal
region below it is conspicuous. This indicates strong neck and jaw muscles, agreeing well with how Tafforet describes the birds' procuring meat from dead turtles. The presumably related Bourbon Crested Starling
(Fregilupus varius) had also notably robust neck and jaw muscles and a good "gaping" ability.
These "turtles dead of hunger" may have been the giant tortoise
s then found on Rodrigues, but perhaps more likely Green Turtles (Chelonia mydas) and Hawksbill Turtle
s (Eretmochelys imbricata). The abundant vegetation on Île Gombrani is unlikely to have allowed land tortoises to starve even if they were able to reach the islet (which is not certain). Seabirds whose eggs would have been technically available as food to N. rodericanus were the Brown Noddy
(Anous stolidus), Lesser Noddy
(A. tenuirostris), White Tern
(Gygis alba) and Roseate Tern
(Sterna dougallii) which still are found on and around Rodrigues, as well as the Indopacific/Indian Ocean Sooty Tern
(Onychoprion fuscatus nubilosus), Abbot's Booby (Papasula abbotti) and the Red-footed Booby
(Sula sula) which are now extirpated or uncertain breeders on Rodrigues but were recorded by Tafforet and others. The Great Frigatebird
(Fregata minor) and perhaps also the Lesser Frigatebird
(F. ariel) were formerly recorded on Île Gombrani, but only to prey on other birds' eggs; though they bred on nearby Île Frégate, these aggressive birds are unlikely to have their eggs attacked successfully by a passerine. Bourne's Petrel (? Pterodroma sp.) which is entirely extinct, as well as the extirpated Barau's Petrel
(P. baraui) and Mascarene Petrel (Pseudobulweria aterrima), seem to have nested near the top of Rodrigues' mountains in burrow
s, and their eggs were thus inaccessible to avian
predators. Whether the eggs of the Wedge-tailed Shearwater
(Puffinus pacificus), White-tailed Tropicbird
(Phaeton lepturus) and Red-tailed Tropicbird
(P. rubricauda) – cavity-nesters still breeding on offshore islets of Rodrigues – would have been readily available prey for N. rodericanus is doubtful. With Île Gombrani formerly noted for its abundance of Sooty Terns, it seems that this species yielded most of the "eggs of the fishing birds" Tafforet mentions as staple food of his songbird. Particularly the noddies
, noted for their extremely docile behaviour, make notable secondary candidates.
But although the seabirds managed to raise three broods in some years at least (as attested by Leguat), given that eggs cannot always have been available and considering that Tafforet does not note his birds to refuse the seeds entirely, N. rodericanus obviously ate some other food. Notable native plants of its habitat, which might have furnished fruits or seeds to complement its diet, are listed above. Apart from the occasional hatchling gecko
or turtle, invertebrate
s probably made up much of the remaining animal food of this bird. The birds are likely to have preyed on the larger-sized of the native arthropod
fauna – spider
s, millipede
s, centipede
s, beetle
s, butterflies and moth
s – or more likely their caterpillars – Orthoptera
, Hymenoptera
, Hemiptera
, damselflies
, the Madagascan Marbled Mantis (Polyspilota aeruginosa), the stick insect Xenomaches incommodus – which is apparently also extinct today –, and presumably the antlion
Myrmeleon obscurus.
It is not certain whether the viviparous flesh-flies (Sarcophagidae) Leguat noted were native or early introductions; the mysterious and supposedly native Sarcophaga mutata might simply have been the globally widespread Red-tailed Flesh-fly (S. haemorrhoidalis). Otherwise, perhaps apart from the mid-sized Aegophagamyia remota, Odontomyia nigrinervis and Villa sexfasciata, no Diptera
large and lumbering enough to make easy prey for Tafforet's bird seem to have been indigenous to Rodrigues. Terrestrial
crustacean
s were largely absent too; perhaps only the apparently native woodlouse
of genus Oniscus
or Porcellio
would have been available. There were similarly few annelid
s; at least in the woodlands the large earthworm
Amynthas rodericensis was abundant, but it is unclear whether the birds foraged in such habitat often.
The larger Muscicapoidea – mimid
s, trushes and starling
s – are noted for including an unusual amount of land snail
s in their diet; some are expert in cracking open snail shells using their bill and tools such as small stones. Such potential prey was rather abundant on Rodrigues in former times. Namely the genera
Gonospira
of the Streptaxidae
and Tropidophora
of the Pomatiidae
have undergone adaptive radiation
on the island. Also large enough to furnish food for Tafforet's birds and native to Rodrigues were the possibly extinct Achatinellidae
Elasmias jaurffreti
, the Euconulidae
Dancea rodriguezensis
(extant) and Plegma bewsheriana (extinct), an extinct large Pupilla
sp. (Pupillidae
), and the and the slug
Vaginula rodericensis (Veronicellidae
). The now-extinct snail species are plentiful in the same caves on the Plaine Corail where the bones of N. rodericanus were found. It has never been studied whether some of the snail shell pieces recovered were smashed by birds; for the time being, it can thus only be noted that none of the other native birds of Rodrigues are known or suspected to have utilized the abundant terrestrial Gastropoda
of the island as food resource.
for the extinction is established. It is more difficult to assess final extinction dates, as some remnant population may linger on for a long time (see also Lazarus taxon
). However, Rodrigues is a small island, and was often visited throughout the 18th century to capture tortoise
s and sea turtle
s (until Cylindraspis peltastes
and C. vosmaeri
went extinct about 1800, too). By 1740, a major trade in these had developed, as their relatives
on the other Mascarene islands were already gone or nearly so. The island must thus have been surveyed to a considerable degree by the mid-18th century. When A. G. Pingré
during the French
1761 Transit of Venus expedition observed the seabird colonies of Île Gombrani in 1761, he found them still healthy; no trace of Tafforet's bird was noted, however, while the burgeoning Testudines-based economy of the island offered little other food than tortoise dishes in the nearly 15 weeks he stayed. Neither did Philibert Marragon see the birds some decades later; he already remarked upon the tortoises' impending extinction though. Quite likely, N. rodericanus became extinct within one decade of 1740.
That Tafforet did not encounter it on the main island, with a population essentially confined to one or a few islets and vulnerable to any stochastic
catastrophe such as a tsunami
or Mauritius cyclone, is suggestive of an extinction shortly thereafter. It is uncertain, however, whether his survey of the inhospitable Plaine Corail region was thorough enough to find any birds remaining there. François Leguat
, who was marooned with his companions in 1691–1693 on the north coast where now is Port Mathurin
, does not explicitly mention the birds either in his extensive writings. Though his party visited most accessible parts of the island, he does not mention the striking karst
-like landscape of the Plaine Corail – a major tourist attraction today –, and probably only saw it from a distance. He discusses a low-lying plain of several square kilometers, but as he extols the richness of its deep soil and ample tree-cover the La Ferme region – extensively logged
nowadays, but then still pristine –, where several small rivers have deposited abundant sediment
s, makes a far better match for this locality.
This may be taken to suggest that the birds were in fact confined to the island's southwest, and perhaps only common on offshore islets, as early as 1690. Of the latter, Leguat visited several, almost certainly including Île aux Diamants and the sandy islet next to Port Mathurin's harbour, perhaps Île aux Fous north of these at the reef edge, as well as some well-wooded islets which were most likely Île aux Cocos
and Île aux Sables northwest of the mainland. He described the multitude of birds nesting on the latter. Gombrani is hard to reach on foot without crossing the Plaine Corail with its numerous sinkhole
s and cave
s (neither of which is mentioned in Leguat's report), and though having some trees is at least today mainly covered in lower vegetation. Also, Leguat does not discuss the Rodrigues Warbler
(Acrocephalus rodericanus), which must in his time have inhabited the mainland where it is still present today (albeit precariously rare), and thus there are some places on the mainland he did not visit.
He mentions seeing the Rodrigues Fody
(Foudia flavicans) but no other songbirds except "very few swallow
s" – most likely vagrant Mascarene Martin
s (Phedina borbonica). These resemble the grey-brown Crag Martin
(Ptyonoprogne rupestris) that is not rare in France
. However, with the colour pattern described by Tafforet, N. rodericanus may well have resembled the black-and-white House Martin
(Delichon urbicum) – the most common swallow in European cities and towns – if seen in flight from below. Thus, it is not entirely certain that Leguat never encountered the "starling". What can be said is that the absence of Tafforet's bird in Leguat's detailed testimony is best explained by its general absence from the Port Mathurin region – and perhaps the rest of the island, or most of it – in 1691–1693.
In general, the cause of the birds' disappearance was almost certainly some introduced species, rather than habitat destruction
or overhunting, as the reports of the first long-term inhabitants contain no mention of the bird any more. Feral goat
s and other likely candidates were only present after Leguat's visit, but he noted the large numbers of rat
s, for which he had no satisfying explanation (but see below). The initial rat population has been identified from old bones as Black Rat
s (Rattus rattus), though starting in the late 18th century these were probably replaced by the Brown Rat
(R. norvegicus) which predominates today. As a tree-climbing predator of nestlings and egg
s, the Black Rat would certainly represent a major threat to any insular endemic songbird. Species likely to have carried avian diseases to Rodrigues were not introduced until after the disappearance of N. rodericanus, and thus it seems as good as certain that Tafforet's bird was killed off by the Black Rat, succumbing when these finally reached the offshore islets. At Leguat's time, he noted that the islands he visited seemed rat-free, and he reasoned that the Rodrigues Grey Pigeon
("Alectroenas" rodericana) nested only there because on the mainland rats were already too numerous.
It is not clear when Black Rats arrived on the island. Leguat's report is the first comprehensive one, and he mentions the main island overrun with them – and he does not mention the bulbul
and presumed Old World babbler
that once lived there. While Arabic, Swahili
and maybe Pandyan sailors knew Rodrigues as (probably) Diva Harab ("Desert Island") before the 16th century, the Late Medieval voyages of the Indian Ocean
trade seem quite long ago even for the extreme overpopulation
of rats observed by Leguat to develop. The island was relocated by Portugal
in 1507 and visited (mainly by Dutch
ships) occasionally from 1601 on; Leguat mentions inscriptions cut by Dutch sailors in the bark
of several trees.
With N. rodericanus as rare as to be overlooked for two years in 1693, still extant in 1725, but extinct shortly thereafter, and some mainland birds apparently already extinct by 1691, it was probably roughly between 1550 and 1650 that the Black Rat settled Rodrigues.
Songbird
A songbird is a bird belonging to the suborder Passeri of the perching birds . Another name that is sometimes seen as scientific or vernacular name is Oscines, from Latin oscen, "a songbird"...
species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
. It is the only valid species in genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Necropsar, and provisionally assigned to the starling
Starling
Starlings are small to medium-sized passerine birds in the family Sturnidae. The name "Sturnidae" comes from the Latin word for starling, sturnus. Many Asian species, particularly the larger ones, are called mynas, and many African species are known as glossy starlings because of their iridescent...
family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
(Sturnidae). This bird used to inhabit Rodrigues
Rodrigues
Rodrigues is a common surname in the Portuguese language. It was originally a Patronymic, meaning Son of Rodrigo or Son of Rui. The "es" signifies "son of". The name Rodrigo is the Portuguese form of Roderick, meaning "famous power" or "famous ruler", from the Germanic elements "hrod" and "ric" ,...
in the Mascarenes and at least one of its offshore islet
Islet
An islet is a very small island.- Types :As suggested by its origin as islette, an Old French diminutive of "isle", use of the term implies small size, but little attention is given to drawing an upper limit on its applicability....
s. The record of its erstwhile existence is limited to an old travel report and a few handfuls of subfossil bones.
In 1726 or shortly thereafter, the French naval officer Julien Tafforet of the La Ressource described his encounters with the bird on an offshore islet in the Relation d'île Rodrigue, which documented his 9-month stay in 1725. In 1874, Reverend Henry Horrocks Slater, a naturalist
Naturalist
Naturalist may refer to:* Practitioner of natural history* Conservationist* Advocate of naturalism * Naturalist , autobiography-See also:* The American Naturalist, periodical* Naturalism...
of the British
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
Transit of Venus
Transit of Venus
A transit of Venus across the Sun takes place when the planet Venus passes directly between the Sun and Earth, becoming visible against the solar disk. During a transit, Venus can be seen from Earth as a small black disk moving across the face of the Sun...
expedition, found subfossil
Subfossil
Subfossil refers to remains whose fossilization process is not complete, either for lack of time or because the conditions in which they were buried were not optimal for fossilization....
bones of a starling-like songbird on Rodrigues proper, as had magistrate
Magistrate
A magistrate is an officer of the state; in modern usage the term usually refers to a judge or prosecutor. This was not always the case; in ancient Rome, a magistratus was one of the highest government officers and possessed both judicial and executive powers. Today, in common law systems, a...
George Jenner shortly before. These are generally assumed to belong to the bird Tafforet wrote about. Some additional bones were found in 1974. Together, they represent most of the skeleton, except for the spine
Vertebral column
In human anatomy, the vertebral column is a column usually consisting of 24 articulating vertebrae, and 9 fused vertebrae in the sacrum and the coccyx. It is situated in the dorsal aspect of the torso, separated by intervertebral discs...
, pelvis
Pelvis
In human anatomy, the pelvis is the lower part of the trunk, between the abdomen and the lower limbs .The pelvis includes several structures:...
and the small bones, and are mainly in the Cambridge Museum. The IUCN regards the Rodrigues Starling as a valid species, because Tafforet's report and the bones provide compelling evidence that it existed.
N. rodericanus was frequently confused with a supposedly related but smaller species "N. leguati", described with specimen D.1792, a skin in the World Museum Liverpool
World Museum Liverpool
World Museum is a large museum in Liverpool, England which has extensive collections covering archaeology, ethnology and the natural and physical sciences. Special attractions include the Natural History Centre and a free Planetarium. Entry to the museum itself is also free...
, as holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
. This was also called "White Mascarene Starling" and variously considered a distinct parapatric or allopatric species, an immature, a colour morph or a female. It led some to believe that the Rodrigues Starling became extinct only about 1830, when the Liverpool specimen was collected. D.1792, however, was eventually identified as an albinistic individual of the Martinique Trembler (Cinclocerthia gutturalis).
Description
According to Tafforet, the bird was slightly larger than the Common Blackbird (Turdus merula) he knew from FranceFrance
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
. This would imply a total length of about 25–30 cm, and a weight of perhaps 90-130 g. Judging from the bones, the bird was about 10% smaller than the Bourbon Crested Starling
Bourbon Crested Starling
The Bourbon Crested Starling , also known as Huppe, Crested Starling, or Réunion Starling is an extinct bird from the family of Sturnidae.-Description:...
(Fregilupus varius), its presumed closest relative. Consequently, its length would have been about 25–28 cm and its weight perhaps 100-120 g when adult.
Its skeleton
Skeleton
The skeleton is the body part that forms the supporting structure of an organism. There are two different skeletal types: the exoskeleton, which is the stable outer shell of an organism, and the endoskeleton, which forms the support structure inside the body.In a figurative sense, skeleton can...
largely agreed with F. varius in proportions, but differed in some details. The skull
Skull
The skull is a bony structure in the head of many animals that supports the structures of the face and forms a cavity for the brain.The skull is composed of two parts: the cranium and the mandible. A skull without a mandible is only a cranium. Animals that have skulls are called craniates...
was shaped somewhat differently, being longer (about 29 mm long from the occipital condyle
Occipital condyle
The occipital condyles are undersurface facets of the occipital bone in vertebrates, which function in articulation with the superior facets of the atlas vertebra....
), narrower (21–22 mm), with the eyes set slightly lower, the upper rims of the eye sockets being some 8 mm apart. The interorbital septum was more delicate, with a larger hole in its center. The bill was about 36–39 mm long, less curved than in F. varius and proportionally a bit deeper, and seems to have had larger nostril
Nostril
A nostril is one of the two channels of the nose, from the point where they bifurcate to the external opening. In birds and mammals, they contain branched bones or cartilages called turbinates, whose function is to warm air on inhalation and remove moisture on exhalation...
s, with the nostril openings in the bone 12–13 mm in length. The mandible
Mandible
The mandible pronunciation or inferior maxillary bone forms the lower jaw and holds the lower teeth in place...
was about 52–60 mm long and 4–5 mm deep proximally. Its ulna
Ulna
The ulna is one of the two long bones in the forearm, the other being the radius. It is prismatic in form and runs parallel to the radius, which is shorter and smaller. In anatomical position The ulna is one of the two long bones in the forearm, the other being the radius. It is prismatic in form...
was somewhat shorter by comparison – measuring 37–40 mm versus 32–35 mm for the humerus
Humerus
The humerus is a long bone in the arm or forelimb that runs from the shoulder to the elbow....
– and the keel on its sternum
Sternum
The sternum or breastbone is a long flat bony plate shaped like a capital "T" located anteriorly to the heart in the center of the thorax...
was a bit lower, but its power of flight was not reduced. It had strong quill knobs on the ulna, indicating the secondary remiges were well-developed. One coracoid measured 27.5 mm in length, and one carpometacarpus
Carpometacarpus
The carpometacarpus is the fusion of the carpal and metacarpal bone, essentially a single fused bone between the wrist and the knuckles. It is a smallish bone in most birds, generally flattened and with a large hole in the middle. In flightless birds, however, its shape may be slightly different,...
was 22.5 mm long. The leg and feet had the same proportions in both; in N. rodericanus the femur
Femur
The femur , or thigh bone, is the most proximal bone of the leg in tetrapod vertebrates capable of walking or jumping, such as most land mammals, birds, many reptiles such as lizards, and amphibians such as frogs. In vertebrates with four legs such as dogs and horses, the femur is found only in...
measured around 33 mm, the tibiotarsus
Tibiotarsus
The tibiotarsus is the large bone between the femur and the tarsometatarsus in the leg of a bird. It is the fusion of the proximal part of the tarsus with the tibia.A similar structure also occurred in the Mesozoic Heterodontosauridae...
52–59 mm, and the tarsometatarsus
Tarsometatarsus
The tarsometatarsus is a bone that is found in the lower leg of certain tetrapods, namely birds.It is formed from the fusion of several bones found in other types of animals, and homologous to the mammalian tarsal and metatarsal bones...
36–41 mm.
The head and body plumage was white; tail and wings were partially black. Presumably, this included the flight feather
Flight feather
Flight feathers are the long, stiff, asymmetrically shaped, but symmetrically paired feathers on the wings or tail of a bird; those on the wings are called remiges while those on the tail are called rectrices . Their primary function is to aid in the generation of both thrust and lift, thereby...
s, which are generally rich in eumelanin polymer
Polymer
A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...
s that make the feather more robust. The wing- and tail-tips are, for example, even black in the Bali Myna (Leucopsar rothschildi), a starling
Starling
Starlings are small to medium-sized passerine birds in the family Sturnidae. The name "Sturnidae" comes from the Latin word for starling, sturnus. Many Asian species, particularly the larger ones, are called mynas, and many African species are known as glossy starlings because of their iridescent...
with otherwise entirely white plumage. It is not known whether the non-black (presumably white) part of the wings was a patch or wing-stripe, or simply the wing coverts or fringes or one vane
Pennaceous feather
Pennaceous feathers are also known as contour feathers. This type of feather is present in most modern birds, and has been shown in some species of maniraptoran dinosaurs....
, as is commonly seen in birds in general. Reconstructions tend to show the tail with black tips and lighter feather bases. But while this is more likely than white-ended black rectrices, these too are seen in some birds and thus the tail pattern is essentially conjectural; it might just as well have had white fringes or vanes for example. The beak
Beak
The beak, bill or rostrum is an external anatomical structure of birds which is used for eating and for grooming, manipulating objects, killing prey, fighting, probing for food, courtship and feeding young...
, as well as the feet, were reported as yellow by Tafforet.
Tafforet makes no mention of marked sexual dimorphism
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
, or of a pronouncedly different juvenile plumage. His 9-month visit is likely to have encompassed at least part of the breeding season (but see below), and if so almost certainly a time where postbreeding moult
Moult
In biology, moulting or molting , also known as sloughing, shedding, or for some species, ecdysis, is the manner in which an animal routinely casts off a part of its body , either at specific times of year, or at specific points in its life cycle.Moulting can involve the epidermis , pelage...
took place and when immature birds were around. Thus it may very well be that outward sexual and age differences were subdued or absent in N. rodericanus. The Bourbon Crested Starling had no pronounced sexual dichromatism either, but immature birds had a buff
Buff (colour)
Buff is a pale yellow-brown colour that got its name from the colour of buff leather.Displayed on the right is the colour buff.EtymologyAccording to the Oxford English Dictionary, buff as a descriptor of a colour was first used in the London Gazette of 1686, describing a uniform to be "A Red Coat...
y tinge. The beak of its adult females was about one-tenth shorter than in males; it may be that this was due to niche partitioning to better utilize the limited resources of its island home (see also Huia
Huia
The Huia was the largest species of New Zealand wattlebird and was endemic to the North Island of New Zealand. Its extinction in the early 20th century had two primary causes. The first was rampant overhunting to procure Huia skins for mounted specimens, which were in worldwide demand by...
). Too few skull remains of N. rodericanus have been found to date to assess whether it was similarly dimorphic. Among its limb bones – of which a larger number is known – the smallest do in fact measure 10% less than the largest.
The vocalizations are described by Tafforet as "a marvellous twitter [of] many and altogether different and all very joyful [calls]".
Taxonomy and nomenclature
The bones found by Slater's team were the basis of the first scientific discussion by Albert Günther and Alfred NewtonAlfred Newton
Alfred Newton FRS was an English zoologist and ornithologist.Newton was Professor of Comparative Anatomy at Cambridge University from 1866 to 1907...
in 1879. According to Günther and Newton, the Rodrigues bird was closely related to the Bourbon Crested Starling
Bourbon Crested Starling
The Bourbon Crested Starling , also known as Huppe, Crested Starling, or Réunion Starling is an extinct bird from the family of Sturnidae.-Description:...
(Fregilupus varius). Several authors have intimated that they would rather have placed the species in Fregilupus, but none seem to have actually done so. Even though James Greenway
James Greenway
James Cowan Greenway was an American ornithologist. An eccentric, shy and sometimes reclusive man, his survey of extinct and vanishing birds provided the base for much subsequent work on bird conservation.-Early years:...
listed N. rodericanus as a junior synonym of F. varius, his description indicates that this was an inadvertent error. The 1974 bones allowed for a more thorough assessment, verifying that the Rodrigues bird is appropriately placed in the monotypic
Monotypic
In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...
genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Necropsar, established by Slater in 1879. In 1900, believing Necropsar to be a mis-spelling, G. E. Shelley
George Ernest Shelley
Captain George Ernest Shelley was an English geologist and ornithologist. He was a nephew of the poet Percy Bysshe Shelley....
"corrected" it to Necrospa and attributed it – erroneously – to Philip Sclater
Philip Sclater
Philip Lutley Sclater was an English lawyer and zoologist. In zoology, he was an expert ornithologist, and identified the main zoogeographic regions of the world...
. He also gave the authors of the species name as Günther and Newton, but their original text assigns authorship to Slater.
Masauyi Hachisuka, believing the carnivorous habits described by Tafforet to be unlikely for a starling and the lack of a crest suggesting against a close relationship with Fregilupus. He was reminded of corvids by the black-and-white plumage, and assumed the bird seen in 1725 was some sort of "chough
Chough
The Red-billed Chough or Chough , Pyrrhocorax pyrrhocorax, is a bird in the crow family; it is one of only two species in the genus Pyrrhocorax...
". These at his time were often still held to include the White-winged Chough
White-winged Chough
The White-winged Chough is one of only two surviving members of the Australian mud-nest builders family, Corcoracidae, and is the only member of the genus Corcorax...
(Corcorax melanorhamphos) – which is actually not a corvid – and the "ground choughs" (Podoces). Still, Hachisuka believed Günther's and Newton's assessment regarding the bones to be accurate, only that according to him Tafforet's record could not have pertained to that bird. Thus, in 1937 he described the hypothetical "chough" as Testudophaga bicolor ("Bi-coloured Chough"). Hachisuka's assumptions are generally disregarded today for a number of reasons (see below).
Systematics
Molecular phylogenetic analysis confirms Fregilupus varius to be a starlingStarling
Starlings are small to medium-sized passerine birds in the family Sturnidae. The name "Sturnidae" comes from the Latin word for starling, sturnus. Many Asian species, particularly the larger ones, are called mynas, and many African species are known as glossy starlings because of their iridescent...
; the affiliations of N. rodericanus, presumably but not certainly closely related to it, have been open to more dispute. Mid-20th century studies found some similarities between the Bourbon Crested Starling and the Prionopidae (helmetshrikes and woodshrikes). These are in the fairly basal songbird superfamily Corvoidea, and thus among the Passeri not at all closely related to starlings, which are more advanced songbirds in superfamily Muscicapoidea of the infraorder Passerida
Passerida
Passerida is under the Sibley-Ahlquist taxonomy, one of two "parvorders" contained within the suborder Passeri...
. The Necropsar bones, while indeed reminiscent of Fregilupus (and the Prionopidae), remind much more of a starling's though.
In recent times, several songbirds of the Madagascar
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
region, whose relationships were believed to have been resolved, were instead found to be part of the vanga
Vanga
The vangas are a group of little-known small to medium-sized passerine birds restricted to Madagascar and the Comoros. They are usually classified as the family Vangidae. There are about 22 species, depending on taxonomy...
s (Vangidae) or the as of 2009 unnamed "Malagasy warbler
Malagasy warbler
The Malagasy warblers are a newly validated clade of songbirds. They were formally named Bernieridae in 2010. The family consists of ten species of small forest birds and is endemic to Madagascar....
s". These have both undergone spectacular adaptive radiation
Adaptive radiation
In evolutionary biology, adaptive radiation is the evolution of ecological and phenotypic diversity within a rapidly multiplying lineage. Starting with a recent single ancestor, this process results in the speciation and phenotypic adaptation of an array of species exhibiting different...
s and might conceivably have evolved an insular starling-like form. Phylogenetically, an affiliation between the "Mascarene starlings" and either of the two Malagasy radiations – or the Prionopidae, for that matter – cannot be discounted as yet, in particular as no detailed comparisons seem to have ever been made.
Biogeographically, the Mascarenes avifauna
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
has either affiliations with birds from Madagascar and Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
, or with South Asia
South Asia
South Asia, also known as Southern Asia, is the southern region of the Asian continent, which comprises the sub-Himalayan countries and, for some authorities , also includes the adjoining countries to the west and the east...
n lineages. The latter, however, is more common in older endemics, such as the dodos (Raphinae). While an African origin of the "Mascarene starlings" is thus more likely than a South Asian one, even this does not help much to narrow their relationships, as all possible relatives are native to Africa, and in case of the Sturnidae and Prionopidae also to South Asia.
As regards plumage, the White Helmetshrike
White Helmetshrike
The White-crested Helmetshrike , also known as the White Helmetshrike, is a species of passerine bird in the helmetshrike family Prionopidae, formerly usually included in the Malaconotidae.-Distribution and habitat:...
(Prionops plumatus) bears an uncanny resemblance to an imagined "hybrid" between the two "Mascarene starlings", with an overall coloration recalling Tafforet's description and a crest like F. varius. Among the vangas, species of Artamella, Falculea, Leptopterus and Vanga
Hook-billed Vanga
The Hook-billed Vanga is a species of bird in the Vangidae family. It is endemic to Madagascar. Its natural habitats are subtropical or tropical dry forests, subtropical or tropical moist lowland forests, and subtropical or tropical moist montane forests.-References:* BirdLife International 2004. ...
have a similar coloration. But while most of the Afro-Asiatic lineage of starlings are either brownish-grey or have dark metallic hues, there are some light-bodied black-winged species found among them too, e.g. in the genera Creatophora, Speculipastor and Sturnia
Sturnia
Sturnia is a genus of Asian birds in the family Sturnidae. It is sometimes merged with Sturnus.-Species:The old genus placements with the starlings was found to be polyphyletic resulting in changes in the placement...
. Consequently, the striking color pattern of Tafforet's birds is of little use in determining their relationships (except perhaps by suggesting against a close relationship to the "Malagasy warblers", which are predominantly greenish).
Anatomy
Anatomy
Anatomy is a branch of biology and medicine that is the consideration of the structure of living things. It is a general term that includes human anatomy, animal anatomy , and plant anatomy...
is quite characteristically autapomorphic among Passeriformes in general, but a few phylogenetic patterns can be discerned. Naturally, only Fregilupus varius can be studied in detail today. What can be said is that this species' overall myology
Myology
The muscular system consists of skeletal muscle that act to move or position parts of the body , or smooth and cardiac muscle that propels, expels, or controls the flow of fluids and contained substance.The British Myology Society is an example of a professional group promoting myology ...
and osteology
Osteology
Osteology is the scientific study of bones. A subdiscipline of anatomy, anthropology, and archeology, osteology is a detailed study of the structure of bones, skeletal elements, teeth, morphology, function, disease, pathology, the process of ossification , the resistance and hardness of bones , etc...
and pterylosis is altogether passeriform. Pterylosis is no reliable trait to discern more detailed relationships, and in fact the Bourbon Crested Starling in this regard resembled a – clearly not very closely related – sickletail bird of paradise
Cicinnurus
The genus Cicinnurus consist of three Sickletails Bird of paradise.All three species are sexually dimorphic and have bright blue legs and feet.-Species:* King Bird-of-paradise,...
(Cicinnurus) more than either the White-headed Vanga, the basal sturnid Aplonis tabuensis (Polynesian Starling), or the more advanced European Starling
European Starling
The Common Starling , also known as the European Starling or just Starling, is a passerine bird in the family Sturnidae.This species of starling is native to most of temperate Europe and western Asia...
(Sturnus vulgaris). The wing myology of passerine birds is rather uniform; compared to the three other taxa F. varius is fairly autapomorphic and does not agree consistently either with the starlings or the vanga. The pelvis and leg muscles of F. varius are even more strongly autapomorphic versus the comparison taxa, otherwise agreeing more with starlings than with Artamella. Its foot and toe muscles are notably more similar to starlings, at least where no different perching styles have obscured any phylogenetic pattern.
Fregilupus varius seems to have some synapomorphies with the more advanced Passerida
Passerida
Passerida is under the Sibley-Ahlquist taxonomy, one of two "parvorders" contained within the suborder Passeri...
– Muscicapoidea and Passeroidea. Its tenth (outermost) primary remex is quite reduced for example. This feature is characteristically found in Passerida, but varies in extent, with the basal lineages have little reduction in length, and many nine-primaried oscine
Nine-primaried oscine
The nine-primaried oscines are a group of songbird families from the superfamily Passeroidea. It is composed of the Fringillidae , Emberizidae , Parulidae , Thraupidae , Cardinalidae , Icteridae and the monotypic Peucedramidae...
s of the Passeroidea having lost that feather altogether. The pattern of scales on its feet also indicates a position among the Passerida at least. But these traits cannot be known for the Rodrigues bird of course. However, as F. varius, Muscicapoidea and Passeroidea have an apparently apomorphic divided fossa tricipitalis of the proximal humerus head. This serves as attachment point for the triceps brachii muscle
Triceps brachii muscle
The triceps brachii muscle is the large muscle on the back of the upper limb of many vertebrates. It is the muscle principally responsible for extension of the elbow joint .-Terminology:...
. In basal Passeri as well as Sylvioidea
Sylvioidea
Sylvioidea is a superfamily of passerine birds. It is one of at least three major clades within the Passerida along with the Muscicapoidea and Passeroidea. It contains about 1300 species including the Old World warblers, Old World babblers, swallows, larks, bulbuls and perhaps the tits...
(which are basal Passerida), there is only one fossa or at most a small second one. In Muscicapoidea and Passeroidea, there always seems to be a second fossa of some size present dorsal of the first. The humerus of Necropsar was said to "differ nowise" from that of Fregilupus or advanced starlings, and in the drawings of the fossils, the double fossa is visible. Judging from the anatomical studies, F. varius – and presumably also N. rodericanus – were probably not basal Passeri and quite likely belonged to the Muscicapoidea, and may indeed have been true starlings.
That Tafforet compared his birds to a thrush
Thrush (bird)
The thrushes, family Turdidae, are a group of passerine birds that occur worldwide.-Characteristics:Thrushes are plump, soft-plumaged, small to medium-sized birds, inhabiting wooded areas, and often feed on the ground or eat small fruit. The smallest thrush may be the Forest Rock-thrush, at and...
and not to some other similarly-sized bird – a quail
Quail
Quail is a collective name for several genera of mid-sized birds generally considered in the order Galliformes. Old World quail are found in the family Phasianidae, while New World quail are found in the family Odontophoridae...
or a grosbeak
Grosbeak
Grosbeak is a form taxon containing several species of seed-eating passerine birds with large beaks. Although they all belong to the superfamily Passeroidea, they are not a natural group but rather a polyphyletic assemblage of distantly related songbirds....
for example – at least suggests that they were rather thrush-like in habitus
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
, and thus probably belonged to the basal Passeri or the Muscicapoidea, and not to the Sylvioidea, let alone the often colourful and sexually dimorphic and/or "finch
Finch
The true finches are passerine birds in the family Fringillidae. They are predominantly seed-eating songbirds. Most are native to the Northern Hemisphere, but one subfamily is endemic to the Neotropics, one to the Hawaiian Islands, and one subfamily – monotypic at genus level – is found...
"-like Passeroidea. Even the latter have, however, evolved an island taxon
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...
with highly unusual feeding habits (the Vampire Finch
Vampire Finch
The Vampire Finch is a small bird native to the Galápagos Islands. It is a very distinct subspecies of the Sharp-beaked Ground Finch endemic to Wolf and Darwin Islands....
Geospiza difficilis septentrionalis). On account of the vocalisations, a placement with the Sturnidae seems indeed more likely than with more basal Passeri: the latter generally have harsh voices, while starlings' songs are indeed composed of a lively, diverse and usually quite musical chatter. It is interesting to note, though, that Tafforet did not compare the vocalizations more explicitly to those of e.g. the European Starling, a very widespread and common bird he almost certainly knew.
The corvid hypothesis advanced by Masauyi Hachisuka can probably be dismissed outright as a somewhat bizarre case of confirmation bias
Confirmation bias
Confirmation bias is a tendency for people to favor information that confirms their preconceptions or hypotheses regardless of whether the information is true.David Perkins, a geneticist, coined the term "myside bias" referring to a preference for "my" side of an issue...
. First, his reasoning is generally tenuous, and even if it is accepted applies equally or more so to the better candidates – e.g. Prionopidae or (if one takes into account adaptation
Adaptation
An adaptation in biology is a trait with a current functional role in the life history of an organism that is maintained and evolved by means of natural selection. An adaptation refers to both the current state of being adapted and to the dynamic evolutionary process that leads to the adaptation....
to the harsh island habitat) Sturnidae. Second, the White-winged Chough
White-winged Chough
The White-winged Chough is one of only two surviving members of the Australian mud-nest builders family, Corcoracidae, and is the only member of the genus Corcorax...
(Corcorax melanorhamphos) is nowadays known neither to be a real chough
Chough
The Red-billed Chough or Chough , Pyrrhocorax pyrrhocorax, is a bird in the crow family; it is one of only two species in the genus Pyrrhocorax...
(Pyrrhocorax) nor a corvid at all, and any perceived similarities of this bird to Tafforet's description cannot be used to argue for a corvid relationship. Third, corvids appear to be of Southeast Asia
Southeast Asia
Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...
n origin, and though they are widely found throughout the Holarctic
Holarctic
The Holarctic ecozone refers to the habitats found throughout the northern continents of the world as a whole. This region is divided into the Palearctic, consisting of Northern Africa and all of Eurasia, with the exception of Southeast Asia and the Indian subcontinent, and the Nearctic,...
and the Americas
Americas
The Americas, or America , are lands in the Western hemisphere, also known as the New World. In English, the plural form the Americas is often used to refer to the landmasses of North America and South America with their associated islands and regions, while the singular form America is primarily...
, they are not very diverse in the regions from where the Mascarenes avifauna originated – and all their species found in southern India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
and southeastern Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
today belong to the crow and raven genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Corvus. Though these are known to be susceptible to island dwarfing and to developing black-and-white plumage they still make an unlikely ancestor for a thrush-like bird with a musical song (a fact that Hachisuka disregarded). Finally, the general improbability of two similarly-sized and somewhat carnivorous passerine
Passerine
A passerine is a bird of the order Passeriformes, which includes more than half of all bird species. Sometimes known as perching birds or, less accurately, as songbirds, the passerines form one of the most diverse terrestrial vertebrate orders: with over 5,000 identified species, it has roughly...
s (as can be deduced from Tafforet's account and the beak
Beak
The beak, bill or rostrum is an external anatomical structure of birds which is used for eating and for grooming, manipulating objects, killing prey, fighting, probing for food, courtship and feeding young...
shape of the fossils) evolving on such a small island with its limited food resources suggests very strongly that Tafforet's bird was the same as the subfossil
Subfossil
Subfossil refers to remains whose fossilization process is not complete, either for lack of time or because the conditions in which they were buried were not optimal for fossilization....
species. This also agrees with the fact that the native passerine birds of Rodrigues had largely non-overlapping ecological niche
Ecological niche
In ecology, a niche is a term describing the relational position of a species or population in its ecosystem to each other; e.g. a dolphin could potentially be in another ecological niche from one that travels in a different pod if the members of these pods utilize significantly different food...
s, and that introductions of passerine birds to the island have met with below-average success even to this day.
Ecology
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
as Tafforet's birds, the absence of another suitable extinct or extant candidate and the severe competitive exclusion on such a resource-poor island like Rodrigues
Rodrigues
Rodrigues is a common surname in the Portuguese language. It was originally a Patronymic, meaning Son of Rodrigo or Son of Rui. The "es" signifies "son of". The name Rodrigo is the Portuguese form of Roderick, meaning "famous power" or "famous ruler", from the Germanic elements "hrod" and "ric" ,...
make it rather likely. No similar bird is known from elsewhere in the Mascarenes, excluding the possibility that the Rodrigues records refer to an ephemeral
Ephemeral
Ephemeral things are transitory, existing only briefly. Typically the term is used to describe objects found in nature, although it can describe a wide range of things....
population of vagrants.
The birds found by Tafforet's party lived on the Île au Mât (today Île Gombrani – sometimes transcribed "Combrani", "Gombranis" or "Mombrani"), an offshore islet of Rodrigues. The bones were found in caves on the Plaine Corail, the island's southwestern calcarenite
Calcarenite
thumb|250px|The [[Pietra di Bismantova]] in central [[Italy]] is an example of calcarenite formation.Calcarenite is a type of limestone that is composed predominately, more than 50 percent, of detrital sand-size , carbonate grains...
limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
plateau east of today's Sir Gaëtan Duval Airport. Île Gombrani is due southeast offshore the Plaine Corail; consequently, the bird must have been fairly numerous at least on the island's southwestern end in former times. The close geographical and ecological association of Tafforet's record and the bones further supports the assumption that all records refer to a single species.
In his report, Tafforet asserted however that he did not encounter his Île Gombrani bird on mainland Rodrigues. He mentions some that were kept by his party, perhaps indicating that the breeding season so coincided with his 9-month visit for easily-caught fledglings to be present. No mention is made of nesting sites on Gombrani, but even 30 years earlier few small birds were found to nest on mainland Rodrigues on account of the rats (see below). While N. rodericanus might have been a ground-nester, this is not so likely; its presumed relatives are generally tree-nesting birds and starlings in particular are often cavity-nesters. There is, however, some woodland on Île Gombrani even today, and the abundant shrubs would have provided ample nesting sites. It is sometimes asserted as certain that the birds kept by Tafforet's party were not adult, but that is conjecture; the original text is ambiguous in that respect. With no report of nesting whatsoever, all that can be said is that Tafforet's encounter probably coincided with the end of the breeding season, after the young had fledged – if N. rodericanus was not easily caught even as adults, which is well possible
Island tameness
Island tameness is the tendency of many populations and species of animals living on isolated islands to lose their wariness of potential predators, particularly of large animals. The term is partly synonymous with ecological naïvete, which also has a wider meaning referring to the loss of...
and was noted in many Mascarene birds (including Fregilupus varius).
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
, today the Plaine Corail is largely pasture
Pasture
Pasture is land used for grazing. Pasture lands in the narrow sense are enclosed tracts of farmland, grazed by domesticated livestock, such as horses, cattle, sheep or swine. The vegetation of tended pasture, forage, consists mainly of grasses, with an interspersion of legumes and other forbs...
and other grassland
Grassland
Grasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...
, with sparse settlement. In the late 19th century it was even less accessible, and had an abundant growth of shrubs and small trees. Much of its original vegetation is shared by the islets offshore western and southern Rodrigues, and this allows to assess what plants grew in the birds' habitat. Among trees and shrubs that might have been used for nesting, native species almost certainly present were the dicots Gastonia rodriguesiana
Gastonia rodriguesiana
Gastonia rodriguesiana is a species of plant in the Araliaceae family. It is endemic to Mauritius.-Source:* Strahm, W. 1998. . Downloaded on 21 August 2007....
(Apiales
Apiales
The Apiales are an order of flowering plants. The families given at right are those recognized in the APG III system. This is typical of the newer classifications, though there is some slight variation, and in particular the Torriceliaceae may be divided...
), Grand Devil's-claws (Pisonia grandis, Caryophyllales
Caryophyllales
Caryophyllales is an order of flowering plants that includes the cacti, carnations, amaranths, ice plants, and many carnivorous plants. Many members are succulent, having fleshy stems or leaves.-Description:...
), Bay Cedar (Suriana maritima, Fabales
Fabales
Fabales is an order of flowering plants. It is included in the rosid group of the eudicots in the Angiosperm Phylogeny Group II classification system...
), Conkerberry (Carissa spinarum) and Antirhea bifida (Gentianales
Gentianales
Gentianales are an order of flowering plants, included within the asterid group of dicotyledons.The circumscription of Gentiales in the Cronquist system included a broadly defined Loganiaceae , Retziaceae, Gentianaceae, Saccifoliaceae, Apocynaceae, and Asclepiadaceae...
), Tree Heliotrope (Heliotropium foertherianum, Lamiales
Lamiales
Lamiales is an order in the asterid group of dicotyledonous flowering plants. It includes approximately 11,000 species divided into about 20 families...
), Ludia mauritiana (Malpighiales
Malpighiales
Malpighiales is one of the largest orders of flowering plants, containing about 16000 species, approximately 7.8% of the eudicots. The order is very diverse and hard to recognize except with molecular phylogenetic evidence. It is not part of any of the classification systems that are based only on...
), Portia Tree
Portia tree
Thespesia populnea, commonly known as the Portia Tree , is species of flowering plant in the mallow family, Malvaceae. It is a small tree or arborescent shrub that has a pantropical distribution, found on coasts around the world. However, the Portia Tree is probably native only to the Old World,...
(Thespesia populnea, Malvales
Malvales
Malvales are an order of flowering plants. As circumscribed by APG II-system, it includes about 6000 species within nine families. The order is placed in the eurosids II, which are part of the eudicots....
), Pemphis acidula (Myrtales
Myrtales
The Myrtales are an order of flowering plants placed as a basal group within the rosid group of dicotyledons...
), Zanthoxylum paniculatum (Sapindales
Sapindales
Sapindales is a botanical name for an order of flowering plants. Well-known members of Sapindales include citrus; maples, horse-chestnuts, lychees and rambutans; mangos and cashews; frankincense and myrrh; mahogany and neem....
), and Lycium mascarenense (Solanales
Solanales
The Solanales are an order of flowering plants, included in the asterid group of dicotyledons. Some older sources used the name Polemoniales for this order....
). Monocots were not certainly present in significant numbers; they might have included the Hurricane Palm (Dictyosperma album var. aureum, Arecales) and Pandanus heterocarpus of the Pandanales
Pandanales
Pandanales is an order of flowering plants, with a pantropical distribution.The APG III system places the Pandanales in the monocots. Both the APG III and APG II systems include five families in this order:* Cyclanthaceae* Pandanaceae* Stemonaceae...
.
With the forest on the Plaine Corail less dense than on the rest of the island, ground cover must have been abundant even when more trees were present. Native herbaceous
Herbaceous
A herbaceous plant is a plant that has leaves and stems that die down at the end of the growing season to the soil level. They have no persistent woody stem above ground...
dicots that provided cover, possibly nesting grounds and maybe supplementary food for the birds include Psiadia rodriguesiana and Rhamphogyne rhynchocarpa (Asterales
Asterales
Asterales is an order of dicotyledonous flowering plants that includes the composite family and its related families.The order is a cosmopolite, and includes mostly herbaceous species, although a small number of trees and shrubs are also present.The Asterales can be characterized on the...
), Aerva congesta and Achyranthes aspera
Achyranthes aspera
Achyranthes aspera is a species of plant in the Amaranthaceae family. It is distributed throughout the tropical world. It can be found in many places growing as an introduced species and a common weed...
var. argentea (Caryophyllales), Hypoestes inconspicua and Nesogenes decumbens (Lamiales), Oldenlandia sieberi var. congesta (Gentianales), and White-edged Morning Glory (Ipomoea nil) and I. rubens (Solanales). Euphorbia thymifolia (Malpighiales) and Ipomoea leucantha might be native, or introduced by early visitors. Poales
Poales
Poales is a large order of flowering plants in the monocotyledons, and includes families of plants such as the grasses, bromeliads, and sedges. Sixteen plant families are currently recognized by botanists to be part of Poales....
of note on Îsle Gombrani and the Plaine Corail are the Tropical Fimbry (Fimbristylis cymosa ssp. cymosa, a sedge
Sedge
- Plants :* Acorus calamus, sweet flag, a plant in the Acoraceae family* Any of the plants in the family Cyperaceae- Animals :* A collective noun for several species of birds, including bitterns, cranes and herons* Sedge-fly, caddisfly- Other uses :...
), and Bermuda Grass (Cynodon dactylon) and Stenotaphrum
Stenotaphrum
Stenotaphrum is a genus of grasses in the family Poaceae. It contains are mere handful of species that are distributed almost world-wide. Most species are found only in the Old World tropics however.- Selected species :...
sp. which are true grasses. The only significant basal tracheophyte in this habitat is the spikemoss
Spikemoss
Selaginella is a genus of plants in the family Selaginellaceae, the spikemosses. Many workers still place the Selaginellales in the class Lycopodiopsida . This group of plants has for years been included in what, for convenience, was called "fern allies". S...
Selaginella balfourii.
Tafforet was not sure why the birds were absent from Rodrigues proper, though he was inclined to attribute it to birds of prey scaring off N. rodericanus. This might refer to migrant
Bird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
falcon
Falcon
A falcon is any species of raptor in the genus Falco. The genus contains 37 species, widely distributed throughout Europe, Asia, and North America....
s (Falco), vagrant Réunion Harrier
Réunion Harrier
The Réunion Harrier or Réunion Marsh Harrier is a bird of prey belonging to the marsh harrier group of harriers. It is now found only on the Indian Ocean island of Réunion where it is known locally as the papangue or pied jaune, although fossil material from Mauritius has been referred to this...
s (Circus maillardi) which were more widespread in the Mascarenes in former times, and of course to the resident Rodrigues Owl
Rodrigues Owl
The Rodrigues Owl , also known as Leguat's Owl or Rodrigues Little Owl, was a small owl. It lived on the Mascarene island of Rodrigues, but it is nowadays extinct. It is part of the genus of Mascarene owls, Mascarenotus...
(Mascarenotus murivorus). The former two, with their presence only temporary, are unlikely to have exerted a marked evolution
Evolution
Evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...
arly pressure on such a sizable endemic resident landbird. The owl on the other hand was not much larger than N. rodericanus and though probably able to subdue them would – in particular its smaller (Morepork-sized) males – have preferred less hefty victims. These were abundant among the native birds, namely the Rodrigues Warbler
Rodrigues Warbler
The Rodrigues Warbler is a species of Old World warbler in the Acrocephalidae family.It is found only on Rodrigues, which belongs to Mauritius....
(Acrocephalus rodericanus) and Rodrigues Fody which both still survive, and perhaps the bulbul
Bulbul
Bulbuls are a family, Pycnonotidae, of medium-sized passerine songbirds. Many forest species are known as greenbuls. The family is distributed across most of Africa and into the Middle East, tropical Asia to Indonesia, and north as far as Japan. A few insular species occur on the tropical islands...
and the "Old World babbler
Old World babbler
The Old World babblers or timaliids are a large family of mostly Old World passerine birds. They are rather diverse in size and coloration, but are characterised by soft fluffy plumage. These are birds of tropical areas, with the greatest variety in Southeast Asia and the Indian Subcontinent...
" which went extinct at an unknown (but probably early) date. Even the small pigeons that used to inhabit Rodrigues would likely have made as good prey to any raptor as did Tafforet's large passerine with its meat-ripping bill. Thus, predation pressure by carnivorous landbirds was probably less significant for N. rodericanus than for the other native passerines. On the other hand, frigatebird
Frigatebird
The frigatebirds are a family, Fregatidae, of seabirds. There are five species in the single genus Fregata. They are also sometimes called Man of War birds or Pirate birds. Since they are related to the pelicans, the term "frigate pelican" is also a name applied to them...
s were earlier noted to frequent the mainland to hunt hatchling
Hatchling
In oviparous biology, a hatchling is the newborn of animals that develop and emerge from within hard-shell eggs. The offspring of birds are often hatched naked and with their eyes closed. The hatchling relies totally on its parents for feeding and warmth. Hatchlings precede nestlings in the chick's...
sea turtle
Sea turtle
Sea turtles are marine reptiles that inhabit all of the world's oceans except the Arctic.-Distribution:...
s and to bully boobies for food at dusk, so it may be those Tafforet had in mind. It is unlikely
Minimum Viable Population
Minimum viable population is a lower bound on the population of a species, such that it can survive in the wild. This term is used in the fields of biology, ecology, and conservation biology...
that the large passerine observed by Tafforet was originally confined to the islet, though seasonally it may have well been so. Overall, the absence of the bird from Rodrigues proper in 1725 is somewhat puzzling, but it may indicate an already-precarious state of the mainland fauna of Rodrigues (see also below).
Feeding
Tafforet also recorded some details on the birds' feeding habits. The food of the adults is described as "nothing else butSeabird
Seabirds are birds that have adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar adaptations...
Beak
The beak, bill or rostrum is an external anatomical structure of birds which is used for eating and for grooming, manipulating objects, killing prey, fighting, probing for food, courtship and feeding young...
in foraging, tearing turtle flesh from the shells and presumably breaking open eggs. The (possibly young) birds kept by his party were given seeds of some tree and chopped-up cooked meat – possibly salt pork
Salt pork
Salt pork or white bacon is salt-cured pork. It is prepared from one of three primal cuts: pork side, pork belly, or fatback. Depending on the cut, respectively, salt pork may be lean, streaky or entirely fatty. Made from the same cuts as bacon, salt pork resembles uncut slab bacon, but is...
, beef
Corned beef
Corned beef is a type of salt-cured beef products present in many beef-eating cultures. The English term is used interchangeably in modernity to refer to three distinct types of cured beef:...
or mutton which were the standard fare for ocean voyages at that time, but perhaps more likely turtle and tortoise meat procured on the island, as his group was effectively stranded on Rodrigues. Tafforet notes that the birds preferred the meat. Since it is unclear what vegetable food precisely Tafforet's party offered the birds, nothing can be said for certain on this. However, it is clear that the birds were at least not exclusively vegetarian. The skull shows an attachment scar above the temporal fossa
Temporal fossa
The temporal fossa is a shallow depression on the side of the skull bounded by the temporal lines and terminating below the level of the zygomatic arch.-Boundaries:...
which indicates it was used for "gaping" and forceful probing as in starlings. The supraoccipital ridge on the skull is quite strongly developed and a biventer muscle attachment in the parietal
Parietal bone
The parietal bones are bones in the human skull which, when joined together, form the sides and roof of the cranium. Each bone is roughly quadrilateral in form, and has two surfaces, four borders, and four angles. It is named from the Latin pariet-, wall....
region below it is conspicuous. This indicates strong neck and jaw muscles, agreeing well with how Tafforet describes the birds' procuring meat from dead turtles. The presumably related Bourbon Crested Starling
Bourbon Crested Starling
The Bourbon Crested Starling , also known as Huppe, Crested Starling, or Réunion Starling is an extinct bird from the family of Sturnidae.-Description:...
(Fregilupus varius) had also notably robust neck and jaw muscles and a good "gaping" ability.
Giant tortoise
Giant tortoises are characteristic reptiles of certain tropical islands. Often reaching enormous size—they can weigh as much as 300 kg and can grow to be 1.3 m long—they live, or lived , in the Seychelles, the Mascarenes and the Galapagos...
s then found on Rodrigues, but perhaps more likely Green Turtles (Chelonia mydas) and Hawksbill Turtle
Hawksbill turtle
The hawksbill sea turtle is a critically endangered sea turtle belonging to the family Cheloniidae. It is the only extant species in its genus. The species has a worldwide distribution, with Atlantic and Pacific subspecies. E. imbricata imbricata is the Atlantic subspecies, while E...
s (Eretmochelys imbricata). The abundant vegetation on Île Gombrani is unlikely to have allowed land tortoises to starve even if they were able to reach the islet (which is not certain). Seabirds whose eggs would have been technically available as food to N. rodericanus were the Brown Noddy
Brown Noddy
The Brown Noddy or Common Noddy is a seabird from the tern family. The largest of the noddies, it can be told from the closely related Black Noddy by its larger size and plumage, which is dark brown rather than black...
(Anous stolidus), Lesser Noddy
Lesser Noddy
The Lesser Noddy , also known as the Sooty Noddy, is a species of tern in the Sternidae family.It is found in Comoros, Kenya, Liberia, Mauritius, Seychelles, South Africa, and United Arab Emirates.- References :...
(A. tenuirostris), White Tern
White Tern
The White Tern is a small seabird found across the tropical oceans of the world. It is sometimes known as the Fairy Tern although this name is potentially confusing as it is the common name of the Fairy Tern Sternula nereis...
(Gygis alba) and Roseate Tern
Roseate Tern
The Roseate Tern is a seabird of the tern family Sternidae. This bird has a number of geographical races, differing mainly in bill colour and minor plumage details....
(Sterna dougallii) which still are found on and around Rodrigues, as well as the Indopacific/Indian Ocean Sooty Tern
Sooty Tern
The Sooty Tern, Onychoprion fuscatus , is a seabird of the tern family . It is a bird of the tropical oceans, breeding on islands throughout the equatorial zone. Colloquially, it is known as the Wideawake Tern or just wideawake...
(Onychoprion fuscatus nubilosus), Abbot's Booby (Papasula abbotti) and the Red-footed Booby
Red-footed Booby
The Red-footed Booby, Sula sula, is a large seabird of the booby family, Sulidae. As suggested by the name, adults always have red feet, but the colour of the plumage varies. They are powerful and agile fliers, but they are clumsy in takeoffs and landings...
(Sula sula) which are now extirpated or uncertain breeders on Rodrigues but were recorded by Tafforet and others. The Great Frigatebird
Great Frigatebird
The Great Frigatebird is a large dispersive seabird in the frigatebird family. Major nesting populations are found in the Pacific and Indian Oceans, as well as a population in the South Atlantic....
(Fregata minor) and perhaps also the Lesser Frigatebird
Lesser Frigatebird
The Lesser Frigatebird, Fregata ariel, is a species of frigatebird.It nests in Australia, among other locations.There is a single record from the Western Palearctic, from Eilat in the Gulf of Aqaba....
(F. ariel) were formerly recorded on Île Gombrani, but only to prey on other birds' eggs; though they bred on nearby Île Frégate, these aggressive birds are unlikely to have their eggs attacked successfully by a passerine. Bourne's Petrel (? Pterodroma sp.) which is entirely extinct, as well as the extirpated Barau's Petrel
Barau's Petrel
Barau's Petrel, Pterodroma baraui is a medium sized gadfly petrel from the family Procellariidae. Its main breeding site is the island of Réunion in the Indian Ocean.-Etymology:...
(P. baraui) and Mascarene Petrel (Pseudobulweria aterrima), seem to have nested near the top of Rodrigues' mountains in burrow
Burrow
A burrow is a hole or tunnel dug into the ground by an animal to create a space suitable for habitation, temporary refuge, or as a byproduct of locomotion. Burrows provide a form of shelter against predation and exposure to the elements, so the burrowing way of life is quite popular among the...
s, and their eggs were thus inaccessible to avian
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
predators. Whether the eggs of the Wedge-tailed Shearwater
Wedge-tailed Shearwater
The Wedge-tailed Shearwater, Puffinus pacificus is a medium-large shearwater in the seabird family Procellariidae. It is one of the shearwater species that is sometimes referred to as a Muttonbird, like the Sooty Shearwater of New Zealand and the Short-tailed Shearwater of Australia...
(Puffinus pacificus), White-tailed Tropicbird
White-tailed Tropicbird
The White-tailed Tropicbird Phaethon lepturus, is a tropicbird, smallest of three closely related seabirds of the tropical oceans and smallest member of the order Phaethontiformes. It occurs in the tropical Atlantic, western Pacific and Indian Oceans...
(Phaeton lepturus) and Red-tailed Tropicbird
Red-tailed Tropicbird
The Red-tailed Tropicbird, Phaethon rubricauda, is a seabird that nests across the Indian and Pacific Oceans. It is the rarest of the tropicbirds, yet is still a widespread bird that is not considered threatened. It nests in colonies on oceanic islands....
(P. rubricauda) – cavity-nesters still breeding on offshore islets of Rodrigues – would have been readily available prey for N. rodericanus is doubtful. With Île Gombrani formerly noted for its abundance of Sooty Terns, it seems that this species yielded most of the "eggs of the fishing birds" Tafforet mentions as staple food of his songbird. Particularly the noddies
Anous
Anous is a genus of birds in the tern family. The genus as presently described consists of three species :* Brown Noddy or Common Noddy, Anous stolidus* Black Noddy, Anous minutus* Lesser Noddy, Anous tenuirostris...
, noted for their extremely docile behaviour, make notable secondary candidates.
But although the seabirds managed to raise three broods in some years at least (as attested by Leguat), given that eggs cannot always have been available and considering that Tafforet does not note his birds to refuse the seeds entirely, N. rodericanus obviously ate some other food. Notable native plants of its habitat, which might have furnished fruits or seeds to complement its diet, are listed above. Apart from the occasional hatchling gecko
Gecko
Geckos are lizards belonging to the infraorder Gekkota, found in warm climates throughout the world. They range from 1.6 cm to 60 cm....
or turtle, invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s probably made up much of the remaining animal food of this bird. The birds are likely to have preyed on the larger-sized of the native arthropod
Arthropod
An arthropod is an invertebrate animal having an exoskeleton , a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...
fauna – spider
Spider
Spiders are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms...
s, millipede
Millipede
Millipedes are arthropods that have two pairs of legs per segment . Each segment that has two pairs of legs is a result of two single segments fused together as one...
s, centipede
Centipede
Centipedes are arthropods belonging to the class Chilopoda of the subphylum Myriapoda. They are elongated metameric animals with one pair of legs per body segment. Despite the name, centipedes can have a varying number of legs from under 20 to over 300. Centipedes have an odd number of pairs of...
s, beetle
Beetle
Coleoptera is an order of insects commonly called beetles. The word "coleoptera" is from the Greek , koleos, "sheath"; and , pteron, "wing", thus "sheathed wing". Coleoptera contains more species than any other order, constituting almost 25% of all known life-forms...
s, butterflies and moth
Moth
A moth is an insect closely related to the butterfly, both being of the order Lepidoptera. Moths form the majority of this order; there are thought to be 150,000 to 250,000 different species of moth , with thousands of species yet to be described...
s – or more likely their caterpillars – Orthoptera
Orthoptera
Orthoptera is an order of insects with paurometabolous or incomplete metamorphosis, including the grasshoppers, crickets and locusts.Many insects in this order produce sound by rubbing their wings against each other or their legs, the wings or legs containing rows of corrugated bumps...
, Hymenoptera
Hymenoptera
Hymenoptera is one of the largest orders of insects, comprising the sawflies, wasps, bees and ants. There are over 130,000 recognized species, with many more remaining to be described. The name refers to the heavy wings of the insects, and is derived from the Ancient Greek ὑμήν : membrane and...
, Hemiptera
Hemiptera
Hemiptera is an order of insects most often known as the true bugs , comprising around 50,000–80,000 species of cicadas, aphids, planthoppers, leafhoppers, shield bugs, and others...
, damselflies
Damselfly
Damselflies are insects in the order Odonata. Damselflies are similar to dragonflies, but the adults can be distinguished by the fact that the wings of most damselflies are held along, and parallel to, the body when at rest...
, the Madagascan Marbled Mantis (Polyspilota aeruginosa), the stick insect Xenomaches incommodus – which is apparently also extinct today –, and presumably the antlion
Antlion
Antlions are a group of insects in the family Myrmeleontidae . The most well-known genus is Myrmeleo. There are about 2,000 species...
Myrmeleon obscurus.
Diptera
Diptera , or true flies, is the order of insects possessing only a single pair of wings on the mesothorax; the metathorax bears a pair of drumstick like structures called the halteres, the remnants of the hind wings. It is a large order, containing an estimated 240,000 species, although under half...
large and lumbering enough to make easy prey for Tafforet's bird seem to have been indigenous to Rodrigues. Terrestrial
Terrestrial animal
Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...
crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s were largely absent too; perhaps only the apparently native woodlouse
Woodlouse
A woodlouse is a crustacean with a rigid, segmented, long exoskeleton and fourteen jointed limbs...
of genus Oniscus
Oniscus
Oniscus is a genus of woodlice. It comprises five species, three of which are confined to northwestern Iberia , one to the Pyrenees , and one of which, O. asellus, is widespread across Europe and has been introduced to the Americas ....
or Porcellio
Porcellio
Porcellio is a genus of woodlice in the family Porcellionidae. These crustaceans are found essentially world-wide. A well-known species is the common rough woodlouse, Porcellio scaber....
would have been available. There were similarly few annelid
Annelid
The annelids , formally called Annelida , are a large phylum of segmented worms, with over 17,000 modern species including ragworms, earthworms and leeches...
s; at least in the woodlands the large earthworm
Earthworm
Earthworm is the common name for the largest members of Oligochaeta in the phylum Annelida. In classical systems they were placed in the order Opisthopora, on the basis of the male pores opening posterior to the female pores, even though the internal male segments are anterior to the female...
Amynthas rodericensis was abundant, but it is unclear whether the birds foraged in such habitat often.
The larger Muscicapoidea – mimid
Mimid
The mimids are the New World family of passerine birds, Mimidae, that includes thrashers, mockingbirds, tremblers, and the New World catbirds...
s, trushes and starling
Starling
Starlings are small to medium-sized passerine birds in the family Sturnidae. The name "Sturnidae" comes from the Latin word for starling, sturnus. Many Asian species, particularly the larger ones, are called mynas, and many African species are known as glossy starlings because of their iridescent...
s – are noted for including an unusual amount of land snail
Land snail
A land snail is any of the many species of snail that live on land, as opposed to those that live in salt water and fresh water. Land snails are terrestrial gastropod mollusks that have shells, It is not always an easy matter to say which species are terrestrial, because some are more or less...
s in their diet; some are expert in cracking open snail shells using their bill and tools such as small stones. Such potential prey was rather abundant on Rodrigues in former times. Namely the genera
Genera
Genera is a commercial operating system and development environment for Lisp machines developed by Symbolics. It is essentially a fork of an earlier operating system originating on the MIT AI Lab's Lisp machines which Symbolics had used in common with LMI and Texas Instruments...
Gonospira
Gonospira
Gonospira is a genus of air-breathing land snails, terrestrial pulmonate gastropod mollusks in the family Streptaxidae.- Distribution :Distribution of the genus Gonospira include:* Mauritius and Rodrigues* Réunion-Species:...
of the Streptaxidae
Streptaxidae
Streptaxidae is a family of air-breathing land snails, terrestrial pulmonate gastropod mollusks in theStylommatophora. Six Streptaxidae subfamilies are accepted in the 2005 taxonomy of the Gastropoda by Bouchet & Rocroi....
and Tropidophora
Tropidophora
Tropidophora is a genus of land snails, terrestrial gastropod mollusks in the family Pomatiidae.- Distribution :These are large, split-sole, operculate snails found in Tanzania, Madagascar, the Mascarenes, the Comoros and South Africa....
of the Pomatiidae
Pomatiidae
The family Pomatiidae is a taxonomic family of small operculate land snails, terrestrial gastropod mollusks that can be found over the warmer parts of the Old World. In the older literature, this family is designated as Pomatiasidae....
have undergone adaptive radiation
Adaptive radiation
In evolutionary biology, adaptive radiation is the evolution of ecological and phenotypic diversity within a rapidly multiplying lineage. Starting with a recent single ancestor, this process results in the speciation and phenotypic adaptation of an array of species exhibiting different...
on the island. Also large enough to furnish food for Tafforet's birds and native to Rodrigues were the possibly extinct Achatinellidae
Achatinellidae
Achatinellidae is a family of tropical air-breathing land snails, terrestrial pulmonate gastropod mollusks in the superfamily Achatinelloidea.- Taxonomy :...
Elasmias jaurffreti
Elasmias jaurffreti
Elasmias jaurffreti is a species of tropical tree-living air-breathing land snail, arboreal pulmonate gastropod mollusk in the family Achatinellidae. This species is endemic to Mauritius....
, the Euconulidae
Euconulidae
Euconulidae is a taxonomic family of minute, air-breathing land snails, terrestrial pulmonate gastropod mollusks or micromollusks. This land snail family is closely allied to the Zonitidae, the glass snails.- Distribution :...
Dancea rodriguezensis
Dancea rodriguezensis
Dancea rodriguezensis is a species of air-breathing land snail, terrestrial pulmonate gastropod mollusk in the family Euconulidae, the hive snails. This species is endemic to Mauritius....
(extant) and Plegma bewsheriana (extinct), an extinct large Pupilla
Pupilla
Pupilla is a genus of minute air-breathing land snails, terrestrial pulmonate gastropod mollusks or micromollusks in the family Pupillidae.The genus Pupilla is known from the Oligocene to the Recent period.-Species:...
sp. (Pupillidae
Pupillidae
Pupillidae is a family of mostly minute, air-breathing, land snails, terrestrial pulmonate gastropod mollusks or micromollusks in the clade Stylommatophora....
), and the and the slug
Slug
Slug is a common name that is normally applied to any gastropod mollusc that lacks a shell, has a very reduced shell, or has a small internal shell...
Vaginula rodericensis (Veronicellidae
Veronicellidae
The Veronicellidae, common name the leatherleaf slugs, are a terrestrial family of pulmonate slugs.This family has no subfamilies ....
). The now-extinct snail species are plentiful in the same caves on the Plaine Corail where the bones of N. rodericanus were found. It has never been studied whether some of the snail shell pieces recovered were smashed by birds; for the time being, it can thus only be noted that none of the other native birds of Rodrigues are known or suspected to have utilized the abundant terrestrial Gastropoda
Gastropoda
The Gastropoda or gastropods, more commonly known as snails and slugs, are a large taxonomic class within the phylum Mollusca. The class Gastropoda includes snails and slugs of all kinds and all sizes from microscopic to quite large...
of the island as food resource.
Extinction
The cause for this intriguing bird's extinction and its date are not known, but can be deduced with fair certainty. With the dating of Tafforet's observation – and the identification of him as the author, which had long eluded researchers –, a terminus post quemTerminus post quem
Terminus post quem and terminus ante quem specify approximate dates for events...
for the extinction is established. It is more difficult to assess final extinction dates, as some remnant population may linger on for a long time (see also Lazarus taxon
Lazarus taxon
In paleontology, a Lazarus taxon is a taxon that disappears from one or more periods of the fossil record, only to appear again later. The term refers to the account in the Gospel of John, in which Jesus raised Lazarus from the dead...
). However, Rodrigues is a small island, and was often visited throughout the 18th century to capture tortoise
Tortoise
Tortoises are a family of land-dwelling reptiles of the order of turtles . Like their marine cousins, the sea turtles, tortoises are shielded from predators by a shell. The top part of the shell is the carapace, the underside is the plastron, and the two are connected by the bridge. The tortoise...
s and sea turtle
Sea turtle
Sea turtles are marine reptiles that inhabit all of the world's oceans except the Arctic.-Distribution:...
s (until Cylindraspis peltastes
Cylindraspis peltastes
The Domed Rodrigues giant tortoise was a species of giant tortoise in the Testudinidae family. It was endemic to Rodrigues. It appears to have become extinct around 1800....
and C. vosmaeri
Cylindraspis vosmaeri
The Saddle-backed Rodrigues giant tortoise was a species of tortoise in the Testudinidae family. It was endemic to Rodrigues. The introduction of predators and hunting pressures are believed to have caused the extinction of this species.-References:* World Conservation Monitoring Centre 1996. . ...
went extinct about 1800, too). By 1740, a major trade in these had developed, as their relatives
Cylindraspis
Cylindraspis is a genus of recently extinct giant tortoises. All of its species lived in the Mascarene Islands in the Indian Ocean and all are now extinct due to hunting and introduction of non-native predators. These giant tortoises were very large and slow, thus making them easy game. The...
on the other Mascarene islands were already gone or nearly so. The island must thus have been surveyed to a considerable degree by the mid-18th century. When A. G. Pingré
Alexandre Guy Pingré
Alexandre Guy Pingré was a French astronomer, priest, and naval geographer.He was born in Paris, France, and was educated at Senlis, where he became professor of theology in 1735. At an early age he had developed an interest in astronomy, and in 1749 he was appointed professor of astronomy at the...
during the French
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
1761 Transit of Venus expedition observed the seabird colonies of Île Gombrani in 1761, he found them still healthy; no trace of Tafforet's bird was noted, however, while the burgeoning Testudines-based economy of the island offered little other food than tortoise dishes in the nearly 15 weeks he stayed. Neither did Philibert Marragon see the birds some decades later; he already remarked upon the tortoises' impending extinction though. Quite likely, N. rodericanus became extinct within one decade of 1740.
That Tafforet did not encounter it on the main island, with a population essentially confined to one or a few islets and vulnerable to any stochastic
Stochastic
Stochastic refers to systems whose behaviour is intrinsically non-deterministic. A stochastic process is one whose behavior is non-deterministic, in that a system's subsequent state is determined both by the process's predictable actions and by a random element. However, according to M. Kac and E...
catastrophe such as a tsunami
Tsunami
A tsunami is a series of water waves caused by the displacement of a large volume of a body of water, typically an ocean or a large lake...
or Mauritius cyclone, is suggestive of an extinction shortly thereafter. It is uncertain, however, whether his survey of the inhospitable Plaine Corail region was thorough enough to find any birds remaining there. François Leguat
François Leguat
François Leguat was a French explorer and naturalist.Leguat was a French Huguenot originating from the Province of Bresse, now part of the department of Ain, who fled to Holland in 1689 after the revocation of the Edict of Nantes in 1685...
, who was marooned with his companions in 1691–1693 on the north coast where now is Port Mathurin
Port Mathurin
The village of Port Mathurin serves as the capital of the island of Rodrigues, a dependency of Mauritius. It lies on the north coast of the Indian-Ocean island and functions as the administrative, judicial and economic centre of Rodrigues. As the name suggests, it also operates the main harbour of...
, does not explicitly mention the birds either in his extensive writings. Though his party visited most accessible parts of the island, he does not mention the striking karst
KARST
Kilometer-square Area Radio Synthesis Telescope is a Chinese telescope project to which FAST is a forerunner. KARST is a set of large spherical reflectors on karst landforms, which are bowlshaped limestone sinkholes named after the Kras region in Slovenia and Northern Italy. It will consist of...
-like landscape of the Plaine Corail – a major tourist attraction today –, and probably only saw it from a distance. He discusses a low-lying plain of several square kilometers, but as he extols the richness of its deep soil and ample tree-cover the La Ferme region – extensively logged
Logging
Logging is the cutting, skidding, on-site processing, and loading of trees or logs onto trucks.In forestry, the term logging is sometimes used in a narrow sense concerning the logistics of moving wood from the stump to somewhere outside the forest, usually a sawmill or a lumber yard...
nowadays, but then still pristine –, where several small rivers have deposited abundant sediment
Sediment
Sediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....
s, makes a far better match for this locality.
This may be taken to suggest that the birds were in fact confined to the island's southwest, and perhaps only common on offshore islets, as early as 1690. Of the latter, Leguat visited several, almost certainly including Île aux Diamants and the sandy islet next to Port Mathurin's harbour, perhaps Île aux Fous north of these at the reef edge, as well as some well-wooded islets which were most likely Île aux Cocos
Île aux Cocos
Île aux Cocos is a small island lying west of Rodrigues in the Indian Ocean. It is a nature reserve known for colonies of noddies, lesser noddies and fairy terns....
and Île aux Sables northwest of the mainland. He described the multitude of birds nesting on the latter. Gombrani is hard to reach on foot without crossing the Plaine Corail with its numerous sinkhole
Sinkhole
A sinkhole, also known as a sink, shake hole, swallow hole, swallet, doline or cenote, is a natural depression or hole in the Earth's surface caused by karst processes — the chemical dissolution of carbonate rocks or suffosion processes for example in sandstone...
s and cave
Cave
A cave or cavern is a natural underground space large enough for a human to enter. The term applies to natural cavities some part of which is in total darkness. The word cave also includes smaller spaces like rock shelters, sea caves, and grottos.Speleology is the science of exploration and study...
s (neither of which is mentioned in Leguat's report), and though having some trees is at least today mainly covered in lower vegetation. Also, Leguat does not discuss the Rodrigues Warbler
Rodrigues Warbler
The Rodrigues Warbler is a species of Old World warbler in the Acrocephalidae family.It is found only on Rodrigues, which belongs to Mauritius....
(Acrocephalus rodericanus), which must in his time have inhabited the mainland where it is still present today (albeit precariously rare), and thus there are some places on the mainland he did not visit.
He mentions seeing the Rodrigues Fody
Rodrigues Fody
The Rodrigues Fody is a rare species of bird in the weaver family. It is endemic to Rodrigues, an island of Mauritius. It is classified by BirdLife International as being vulnerable. It is also on the United States' Endangered Species List with an endangered status.This bird is 12 to 13...
(Foudia flavicans) but no other songbirds except "very few swallow
Swallow
The swallows and martins are a group of passerine birds in the family Hirundinidae which are characterised by their adaptation to aerial feeding...
s" – most likely vagrant Mascarene Martin
Mascarene Martin
The Mascarene Martin is a species of bird in the Hirundinidae family.It is found in Comoros, Madagascar, Malawi, Mauritius, Mozambique, Réunion, Seychelles, and Tanzania.-References:...
s (Phedina borbonica). These resemble the grey-brown Crag Martin
Crag Martin
The Eurasian Crag Martin or just Crag Martin is a small passerine bird in the swallow family. It is about 14 cm long with ash-brown upperparts and paler underparts, and a short, square tail that has distinctive white patches on most of its feathers. It breeds in the mountains of southern...
(Ptyonoprogne rupestris) that is not rare in France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
. However, with the colour pattern described by Tafforet, N. rodericanus may well have resembled the black-and-white House Martin
House Martin
The Common House Martin , sometimes called the Northern House Martin or, particularly in Europe, just House Martin, is a migratory passerine bird of the swallow family which breeds in Europe, north Africa and temperate Asia; and winters in sub-Saharan Africa and tropical Asia...
(Delichon urbicum) – the most common swallow in European cities and towns – if seen in flight from below. Thus, it is not entirely certain that Leguat never encountered the "starling". What can be said is that the absence of Tafforet's bird in Leguat's detailed testimony is best explained by its general absence from the Port Mathurin region – and perhaps the rest of the island, or most of it – in 1691–1693.
In general, the cause of the birds' disappearance was almost certainly some introduced species, rather than habitat destruction
Habitat destruction
Habitat destruction is the process in which natural habitat is rendered functionally unable to support the species present. In this process, the organisms that previously used the site are displaced or destroyed, reducing biodiversity. Habitat destruction by human activity mainly for the purpose of...
or overhunting, as the reports of the first long-term inhabitants contain no mention of the bird any more. Feral goat
Feral goat
The feral goat is the domestic goat when it has become established in the wild. Feral goats occur in Australia, New Zealand, Ireland, Great Britain, Hawaii, the Galapagos and in many other parts of the world...
s and other likely candidates were only present after Leguat's visit, but he noted the large numbers of rat
Rat
Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus, and the brown rat, Rattus norvegicus...
s, for which he had no satisfying explanation (but see below). The initial rat population has been identified from old bones as Black Rat
Black Rat
The black rat is a common long-tailed rodent of the genus Rattus in the subfamily Murinae . The species originated in tropical Asia and spread through the Near East in Roman times before reaching Europe by the 1st century and spreading with Europeans across the world.-Taxonomy:The black rat was...
s (Rattus rattus), though starting in the late 18th century these were probably replaced by the Brown Rat
Brown Rat
The brown rat, common rat, sewer rat, Hanover rat, Norway rat, Brown Norway rat, Norwegian rat, or wharf rat is one of the best known and most common rats....
(R. norvegicus) which predominates today. As a tree-climbing predator of nestlings and egg
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
s, the Black Rat would certainly represent a major threat to any insular endemic songbird. Species likely to have carried avian diseases to Rodrigues were not introduced until after the disappearance of N. rodericanus, and thus it seems as good as certain that Tafforet's bird was killed off by the Black Rat, succumbing when these finally reached the offshore islets. At Leguat's time, he noted that the islands he visited seemed rat-free, and he reasoned that the Rodrigues Grey Pigeon
Rodrigues Grey Pigeon
The Rodrigues Grey Pigeon is an extinct species of pigeon formerly endemic to the Mascarene island of Rodrigues. It is known from a subfossil sternum and some other bones, and the descriptions of Leguat and Julien Tafforet . It was a bird the size of a Tambourine Dove and colored slate grey...
("Alectroenas" rodericana) nested only there because on the mainland rats were already too numerous.
It is not clear when Black Rats arrived on the island. Leguat's report is the first comprehensive one, and he mentions the main island overrun with them – and he does not mention the bulbul
Bulbul
Bulbuls are a family, Pycnonotidae, of medium-sized passerine songbirds. Many forest species are known as greenbuls. The family is distributed across most of Africa and into the Middle East, tropical Asia to Indonesia, and north as far as Japan. A few insular species occur on the tropical islands...
and presumed Old World babbler
Old World babbler
The Old World babblers or timaliids are a large family of mostly Old World passerine birds. They are rather diverse in size and coloration, but are characterised by soft fluffy plumage. These are birds of tropical areas, with the greatest variety in Southeast Asia and the Indian Subcontinent...
that once lived there. While Arabic, Swahili
Swahili language
Swahili or Kiswahili is a Bantu language spoken by various ethnic groups that inhabit several large stretches of the Mozambique Channel coastline from northern Kenya to northern Mozambique, including the Comoro Islands. It is also spoken by ethnic minority groups in Somalia...
and maybe Pandyan sailors knew Rodrigues as (probably) Diva Harab ("Desert Island") before the 16th century, the Late Medieval voyages of the Indian Ocean
Indian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
trade seem quite long ago even for the extreme overpopulation
Overpopulation
Overpopulation is a condition where an organism's numbers exceed the carrying capacity of its habitat. The term often refers to the relationship between the human population and its environment, the Earth...
of rats observed by Leguat to develop. The island was relocated by Portugal
Portugal
Portugal , officially the Portuguese Republic is a country situated in southwestern Europe on the Iberian Peninsula. Portugal is the westernmost country of Europe, and is bordered by the Atlantic Ocean to the West and South and by Spain to the North and East. The Atlantic archipelagos of the...
in 1507 and visited (mainly by Dutch
Netherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...
ships) occasionally from 1601 on; Leguat mentions inscriptions cut by Dutch sailors in the bark
Bark
Bark is the outermost layers of stems and roots of woody plants. Plants with bark include trees, woody vines and shrubs. Bark refers to all the tissues outside of the vascular cambium and is a nontechnical term. It overlays the wood and consists of the inner bark and the outer bark. The inner...
of several trees.
With N. rodericanus as rare as to be overlooked for two years in 1693, still extant in 1725, but extinct shortly thereafter, and some mainland birds apparently already extinct by 1691, it was probably roughly between 1550 and 1650 that the Black Rat settled Rodrigues.