Mountain elaenia
The mountain elaenia is a small passerine bird in subfamily Elaeniinae of family Tyrannidae, the tyrant flycatchers. It is found in Colombia, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, Panama, and Venezuela.
Taxonomy and systematics
The mountain elaenia has these four subspecies:E. f. ultima Griscom, 1935E. f. frantzii Lawrence, 1865E. f. browni Bangs, 1898E. f. pudica Sclater, PL, 1871The three subspecies other than the nominate E. f. frantzii have bounced around as subspecies of other elaenia species before reaching their current status. However, vocal studies published in 2016 suggest that the species has only two subspecies, with ultima being absorbed into frantzii and browni being absorbed into pudica. There are further suggestions that the two putative subspecies should be treated as separate species.
At least one early twentieth century publication treated the mountain elaenia and highland elaenia as conspecific but by the middle of the century that treatment had been abandoned, and early twenty-first century genetic studies showed that they are not closely related.
The mountain elaenia's specific epithet celebrates the German physician and naturalist Alexander von Frantzius, who collected the type specimen.
Description
The mountain elaenia is long and weighs about. It is a small to medium size elaenia with a rounded crest. The sexes have the same plumage. Adults of the nominate subspecies have a brownish olive head with lighter cheeks, a thin very pale olive eyering, and a mostly hidden white patch on the crown. Their upperparts are grayish olive. Their wings are mostly dusky with pale olive or olive-yellow edges on the flight feathers. The tips of their wing coverts are yellowish olive and show as two bars on the closed wing. Their tail is grayish brown with pale olive-green feather edges. Their chin, throat, upper breast, and flanks are pale yellowish olive, and their lower breast, belly, and undertail coverts pale straw yellowish. Juveniles are similar to adults but browner above and paler below.Subspecies E. f. ultima has browner upperparts and darker, more olivaceous, underparts than the nominate. E. f. pudica is smaller than the nominate and has darker upperparts and paler underparts. E. f. browni is smaller than pudica but with paler, more greenish olive, upperparts. Both sexes of all subspecies have a brown iris, a dark brown maxilla, an orange mandible with a dark brown tip, and dark brown legs and feet.
Distribution and habitat
The mountain elaenia has a disjunct distribution. The subspecies are found thus:E. f. ultima: from Chiapas in southern Mexico south through Guatemala, El Salvador, and Honduras into northwestern Nicaragua E. f. frantzii: southern Nicaragua and after a gap from western Costa Rica to central PanamaE. f. browni: the isolated Sierra Nevada de Santa Marta in northern Colombia and the separate Serranía del Perijá that straddles the Colombia-Venezuela borderE. f. pudica: Colombia's Western and [Cordillera Cordillera Central (Colombia)|Central (Colombia)|Central] Andes, the Andes of western Venezuela, and the Venezuelan Coastal RangeOlder field guides and other publications do not include Chiapas in the mountain elaenia's range; the species was not confirmed there until 2016. Similarly, earlier range maps do not extend to central Panama, where there are records starting in the mid 2010s.
The two Central American subspecies of the mountain elaenia primarily inhabit cloudforest but also occur in semi-open pine-oak forest and the edges of denser forest. In South America the species primarily inhabits open woodlands, scrublands, and pastures with scattered trees, and some coffee plantations and cloudforest in Colombia. In elevation it in occurs between in Central America, between in Colombia, between in the Venezuelan Andes, and between in the Serranía del Perijá.