Euler's Flycatcher
Encyclopedia
Euler's Flycatcher, Lathrotriccus euleri, is a small passerine
bird
in the tyrant flycatcher
family
. It breeds in South America
east of the Andes
from Colombia
and Venezuela
south to Bolivia
and Argentina
, and on the islands of Trinidad
and formerly also Grenada
(see below). This species is named for the Swiss ornithologist Carl Euler
.
In appearance, it closely resembles the Empidonax
flycatchers, and was formerly placed in that genus, but differs in anatomical and molecular characters. Euler's Flycatcher is on average 12.7 centimetres (5 in) long and weighs 10–11 g (0.35273962105112–0.388013583156232 oz). The upperparts are olive-brown with darker brown wings and two dull buff wing bars. The throat breast is grey, the breast is brown, and the abdomen is pale yellow. There is a white eyering, but no supercilium
. Sexes are similar. There are other races, differing in the tone of the upperpart or underpart colour. The call is a loud hoarse chee-chi-wi-wi-wi.
This species is found in the lower and middle levels of forests. Euler's Flycatchers are inconspicuous birds, tending to keep to undergrowth perches from which they sally forth to catch insect
s; they are also capable of hovering flight to pick off prey from plants, but use it far less often.
In subtropical montane forest in the south of its range, it breeds in the rainy summer months, with peak nesting activity in late October to November and extending to January-February. The open cup nest is made of grass, leaves and plant fibre and placed in a tree fork. It is usually located a few meters above ground, but may be right up in the tree's crown.
The typical clutch is 2-3 white eggs, which are marked with reddish brown mostly at the larger end, weigh about 1.7 gram (0.0599657355786903 oz) each and measure roughly 18 by 13.5 mm (0.708661417322835 by 0.531496062992126 in). Only the female incubates, and she will every now and then leave the nest for various reasons. When on the nest, the male provisions her with food. At about 20–25 °C (68–77 F) ambient temperature, the young hatch after 16–18 days, and fledge
after about 15 days. They are being fed by both parents, and older nestlings have a voracious appetite. As they near fledging, one can find a parent arriving with new food every few minutes. Brood loss due to predation was found to be moderate to light in the Southern Andean Yungas
.
It is often fairly common, and on a global scale it is not considered threatened. However, the Grenadan Euler's Flycatcher (L. e. flaviventris) has not been recorded since the early 1950s, and is likely extinct. The reasons for this are insufficiently known, but probably related to habitat destruction
and possibly introduced predators. A junior synonym of flaviventris is johnstoni, but the latter was used when Euler's Flycatcher was placed in the genus Empidonax, as flaviventris is preoccupied in that genus by the Yellow-bellied Flycatcher
(E. flaviventris).
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...
bird
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...
in the tyrant flycatcher
Tyrant flycatcher
The tyrant flycatchers are a family of passerine birds which occur throughout North and South America. They are considered the largest family of birds on Earth, with more than 400 species. They are the most diverse avian family in every country in the Americas, except for the United States and...
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...
. It breeds in South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
east of the Andes
Andes
The Andes is the world's longest continental mountain range. It is a continual range of highlands along the western coast of South America. This range is about long, about to wide , and of an average height of about .Along its length, the Andes is split into several ranges, which are separated...
from Colombia
Colombia
Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...
and Venezuela
Venezuela
Venezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...
south to Bolivia
Bolivia
Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...
and Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
, and on the islands of Trinidad
Trinidad
Trinidad is the larger and more populous of the two major islands and numerous landforms which make up the island nation of Trinidad and Tobago. It is the southernmost island in the Caribbean and lies just off the northeastern coast of Venezuela. With an area of it is also the fifth largest in...
and formerly also Grenada
Grenada
Grenada is an island country and Commonwealth Realm consisting of the island of Grenada and six smaller islands at the southern end of the Grenadines in the southeastern Caribbean Sea...
(see below). This species is named for the Swiss ornithologist Carl Euler
Carl Euler
Carl Hieronymus Euler was a Swiss farmer and amateur ornithologist.Euler was born in Basel. In 1853 he travelled to Rio de Janeiro and bought a farm near Cantagalo. He became Swiss vice-consul, and in his spare time collected birds and studied their habits. His findings were published in the...
.
In appearance, it closely resembles the Empidonax
Empidonax
The genus Empidonax is a group of small insect-eating passerine birds in the tyrant flycatcher family, the Tyrannidae.Most of these birds are remarkably similar in plumage: olive on the upper parts with light underparts, eye rings and wing bars...
flycatchers, and was formerly placed in that genus, but differs in anatomical and molecular characters. Euler's Flycatcher is on average 12.7 centimetres (5 in) long and weighs 10–11 g (0.35273962105112–0.388013583156232 oz). The upperparts are olive-brown with darker brown wings and two dull buff wing bars. The throat breast is grey, the breast is brown, and the abdomen is pale yellow. There is a white eyering, but no supercilium
Supercilium
The supercilium is a plumage feature found on the heads of some bird species. It is a stripe which runs from the base of the bird's beak above its eye, finishing somewhere towards the rear of the bird's head. Also known as an "eyebrow", it is distinct from the eyestripe, which is a line which runs...
. Sexes are similar. There are other races, differing in the tone of the upperpart or underpart colour. The call is a loud hoarse chee-chi-wi-wi-wi.
This species is found in the lower and middle levels of forests. Euler's Flycatchers are inconspicuous birds, tending to keep to undergrowth perches from which they sally forth to catch insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s; they are also capable of hovering flight to pick off prey from plants, but use it far less often.
In subtropical montane forest in the south of its range, it breeds in the rainy summer months, with peak nesting activity in late October to November and extending to January-February. The open cup nest is made of grass, leaves and plant fibre and placed in a tree fork. It is usually located a few meters above ground, but may be right up in the tree's crown.
The typical clutch is 2-3 white eggs, which are marked with reddish brown mostly at the larger end, weigh about 1.7 gram (0.0599657355786903 oz) each and measure roughly 18 by 13.5 mm (0.708661417322835 by 0.531496062992126 in). Only the female incubates, and she will every now and then leave the nest for various reasons. When on the nest, the male provisions her with food. At about 20–25 °C (68–77 F) ambient temperature, the young hatch after 16–18 days, and fledge
Fledge
Fledge is the stage in a young bird's life when the feathers and wing muscles are sufficiently developed for flight. It also describes the act of a chick's parents raising it to a fully grown state...
after about 15 days. They are being fed by both parents, and older nestlings have a voracious appetite. As they near fledging, one can find a parent arriving with new food every few minutes. Brood loss due to predation was found to be moderate to light in the Southern Andean Yungas
Yungas
The Yungas is a stretch of forest along the eastern slope of the Andes Mountains from southeastern Peru through central Bolivia. It is a transitional zone between the Andean highlands and the eastern forests. Like the surrounding areas, it has characteristics of the Neotropic ecozone...
.
It is often fairly common, and on a global scale it is not considered threatened. However, the Grenadan Euler's Flycatcher (L. e. flaviventris) has not been recorded since the early 1950s, and is likely extinct. The reasons for this are insufficiently known, but probably related to 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...
and possibly introduced predators. A junior synonym of flaviventris is johnstoni, but the latter was used when Euler's Flycatcher was placed in the genus Empidonax, as flaviventris is preoccupied in that genus by the Yellow-bellied Flycatcher
Yellow-bellied Flycatcher
The Yellow-bellied Flycatcher is a small insect-eating bird of the tyrant flycatcher family.Adults have brownish-olive upperparts, darker on the wings and tail, with yellowish underparts; they have a white eye ring, white wing bars, a small bill and a short tail...
(E. flaviventris).
Further reading
- ffrench, Richard; O'Neill, John Patton & Eckelberry, Don R. (1991): A guide to the birds of Trinidad and Tobago (2nd edition). Comstock Publishing, Ithaca, N.Y. ISBN 0-8014-9792-2
- Hilty, Steven L. (2003): Birds of Venezuela. Christopher HelmHelm Identification GuidesThe Helm Identification Guides are a series of books that identify groups of birds. The series include two types of guides, those that are:* Taxonomic, dealing with a particular family of birds on a worldwide scale—most early Helm Guides were this type, as well as many more-recent ones,...
, London. ISBN 0-7136-6418-5