Clarion Island
Encyclopedia
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Revillagigedo Islands
The Revillagigedo Islands or Revillagigedo Archipelago are a group of four volcanic islands in the Pacific Ocean, known for their unique ecosystem...
, 314 kilometres (195.1 mi) west of Socorro Island
Socorro Island
Socorro Island is a small volcanic island in the Revillagigedo Islands, a Mexican possession lying some 600 kilometers off the country's western coast at 18°48'N, 110°59'W. The size is 16.5 by 11.5 km, with an area of 132 km².- Geology :...
and over 700 kilometres (435 mi) from the Mexican mainland and an area 19.8 kilometres (12.3 mi)². It has three prominent peaks. The westernmost and tallest peak, Monte Gallegos, is 335 metres (1,099.1 ft) high. The central peak is called Monte de la Marina, 280 metres (918.6 ft), and the eastern peak Pico de la Tienda 292 metres (958 ft). The coasts are backed by perpendicular cliffs, 24 to 183 m (78.7 to 600.4 ) high, with the exception of the middle part of the southern coast in the vicinity of Bahia Azufre (Sulphur Bay), which is the location of a small military garrison manned by 9 men.
Two small and at least temporarily brackish pools are the only source of freshwater
Freshwater
Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...
; even these may dry up in summers with little rain.
History
Clarión Island was discovered in late 1542 by the Spanish navigator Ruy López de VillalobosRuy López de Villalobos
Ruy López de Villalobos was a Spanish explorer who sailed the Pacific from Mexico to establish a permanent foothold for Spain in the East Indies, which was near the Line of Demarcation between Spain and Portugal according to the Treaty of Saragossa in 1529...
. But with the exception of a possible re-sighting of the Revillagigedos by Juan Fernández de Ladrillero prior to 1574 and a short-lived residence by the adventurer Martín Yáñez de Armida on that island he later re-named Socorro (1606), the archipelago was neglected by the Spaniards and Joris van Spilbergen
Joris van Spilbergen
Joris van Spilbergen was a Dutch naval officer of the 17th century.His first major expedition was in 1596, when he sailed to Africa....
's sighting of the whole group in December 1615 seems not to have been noted in Spain or its American colonies.
Clarion was sighted again by the English privateer George Shelvocke
George Shelvocke
Captain George Shelvocke was an English privateer who wrote a famous 1723 book based on his exploits, A Voyage Round the World By Way of The Great South Sea....
on the Speedwell, August 21, 1721.
The name of the island goes back to the American brig Clarion, Capt. Henry Gyzelaar, who was engaged in the North Pacific trade around 1820.
Ecology
As the topographyTopography
Topography is the study of Earth's surface shape and features or those ofplanets, moons, and asteroids...
of Clarión lacks any prominent peaks that could induce rains like Cerro Evermann on Socorro Island
Socorro Island
Socorro Island is a small volcanic island in the Revillagigedo Islands, a Mexican possession lying some 600 kilometers off the country's western coast at 18°48'N, 110°59'W. The size is 16.5 by 11.5 km, with an area of 132 km².- Geology :...
, the island is semiarid to arid
Arid
A region is said to be arid when it is characterized by a severe lack of available water, to the extent of hindering or even preventing the growth and development of plant and animal life...
all over. Consequently, the whole of the island is covered in shrubland
Shrubland
Shrubland, scrubland, scrub or brush is a plant community characterized by vegetation dominated by shrubs, often also including grasses, herbs, and geophytes. Shrubland may either occur naturally or be the result of human activity...
, 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...
and Opuntia
Opuntia
Opuntia, also known as nopales or paddle cactus , is a genus in the cactus family, Cactaceae.Currently, only prickly pears are included in this genus of about 200 species distributed throughout most of the Americas. Chollas are now separated into the genus Cylindropuntia, which some still consider...
cacti
Cacti
-See also:* RRDtool The underlying software upon which Cacti is built* MRTG The original Multi Router Traffic Grapher from which RRDtool was "extracted".* Munin -External links:******...
. Far away from land, endemic taxa are fewer than on Socorro but like there mainly consist of landbirds and plants. Rabbit
Rabbit
Rabbits are small mammals in the family Leporidae of the order Lagomorpha, found in several parts of the world...
s and feral
Feral
A feral organism is one that has changed from being domesticated to being wild or untamed. In the case of plants it is a movement from cultivated to uncultivated or controlled to volunteer. The introduction of feral animals or plants to their non-native regions, like any introduced species, may...
sheep are found on the island and have caused serious harm to the local vegetation; pigs introduced in 1979 have caused harm to the local fauna
Fauna
Fauna or faunæ is all of the animal life of any particular region or time. The corresponding term for plants is flora.Zoologists and paleontologists use fauna to refer to a typical collection of animals found in a specific time or place, e.g. the "Sonoran Desert fauna" or the "Burgess shale fauna"...
.. Native vertebrate
Vertebrate
Vertebrates are animals that are members of the subphylum Vertebrata . Vertebrates are the largest group of chordates, with currently about 58,000 species described. Vertebrates include the jawless fishes, bony fishes, sharks and rays, amphibians, reptiles, mammals, and birds...
s - except birds - are limited to one snake and one iguanid
Iguania
Iguania is the suborder of Squamata that contains the iguanas, chameleons, agamids, and "New World lizards" such as anoles and Phrynosomatidae...
lizard, both endemic.
A few seabird
Seabird
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...
species breed on Clarión or formerly did so. The island is near the north(east)ern limit of the breeding range of several of these, but their continued presence needs confirmation:
- Nazca BoobyNazca BoobyThe Nazca Booby, Sula granti, is a booby which is found in the eastern Pacific Ocean, namely on the Galápagos Islands where it can be seen by eco-tourists, and on Clipperton Island...
, Sula granti - East Pacific Red-footed BoobyRed-footed BoobyThe 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 websteri - a doubtfully distinct subspeciesSubspeciesSubspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one... - East Pacific Great FrigatebirdGreat FrigatebirdThe 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 ridgwayi - breeding suspected but not verified; a doubtfully distinct subspecies
For reasons not fully known, Clarión seems to be more attractive to shorebirds and other vagrant or 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...
birds than Socorro; perhaps this is due to the presence of Red-tailed Hawk
Red-tailed Hawk
The Red-tailed Hawk is a bird of prey, one of three species colloquially known in the United States as the "chickenhawk," though it rarely preys on standard sized chickens. It breeds throughout most of North America, from western Alaska and northern Canada to as far south as Panama and the West...
s on the latter island. Great Blue Heron
Great Blue Heron
The Great Blue Heron is a large wading bird in the heron family Ardeidae, common near the shores of open water and in wetlands over most of North and Central America as well as the West Indies and the Galápagos Islands. It is a rare vagrant to Europe, with records from Spain, the Azores and England...
, Snowy Egret
Snowy Egret
The Snowy Egret is a small white heron. It is the American counterpart to the very similar Old World Little Egret, which has established a foothold in the Bahamas....
, White-faced Ibis
White-faced Ibis
The White-faced Ibis is a wading bird in the ibis family Threskiornithidae.This species breeds colonially in marshes, usually nesting in bushes or low trees. Its breeding range extends from the western USA south through Mexico, as well as from southeastern Brazil and southeastern Bolivia south to...
, Pacific
Pacific Golden Plover
The Pacific Golden Plover is a medium-sized plover.The 23–26 cm long breeding adult is spotted gold and black on the crown, back and wings. Its face and neck are black with a white border and it has a black breast and a dark rump. The legs are black...
and possibly American Golden Plover
American Golden Plover
The American Golden Plover is a medium-sized plover.Adults are spotted gold and black on the crown, back and wings. Their face and neck are black with a white border; they have a black breast and a dark rump. The legs are black....
, Spotted Sandpiper
Spotted Sandpiper
The Spotted Sandpiper is a small shorebird, 18–20 cm long. Together with its sister species, the Common Sandpiper they make up the genus Actitis...
, Wandering Tattler
Wandering Tattler
The Wandering Tattler, Tringa incana , is a medium-sized wading bird. It is similar in appearance to the closely related Gray-tailed Tattler, T. brevipes...
, Ruddy Turnstone
Ruddy Turnstone
The Ruddy Turnstone is a small wading bird, one of two species of turnstone in the genus Arenaria. It is now classified in the sandpiper family Scolopacidae but was formerly sometimes placed in the plover family Charadriidae...
, Black-necked Stilt
Black-necked Stilt
The Black-necked Stilt is a locally abundant shorebird of American wetlands and coastlines. It is found from the coastal areas of California through much of the interior western United States and along the Gulf of Mexico as far east as Florida, then south through Central America and the Caribbean...
, Western Gull
Western Gull
The Western Gull, Larus occidentalis, is a large white-headed gull that lives on the western coast of North America. It was previously considered conspecific, the same species, with the Yellow-footed Gull of the Gulf of California...
and Barn Swallow
Barn Swallow
The Barn Swallow is the most widespread species of swallow in the world. It is a distinctive passerine bird with blue upperparts, a long, deeply forked tail and curved, pointed wings. It is found in Europe, Asia, Africa and the Americas...
are examples of the species that can be encountered on Clarión with some regularity; most of the shorebirds congregate in the sheltered shallows of Sulphur Bay. Others, such as Blue-winged Teal
Blue-winged Teal
The Blue-winged Teal is a small dabbling duck from North America.-Description:The Blue-winged Teal is long, with a wingspan of , and a weight of . The adult male has a greyish blue head with a white facial crescent, a light brown body with a white patch near the rear and a black tail. The adult...
, Western Sandpiper
Western Sandpiper
The Western Sandpiper, Calidris or Erolia mauri, is a small shorebird.Adults have dark legs and a short thin dark bill, thinner at the tip. The body is brown on top and white underneath. They are reddish-brown on the crown. This bird can be difficult to distinguish from other similar tiny...
, Least Sandpiper
Least Sandpiper
The Least Sandpiper is the smallest shorebird.This species has greenish legs and a short thin dark bill. Breeding adults are brown with dark brown streaks on top and white underneath. They have a light line above the eye and a dark crown. In winter, Least Sandpipers are grey above...
, Short-eared Owl
Short-eared Owl
The Short-eared Owl is a species of typical owl . In Scotland this species of owl is often referred to as a cataface, grass owl or short-horned hootlet. Owls belonging to genus Asio are known as the eared owls, as they have tufts of feathers resembling mammalian ears. These "ear" tufts may or may...
, Belted Kingfisher
Belted Kingfisher
The Belted Kingfisher is a large, conspicuous water kingfisher, the only member of that group commonly found in the northern United States and Canada. It is depicted on the 1986 series Canadian $5 note. All kingfishers were formerly placed in one family, Alcedinidae, but recent research suggests...
, Northern Mockingbird
Northern Mockingbird
The Northern Mockingbird, Mimus polyglottos, is the only mockingbird commonly found in North America. This species was first described by Linnaeus in his Systema naturae in 1758 as Turdus polyglottos....
and Brown-headed Cowbird
Brown-headed Cowbird
The Brown-headed Cowbird is a small brood parasitic icterid of temperate to subtropical North America. They are permanent residents in the southern parts of their range; northern birds migrate to the southern United States and Mexico in winter, returning to their summer habitat around March or...
have only been recorded on very few occasions, sometimes only once.
Endemic animals
- Clarión Burrowing OwlBurrowing OwlThe Burrowing Owl is a tiny but long-legged owl found throughout open landscapes of North and South America. Burrowing Owls can be found in grasslands, rangelands, agricultural areas, deserts, or any other open dry area with low vegetation. They nest and roost in burrows, such as those excavated...
, Athene cunicularia rostrata - Clarión WrenClarión WrenThe Clarión Wren is a species of bird in the Troglodytidae family.It is endemic to Clarión Island off Pacific Mexico....
, Troglodytes tanneri (VulnerableVulnerable speciesOn 30 January 2010, the IUCN Red List of Threatened Species identified 9694 Vulnerable species, subspecies and varieties, stocks and sub-populations.-References:...
) - Clarión Mourning DoveMourning DoveThe Mourning Dove is a member of the dove family . The bird is also called the Turtle Dove or the American Mourning Dove or Rain Dove, and formerly was known as the Carolina Pigeon or Carolina Turtledove. It is one of the most abundant and widespread of all North American birds...
, Zenaida macroura clarionensis - Clarion Island Whipsnake, Masticophis anthonyi
- Urosaurus clarionensis
In addition, the local population of the Western Raven (Corvus corax sinuatus or C. sinuatus) was formerly considered a distinct subspecies clarionensis, but this is not usually accepted at present. It can be expected that this question will soon be resolved as there is currently renewed interest in the phylogeny of the Common/Western/Chihuahuan Raven
Chihuahuan Raven
The Chihuahuan Raven , is a species of bird in the family Corvidae that is native to the United States and Mexico. It was formerly known as the American White-necked Raven, and has the proportions of a Common Raven with a heavy bill, but is about the same size as a Carrion Crow, or slightly larger...
s. If the Revillagigedos population is indeed distinct, it might an endemic of Clarión as the only other local subpopulation, on San Benedicto, was destroyed by a volcanic eruption on August 1, 1952; on the other hand, mainland birds have sometimes been assigned to clarionensis also.
The Clarión population of the Critically Endangered
Critically Endangered
Critically Endangered is the highest risk category assigned by the IUCN Red List for wild species. Critically Endangered means that a species' numbers have decreased, or will decrease, by 80% within three generations....
Townsend's Shearwater
Townsend's Shearwater
Townsend's Shearwater, Puffinus auricularis, is a rare seabird of the tropics from the family Procellariidae.Its relationships are unresolved. Its closest relatives are probably, but not certainly, the Hawaiian Shearwater and possibly the Manx Shearwater...
(Puffinus auricularis) was probably extirpated in 1988 due to the feral pigs' depredations on the young and nesting birds.
Plants
Endemic plant taxa of Clarión are:- Aristida tenuifolia
- Ipomoea halierca
- Physalis clarionensis
Brickellia peninsularis var. amphithalassaBulbostylis nesiotica, Cheilanthes peninsularis var. insularis, Cyperus duripes, Euphorbia anthonyi, Nicotiana stocktonii, Perityle socorrosensis, Spermacoce nesiotica and Zapoteca formosa ssp. rosei are Revillagigedo endemics which Clarión shares with either San Benedicto or Socorro. Whether Teucrium townsendii var. townsendii is the same plant as on San Benedicto is not conclusively determined.
There has not been recent dedicated research on the impact the sheep and rabbits had on the local flora
Flora
Flora is the plant life occurring in a particular region or time, generally the naturally occurring or indigenous—native plant life. The corresponding term for animals is fauna.-Etymology:...
. While no plants seem to have gone extinct on the other Revillagigedo Islands, Clarión is one most heavily affected by introduced herbivore
Herbivore
Herbivores are organisms that are anatomically and physiologically adapted to eat plant-based foods. Herbivory is a form of consumption in which an organism principally eats autotrophs such as plants, algae and photosynthesizing bacteria. More generally, organisms that feed on autotrophs in...
s.