Grallaria ayacuchensis Hosner, Robbins, Isler, & Chesser, 2020

Isler, Morton L., Chesser, Terry, Robbins, Mark B., Cuervo, Andrés M., Cadena, Carlos Daniel & Hosner, Peter A., 2020, Taxonomic evaluation of the Grallaria rufula (Rufous Antpitta) complex (Aves: Passeriformes: Grallariidae) distinguishes sixteen species, Zootaxa 4817 (1), pp. 1-74 : 21-22

Grallaria ayacuchensis Hosner, Robbins, Isler, & Chesser , new species

Ayacucho Antpitta

Includes population designated blakei 3 in the analysis.

Diagnosis. Upperparts dark reddish yellow-brown; anterior underparts paler grading to light buff on lower belly. Trilled long songs in combination with short songs consisting of a regularly repeated unmodulated note distinguish G. ayacuchensis ( Fig. 14 ) from all other populations except G. centralis . Vocal differences between G. ayacuchensis and G. centralis include short song note shape (rounded in G. centralis and downslurred in G. ayacuchensis ) and pattern of change in duration of long song notes (notes lengthen or remain constant in G. centralis and shorten in G. ayacuchensis ). The pace of long songs of G. ayacuchensis is faster than that of G. centralis , and although ranges of values did not overlap, means did not differ significantly, presumably because of small sample sizes.

Distribution. Endemic to Peru on east Andean slope in Ayacucho west of the Río Apurímac between the Río

Mantaro and Río Pampas, 2500–3700 m.

Holotype. Centro de Ornitología y Biodiversidad ( CORBIDI) AV-KVG166. Adult male shot by P. A. Hosner in Chusquea thicket in secondary forest, and prepared as a study skin by Karen Verde-Guerra, on 22 September 2012 at Chupón, Dpto. Ayacucho, Peru (13° 16’ S, 73°30’ W, elevation 3300 m). Voice recorded ( ML 186926).

Description of holotype. Adult male. Overall plumage of upperparts dark reddish yellow-brown (7.5YR 4/4), with throat and breast grading toward yellowish red-brown (5YR 5/8). Crown, auriculars, nape, back, rump, wing, uppertail coverts, and rectrices dark reddish yellow-brown (7.5YR 4/4). Remiges dark reddish yellow-brown (7.5YR 4/4) with the inner vane of each feather slightly duskier. Orbital, lores, throat, breast, side of breast, and upper flanks yellowish red-brown (5YR 5/8), grading to light buff on lower belly. Some feathers on belly have faint pale neutral gray mottling. Lower flanks grading to dark reddish yellow-brown (7.5YR 4/4), undertail coverts pinkish white (7.5YR 8/4). Testes 8 x 4 mm; skull 50% pneumatized; no bursa of Fabricius; stomach: insects; moderate fat, wt: 48.4 g; heavy contour feather molt. Iris dark brown, legs dusky gray, bill black.

Measurements of holotype. Bill length 12.7 mm, wing length 83.7 mm, tail length 41.3 mm, tarsus length 46.3 mm.

Paratopotypes. KU 132736 (male), KU 132701 (male), CORBIDI Av-MBR 8329 (male), CORBIDI Av- PAH1242 (male).

Paratypes. KU 119996 (female), AMNH 820776 (male) (specimen photographs App. 6, Fig. A28).

Etymology. The scientific and English names reflect its restricted known distribution on the humid eastern slopes of the Department of Ayacucho, Peru.

Remarks. May also occur in adjacent northeastern Huancavelica. See remarks for G. centralis . Holotype also cataloged as University of Kansas Biodiversity Institute (KU) 122629, tissue number 29375.

Figures

FIGURE 14. Songs of Grallaria ayacuchensis: (A) long song, Chupón, Ayacucho, Peru (Hosner ML186919); (B) short song, Chupón (Robbins ML173831).