Acre Tody-Tyrant Hemitriccus cohnhafti Scientific name definitions

Acre Tody-Tyrant is one of the least known species of Neotropical birds: it was not detected by ornithologists until as recently as 2009, and was not described as a species until 2013. This small tyrant flycatcher first was observed in southwestern Brazil, in the state of Acre, but as could have been expected, it soon was observed in adjoining southeastern Peru, and almost surely occurs as well in adjacent northwestern Bolivia. Acre Tody-Tyrant occupies thickets of bamboo (Guadua), second growth, and the edge of humid lowland forest, especially in upland areas. The behavior of Acre Tody-Tyrant is similar to that of many other members of the genus, foraging for insects in the understory with short sallies, mostly directed to leaf surfaces. The plumage of Acre Tody-Tyrant is characteristically drab, mostly olive above, with two narrow, bronzy wingbars, and pale olive on the throat and breast, with creamy yellowish streaks. Acre Tody-Tyrant is most similar to Snethlage's Tody-Tyrant (Hemitriccus minor) and to Yungas Tody-Tyrant (Hemitriccus spodiops), but is distinguished from the former by the buff lores and supraloral region, and its more distinct wingbars; and from the latter by having shorter crown feathers, the crown is concolor with the back (rather than being duller and more brownish), and in having more conspicuous wingbars. Otherwise the natural history of Acre Tody-Tyrant is almost completely unknown.

SW Amazonian Brazil (Acre), Peru (Madre de Dios) (2 Harvey, M.G., Lane, D.F., Hite, J., Terrill, R.S., Figueroa Ramírez, S., Smith, B.T., Klicka, J. and Vargas Campos, W. (2014). Notes on bird species in bamboo in northern Madre de Dios, Peru including the first Peruvian record of Acre Tody-Tyrant (Hemitriccus cohnhafti). Occ. Pap. Mus. Nat. Sci. Louisiana State Univ. 81: 1–38. Close ) and probably adjacent Bolivia (Pando).

Inhabits second-growth forest on well‐drained, nutrient‐poor soils in upland areas, dominated in some areas by dead or dying, often collapsed, Guadua bamboo with little or no overstorey; in Acre, SW Brazil, such forests have a canopy height of no more than c. 12 m (occasionally as low as 5 m), albeit with scattered, taller emergents, many vines and slender leguminous saplings, and dense patches of Arum plants, but perhaps fewer patches of bamboo than in neighbouring Peru. Lowlands below c. 300 m. The species appears to be absent from nearby seasonally flooded (várzea) forest and taller upland terra firme forest (the latter being occupied by H. flammulatus and Lophotriccus eulophotes).

Arthropods, but no further details of diet. Forages primarily in the understorey, mostly at 1–4 m above ground, gleaning prey from the undersides of live foliage in short (c. 1 m) upward sallies. No evidence that it associates with mixed-species flocks while feeding.

Song a trill, usually without introductory notes, uttered at regular but typically widely spaced intervals, although occasionally 2–4 trills are given in quick succession, especially in response to playback, when this species’ song occasionally becomes a much longer trill (of up to 38 notes). Compared to that of closely related H. spodiops, song is typically shorter (0·22 seconds vs 0·64 seconds), of fewer notes (mean c. 8 vs c. 33), achieves a much lower peak frequency (mean 2·29 kHz vs 2·91 kHz) and is slower-paced (mean 36·5 notes/second vs c. 51 notes/second), although there is overlap in the last-named character; even longer songs of the type described in response to playback remain of shorter duration (up to 0·47 seconds) and lower peak frequency (mean 2·25 kHz), but faster pace (mean 64·6 notes/second) than those of H. spodiops. Gives various single-note “skep” or “keek” calls, sometimes as a precursor to song bouts (frequency 2·5–3·2 kHz), or lower-frequency “kup” calls (c. 2 kHz), and these may be strung together in tighter series, e.g. “kup keek” or “kup keek keek”; the structurally complex “kreeeep” call of H. spodiops, which comprises 9–10 closely spaced notes that ascend in pitch then decline, and is very similar to common vocalization of Lophotriccus pileatus, apparently has no analogy within the repertoire of the present species.

Not globally threatened. Currently considered Near Threatened. Known from scarcely a handful of localities. Population unknown but believed to be decreasing, as its entire range (estimated at 15,200 km²) lies within the so-called Arc of Deforestation covering many parts of S (& E) Amazonia. Consequently, the species’ distribution is being impacted as a result of habitat loss for ranching (extensively so around the type locality), is potentially becoming more fragmented and, with further information, H. cohnhafti may warrant uplisting to Vulnerable in the future. Nevertheless, the species occupies at least some secondary habitats and may prove to be significantly more widespread than currently known in Guadua‐dominated and possibly other successional habitats on upland terraces throughout the region of Guadua‐dominated forest in SW Amazonia, including suitable areas in neighbouring extreme NW Bolivia.