Checker-throated Stipplethroat Epinecrophylla fulviventris Scientific name definitions

Most species in the genus Epinecrophylla are similar to one another: small brown antwrens, the males of which have throats with a black and white "checkered" pattern. The Checker-throated Antwren is the only member of the genus that occurs west of the Andes; this species is found from Honduras south to northern Colombia and to western Ecuador. Singles, pairs, or family groups forage in the under- and midstory of lowland forest and adjacent second growth, usually as members of mixed species flocks. As is typical of all species of Epinecrophylla, the Checker-throated Antwren searches for arthropods that are hidden in curled, dead leaves that are trapped in vine tangles and other sites above the ground. The nest is a deep purse-like cup, usually located within a few meters of the ground. The clutch is two. Juvenile Checker-throated Antwrens follow the parents for up to six months after fledging.

10–11 cm; 8·5–11·5 g. Male has grey-brown crown and upperparts, reddish remiges and tail; wing-coverts blackish-brown, more olive-brown in Magdalena Valley in Colombia (“salmoni”, but apparently intergrading with other birds in N), coverts with large yellow-ochre tips; ear-coverts grey; throat black with large white spots; breast grey, rest of underparts are mostly brownish-buff, darker posteriorly; iris golden, becoming rich chocolate-brown in older birds. Female differs from male in having side of head and throat brownish-buff. Juvenile has grey iris, becoming pale yellow in first-year plumage.

Caribbean slope from extreme SE Honduras S to W Panama, thence both slopes E from Veraguas, and Colombia (Pacific slope, base of N end of Andes E to Santander, and Magdalena Valley S to Antioquia and Boyacá) and W Ecuador (S to El Oro).

Understory of lowland and foothill evergreen forest and adjacent tall second-growth woodland; mostly below 1100 m, locally to 2000 m in Colombia. Favors, or perhaps requires, areas with abundant vine tangles supporting high density of aerial leaf litter.

Resident.

Feeds on various insects, particularly cockroaches (Blattidae), crickets (Gryllidae) and katydids (Tettigoniidae), and spiders. Forages as closely associated pair-members, individuals, or family groups, 0·5–25 m above ground; in 126 observations in a study in Panama, mean height was 10·5 m; other fieldwork in Panama/Costa Rica suggests that most foraging is at 1–8 m. Food obtained almost exclusively from recesses of curled, arboreal dead leaves; in Panama study, 98% of its foraging time was spent in searching aerial leaf litter. Usually with mixed-species flocks of insectivores; studies on Barro Colorado I (Panama) indicate that territories are highly stable and typically coincide with those of Microrhopias quixensis, or often of Myrmotherula axillaris, which then travel in same flocks, and that the species co-defend their territories. In intraspecific displays, males face each other c. 30 cm apart, lower the head, fluff out back plumage, and pivot from side to side, vocalizing incessantly. Forages mostly in vine tangles and along slender branches of understory trees, or on understory palms; progresses rapidly by short hops, often hitching from side to side, ignoring intervening live foliage and systematically pausing to inspect single hanging dead leaves and also dead-leaf clusters trapped in vines, in branches and in tops of small palms. At higher elevations, also occasionally inspects leaf litter lodged in small epiphytes, and moss tangles along trunks of trees. Gleans prey from smaller dead leaves mostly by reaching up with neck and legs extended, or by hanging head downwards from adjacent perches; from larger leaves by hanging acrobatically like a tit (Paridae) from the margins (often upside-down) or bottom of the leaf itself, or by perching atop it; spends 5–15 seconds, and sometimes 1 minute or longer, in rummaging audibly in a single leaf or cluster, probing by delicately inserting the bill, sometimes the entire head, into curls and crevices. When larger prey item obtained, usually hops or flies to a nearby horizontal perch and bashes it forcefully against the branch, sometimes for up to a minute, until it is subdued. Owing to lengthy searching of leaves and protracted time spent in handling large prey, this species is often left behind after more active flock mates have moved on. Occasionally visits army-ant swarms for short periods, rarely sallying to ground or air to catch escaping insects.

Loudsong a variable series of abrupt, countable, almost stacatto notes (e.g. 11 notes, 2·5 seconds), variable in pace, pitch and intensity, but often accelerates and intensifies initially and decelerates and dies off slightly at end; same note delivered much more rapidly in intraspecific agonistic display. Calls include a moderately long sibilant note and a rattle.

Mar–Aug in Costa Rica; in Panama, nests found in all months except Dec and Apr but concentrated in rainy season, and newly fledged young recorded on Barro Colorado I in Nov–Mar; a nest in Dec in Colombia. Nest a deep (15 cm), pensile pouch with oblique opening at top, composed of fine blackish-brown fungal filaments and rootlets, supporting thick layer of dead leaves, lined with fine fibres, c. 0·4–2 m (occasionally to 8 m) above ground in terminal fork of thin, drooping twig of understory sapling, shrub or vine tangle; multiple nests often built by same pair. Normal clutch 2 eggs, white or cream-colored, with reddish-brown, purplish-chestnut, and pale lilac blotches, fine spots and scrawls mostly concentrated in wreath around larger end; incubation by both parents, only by female at night, period 18–20 days; juveniles in Panama continued to follow parents closely in mixed-species flocks, occasionally begging, for at least 4–6 months after fledging; courtship and nest-building commenced after young from previous year had dispersed. Of 26 and 51 nests in Panama in two successive years, success was 30.8% and 27.5%, respectively.

Not globally threatened. Fairly common throughout its range. This includes a number of protected areas, e.g. Braulio Carrillo National Park and La Selva Biological Reserve, in Costa Rica, Soberanía and Darién National Parks and Comarca Kuna Yala Indigenous Reserve, in Panama, Los Katíos National Park, in Colombia, and Río Palenque Science Centre and the Manglares-Churute Ecological Reserve, in Ecuador. Continued protection of the forests in these and other existing reserves should ensure the maintenance of viable populations of this species.