Yellow-breasted Warbler Phylloscopus montis Scientific name definitions

9·5–10 cm; c. 5 g. Small and highly active warbler with yellow underparts. Nominate race has crown, supercilium and ear-coverts rufous-chestnut, black lateral crownstripe extending to nape; upperparts olive-green, becoming yellow on rump and uppertail-coverts; two yellow bars formed by tips of median and greater wing-coverts; tail feathers dark brown, fringed olive-green; throat and underparts deep yellow, some rufous streaking on breast; underwing-coverts yellow; iris dark brown, bold whitish eyering; upper mandible dark brown, lower mandible yellowish-flesh; legs fleshy-brown, soles paler. Differs from P. castaniceps in having entire underparts yellow, chestnut hood extending down over ear-coverts, no grey in plumage, no white in tail. Sexes alike. Juvenile is duller overall than adult, has less extensive rufous on head, not extending to breast, less well-defined lateral crownstripes, paler yellow underparts. Races vary rather little: davisoni resembles nominate, but has more extensive rufous hood breaking up into streaking at side of breast; barisanus and xanthopygius similar to nominate, with little rufous on breast side; floris lacks yellow on rump, has lateral crownstripe weakly defined; paulinae differs from last in slightly larger size (on average), even weaker crownstripe, is paler olive above, with distinctly yellowish rump.

Editor's Note: This article requires further editing work to merge existing content into the appropriate Subspecies sections. Please bear with us while this update takes place.

Previously placed in Seicercus; see Phylloscopidae. Sometimes treated as conspecific with P. sumatrensis and P. grammiceps (1 Eaton, J. A., B. van Balen, N. W. Brickle, and F. E. Rheindt (2016). Birds of the Indonesian Archipelago: Greater Sundas and Wallacea. Lynx Edicions, Barcelona, Spain. Close ). With merging of Seicercus and Phylloscopus, subspecies name inornatus becomes preoccupied; recently replaced by new name barisanus (2 del Hoyo, J., and N. J. Collar (2016). HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions, Barcelona, Spain. Close ). Six subspecies recognized.

Editor's Note: Additional distribution information for this taxon can be found in the 'Subspecies' article above. In the future we will develop a range-wide distribution article.

Insects and other small invertebrates. Forages actively in understorey or mid-canopy at forest edge; occasionally descends to low undergrowth, but typically works just inside foliage of middle canopy. Gleans food items; readily hovers while picking insects from underside of leaves, also indulges in quick flycatching sallies. Associates with roving mixed-species flocks outside breeding season.

Song very high-pitched, described as a high-frequency, slurred series of notes, “zizizizizizi-azuuuu”, rising and then fading away, repeated 5–6 times per minute, interspersed with sharp “chit chit” notes; has same ethereal quality as song of P. castaniceps.

Little information. Breeds Jan–Jul in Peninsular Malaysia; males in breeding condition in Jun and Aug on Flores. Reported as building a domed nest in hole on bank. Clutch of 2 eggs reported, but no further information.