Grallaria oneilli Chesser & Isler, 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 : 18-19

Grallaria oneilli Chesser & Isler , new species

O’Neill’s Antpitta

Includes population designated obscura 2 in the analysis.

Diagnosis. Upperparts reddish yellow-brown; underparts paler, grading to whitish on center of belly and undertail coverts; pale buff eye-ring. Vocalizations differ from all taxa in the G. rufula complex except G. gravesi and G. obscura by their frequency modulated notes. Long songs of G. oneilli ( Fig. 11 ) are faster paced than long songs of G. gravesi and G. obscura . Intervals between notes of the long song of G. oneilli are near-constant in duration, whereas intervals of long songs of G. gravesi increase and then decrease in duration, and those of G. obscura increase in duration throughout. Two additional characters distinguish vocalizations of G. oneilli from G. obscura , although not from G. gravesi . Notes in the second half of long songs of G. gravesi and G. oneilli rise in frequency, whereas notes of G. obscura decline in frequency. In addition, initial notes of short songs of G. gravesi and G. oneilli come to a single frequency peak, whereas those of G. obscura include three peaks (rarely two).

Distribution. East Andean slope in Huánuco and Pasco, Peru, south of the Río Huallaga and north of the Río Perené, 2750–3700 m.

Holotype. Louisiana State University Museum of Natural Science ( LSUMZ) 113581, tissue number LSUMZ B– 3510. Adult male found near timberline by MLI and P. R. Isler, mist-netted and prepared as a study skin by J. P. O’Neill on 21 June 1983 at Bosque Potrero, 14 km W Panao, Huánuco, Peru (76° 05’ W, 09°59’ S, elevation 3345 m).

Description of holotype. Adult male. Overall plumage of upperparts, including crown, auriculars, nape, back, and uppertail coverts reddish yellow-brown (7.5YR 4/6), shading to color of underparts in malar area; eye-ring pale buff. Rectrices and remiges reddish yellow-brown (7.5YR 4/6), primaries edged paler. Throat and breast light reddish yellow-brown (7.5YR 6/8), paler on belly with center of belly whitish; undertail coverts color of belly mixed with pale yellowish-buff (2.5Y 8/4); flank coloration intermediate between upperparts and breast. Throat and breast substantially paler than that of its sister species, G. gravesi and G. obscura . Testes 2 mm; skull ossified; mass 38 g; moderate fat; no body molt; stomach packed with insect parts. Soft part colors: iris dark brown, base of mandible pinkish, feet and tarsi medium gray.

Measurements of holotype. Bill length 11.54 mm, bill width 4.76 mm, wing length 80.97 mm, tail length 46.66 mm, tarsus length 42.00 mm.

Paratopotype. LSUMZ 113582 (male).

Paratypes. LSUMZ 128539 (male) , LSUMZ 128541 (female) , FMNH 66252 (female) , AMNH 174092 (female immature) (specimen photographs App. 6, Fig. A 25) .

Etymology. The scientific and English names honor Dr. John P. O’Neill who collected the type specimen. John O’Neill has dedicated his career to the exploration of ornithologically unknown regions in Peru, extending knowledge of poorly known species, discovering new taxa, and training generations of students in the art and science of ornithological field work. Newly described species in this paper reflect the modern renewal of ornithological collecting in the Andes, of which John O’Neill was a pioneer.

Remarks. See remarks provided for G. gravesi and G. obscura .

Figures

FIGURE 11. Songs of Grallaria oneilli: (A) long song, Millpo, Pasco, Peru (Schulenberg ML40152); (B) short song, PN Yanachaga-Chemillén, Pasco (Vellinga XC62929).