Euler's flycatcher (''Lathrotriccus euleri'') is a small

passerine A passerine () is any bird of the order Passeriformes (; from Latin 'sparrow' and '-shaped'), which includes more than half of all bird species. Sometimes known as perching birds, passerines are distinguished from other orders of birds by t ...

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...

in the tyrant flycatcher

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

. It breeds in

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

east of the

Andes The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...

from

Colombia Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Car ...

and

Venezuela Venezuela (; ), officially the Bolivarian Republic of Venezuela ( es, link=no, República Bolivariana de Venezuela), is a country on the northern coast of South America, consisting of a continental landmass and many islands and islets in th ...

south to

Bolivia , image_flag = Bandera de Bolivia (Estado).svg , flag_alt = Horizontal tricolor (red, yellow, and green from top to bottom) with the coat of arms of Bolivia in the center , flag_alt2 = 7 × 7 square p ...

and

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

, and on the islands of

Trinidad Trinidad is the larger and more populous of the two major islands of Trinidad and Tobago. The island lies off the northeastern coast of Venezuela and sits on the continental shelf of South America. It is often referred to as the southernmos ...

and formerly also

Grenada Grenada ( ; Grenadian Creole French: ) is an island country in the West Indies in the Caribbean Sea at the southern end of the Grenadines island chain. Grenada consists of the island of Grenada itself, two smaller islands, Carriacou and Pe ...

(see below). This species is named for the Swiss

ornithologist Ornithology is a branch of zoology that concerns the "methodological study and consequent knowledge of birds with all that relates to them." Several aspects of ornithology differ from related disciplines, due partly to the high visibility and th ...

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 long and weighs . 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 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.Dunn and Alderfer (2006), p. 10 Also ...

. 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 Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...

s; they are also capable of hovering flight to pick off prey from plants, but use it far less often. In

subtropical The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Geographical z ...

montane forest Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial f ...

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 each and measure roughly . 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 ambient temperature, the young hatch after 16–18 days, and

fledge Fledging is the stage in a flying animal's life between hatching or birth and becoming capable of flight. This term is most frequently applied to birds, but is also used for bats. For altricial birds, those that spend more time in vulnerable c ...

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 Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the ...

was found to be moderate to light in the Southern Andean

Yungas The Yungas (Aymara ''yunka'' warm or temperate Andes or earth, Quechua ''yunka'' warm area on the slopes of the Andes) is a bioregion of a narrow band of forest along the eastern slope of the Andes Mountains from Peru and Bolivia, and extends into ...

. 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 Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

. The reasons for this are insufficiently known, but probably related to

habitat destruction Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

and possibly introduced

predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

s. A

junior synonym The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linna ...

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 The yellow-bellied flycatcher (''Empidonax flaviventris'') is a small insect-eating bird of the tyrant flycatcher family. Description Adults have greenish upperparts and yellowish underparts (especially on the throat), with a dusky wash on the ...

(''E. flaviventris'').

References

Further reading