Phylloscartes Ventralis

The mottle-cheeked tyrannulet (''Phylloscartes ventralis'') is a generally common, small species of bird in the family Tyrannidae, the tyrant flycatchers. It is found in Argentina, Bolivia, Brazil, Paraguay, Peru, and Uruguay.

Taxonomy and systematics

Some early twentieth century authors considered the mottle-cheeked tyrannulet and what are now the Panama tyrannulet (''P. flavovirens'') and olive-green tyrannulet (''P. virescens'') as conspecific. The three are now treated by many authors as a superspecies.Remsen, J. V., Jr., J. I. Areta, E. Bonaccorso, S. Claramunt, G. Del-Rio, A. Jaramillo, D. F. Lane, M. B. Robbins, F. G. Stiles, and K. J. Zimmer. Version 18 November 2024. A classification of the bird species of South America. American Ornithological Society. https://www.museum.lsu.edu/~Remsen/SACCBaseline.htm retrieved November 26, 2024

The mottle-cheeked tyrannulet has three subspecies, the nominate ''P. v. ventralis'' (Temminck, 1824), ''P. v. angustirostris'' (d'Orbigny & Lafresnaye, 1837), and ''P. v. tucumanus'' ( Zimmer, JT, 1940). Some authors believe that the "recognition of subspecies may be unwarranted".Fitzpatrick, J. W. (2023). Mottle-cheeked Tyrannulet (''Phylloscartes ventralis''), version 1.1. In Birds of the World (B. K. Keeney, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.moctyr2.01.1 retrieved December 19, 2024

Description

The mottle-cheeked tyrannulet is about long and weighs about . The sexes have the same plumage, and the subspecies also have essentially the same plumage as well. Adults have a short thin whitish supercilium, an indistinct broken whitish eye-ring, a dusky line through the eye, a wide whitish and dusky crescent below the eye, a dusky "moustache", and the eponymous whitish and dusky mottled cheeks. Their crown, nape, back, and rump are dark olive. Their wings are dusky with bright olive-yellow outer webs at the base of the flight feathers. Their wing coverts have pale yellow to yellow tips that form two wing bars. Their tail is dusky with bright olive-yellow outer webs at the base of the feathers. Their chin and upper throat are whitish. The rest of their underparts vary from olive grayish to mostly yellowish with faint olive markings. Their belly and undertail coverts can be a paler yellow. Both sexes of all subspecies have a dark brown iris, a long, flat, pointed black bill with a pinkish to yellowish base to the mandible, and slate to bluish gray legs and feet.

Distribution and habitat

The mottle-cheeked tyrannulet has a disjunct distribution, with each subspecies separate from the others. Subspecies ''P. v. angustirostris'' forms one population. It is found on the eastern slope of the Andes from northern Peru's Amazonas Department south through the country into Bolivia's La Paz and Cochabamba departments. ''P. v. tucumanus'' is found in northwestern Argentina from Jujuy Province south into Tucumán and Catamarca provinces. The nominate ''P. v. ventralis'' has the largest range. It is found from Minas Gerais state in southeastern Brazil southwest through Mato Grosso do Sul into eastern Paraguay and south throughout Uruguay and northeastern Argentina as far as Entre Ríos Province.

In the Andes the mottle-cheeked tyrannulet primarily inhabits montane evergreen forest and to a lesser extent higher ridgetop cloudforest and lower tropical forest. In elevation it ranges between . In Brazil, Paraguay, Uruguay, and northeastern Argentina it occurs in montane forest and also tropical forest, gallery forest, and temperate forest dominated by ''Araucaria'' or ''Podocarpus''. There it is mostly found below but locally ranges somewhat higher.

Behavior

Movement

All populations of the mottle-cheeked tyrannulet are year-round residents.

Feeding

The mottle-cheeked tyrannulet feeds mostly on arthropods and includes a few fruits in its diet. It forages actively, usually from the forest's mid-story to its canopy but sometimes lower in dense understory. It perches horizontally, sometimes with its tail slightly cocked up, and makes short sallies to grab or hover-glean prey from leaves and twigs. Its wings make a whir during the sallies. It typically forages singly or in pairs and sometimes joins mixed-species feeding flocks.

Breeding

The mottle-cheeked tyrannulet's breeding season has not been fully defined. In Brazil it breeds between August and December and in Argentina from October to December. In Peru its season includes November. A nest of subspecies ''P. v. tucumanus'' was a ball made from plant fibers, dead leaves, lichen, and moss; it had a side entrance with a small "roof". A nest of ''P. v. angustirostris'' was similar but made entirely of "Spanish moss" (''Tillandsia usneoides''). Nests have been noted as suspended from a horizontal branch between above the ground. The clutch is three eggs and the female alone incubates. The incubation period is about 18 days and fledging occurs about 17 days after hatch. Both parents provision the nestlings and remove fecal sacs.

Vocalization

The mottle-cheeked tyrannulet's song has been described as "a descending, accelerating rattle ''tchep tik tik-teer'r'r'r'' and its call as "weak, sneezy, metallic ''tchee'' or ''tchep'' notes". Another description of is song is a "very high, mainly level pitched, twittering trill, which starts hesitantly, accelerates, then slows down at the end with some very sharp, very high notes".

Status

The IUCN has assessed the mottle-cheeked tyrannulet as being of Least Concern. It has a very large range; its population size is not known and is believed to be decreasing. No immediate threats have been identified. It is considered fairly common to common.

References

{{Taxonbar, from=Q1271621

mottle-cheeked tyrannulet
Birds of the Atlantic Forest
Birds of Brazil
Birds of Uruguay
Birds of the Yungas
mottle-cheeked tyrannulet
Taxonomy articles created by Polbot