Grallaria occabambae marcapatensis, 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 : 23-24

Grallaria occabambae marcapatensis, Isler & Chesser , new subspecies

Includes the population designated occabambae 1b in the analysis.

Diagnosis. Plumage similar to nominate except upperparts tend to be lighter and brighter, and undertail coverts similar in color to belly but paler. Short songs of this subspecies are three-noted rather than two-noted as in the nominate form, and the average pace of long songs is significantly slower, although ranges of measurements overlap.

Distribution. Endemic to Peru in Cusco east of the Río Yanatili valley and between the Río Tambo to the north and the Río Marcapata to the south, 2450–3650 m.

Holotype. Field Museum of Natural History ( FMNH) 222152. Adult female collected by C. Kalinowski on 26 July 1953 at Amacho, Cusco, Peru (near Marcapata, 70° 55’ W, 13° 30’ S, elevation 2750 m).

Description of holotype. Adult female. Overall plumage of upperparts, including crown, auriculars, nape, back, and uppertail coverts, strong reddish yellow-brown (7.5YR 4/6); malar tending to breast color. Rectrices and remiges dark reddish-yellow-brown (7.5YR 4/4), primaries edged paler. Throat, breast and belly light reddish yellow-brown (7.5YR 6/8) with pale feather edgings. Undertail coverts light reddish yellow-brown (7.5YR 7/8).

Measurements of holotype. Bill length 10.91, bill width 4.55, wing length 77.67, tail length 41.91, tarsus length 39.78.

Paratypes. LSUMZ 78575 (male), MSB 34460 (male), FMNH 429996 (female) (specimen photographs App. 6, Fig. A30).

Etymology. The subspecific name refers to the Marcapata district, where the type specimen was collected.

Remarks. Consistent differences in the number of notes in short songs and the generally slower pace of long songs of G. o. marcapatensis indicate that the two subspecies of G. occabambae are on independent evolutionary paths. However, these vocal differences are insufficient to support species status under our criteria, a conclusion supported by the small mtDNA genetic distance (~1%) between them. Also, possible differences in coloration require substantiation with larger samples.