Yungas Pygmy-Owl Glaucidium bolivianum Scientific name definitions

The Yungas Pygmy-Owl is very similar to the Andean Pygmy-Owl (Glaucidium jardinii), indeed until very recently it was not recognized as a distinct species. The primary difference between the two species is in the pace of the song: typically three-four notes per second in Andean, but a more languid one-two notes per second in Yungas. As is the case with Andean, the Yungas Pygmy-Owl occurs in several color morphs. A brown and a red or rufous color morph are common and widespread, but a gray morph apparently is restricted to southern Bolivia and northern Argentina. The Yungas Pygmy-Owl is uncommon to fairly common in humid montane forest of the Andes along the east slope of the Andes, where it occurs at higher elevations than any other species of Glaucidium. As is typical of Glaucidium, this species is partially diurnal, although it may be more nocturnal in the southern part of its range.  The Yungas Pygmy-Owl hunts for invertebrates and small vertebrates from perches in the canopy, and frequently is mobbed by the small passerines that it hunts.

c. 16 cm; male 55–58 g, female 66·5 g (mean of 13 birds) (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ). Small pygmy-owl with spots on crown, prominent "false eyes" on nape, pale dots on back and upper wings  and pale undersides with brownish mottling on sides of upper breast and brownish streaks on flanks and belly. Similar to G. jardinii but with more densely spotted crown, usually more barring on sides of chest and shorter streaks on flanks, shorter tail. Irides golden-yellow; cere and bill greenish-yellow; toes dirty yellow (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ). Occurs in brown, grey and rufous morphs. Juvenile with unmarked crown, flank streaks more diffuse.

E slope of Andes in Peru, WC Bolivia and NW Argentina.

Montane forest and cloudforest; partial to Alnus groves with dense undergrowth and areas with heavy presence of thick moss and epiphytes; also Podocarpus forest. Usually high in the canopy or at middle levels. Generally at elevations from 1400–3000 m, locally down to 900 m; occurs in Polylepis forest at 3700–3900 m in Bolivia (2 Herzog, S. K., R. Soria, and E. Matthysen (2003). Seasonal variation in avian community composition in a high-Andean Polylepis (Rosaceae) forest fragment. Wilson Bulletin 115(4):438–445. Close ).

Probably mostly resident (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ), although might perform some elevational movements.

Poorly studied. Takes insects and other arthropods, small birds, possibly also reptiles. Mostly nocturnal and crepuscular; appears to be less diurnal than other Glaucidium in range (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ). Forages mostly in canopy and in dense foliage below canopy (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ).

2 or 3 whistled notes followed by trill  , then rather slow series of equally spaced hollow notes  ; often omits first part, utters just the slow series for long periods.

Little information. Nesting territories in NW Argentina 0·5–1 km² on treed slopes (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ). Probably nests mostly in old woodpecker holes.

Not globally threatened (Least Concern). CITES II. Appears to have declined since first described (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ). Forest destruction and degradation probably main threat, although inaccessibility of parts of range should afford some protection. No estimate of global population size. Occurs in several protected areas through range, e.g. Cotapata National Park, La Paz (Bolivia), and Calilegua National Park, Jujuy (Argentina); in latter, considered fairly common.