Appearance
The black-cheeked warbler is 13-13.5 cm long and weighs 13 g. It has a rufous crown, long white supercilia and black cheeks. The upperparts are dull olive, the breast is olive-grey, and the belly is yellow-white. The sexes are similar, but the young bird is browner on the upperparts, has a dull supercilium, a greyer breast, and shows two cinnamon wingbars.
Naming
Despite this species’ restricted range, it has three subspecies.⤷ ''B. m. melanogenys'', the nominate race described above, breeds in central and southern Costa Rica.
⤷ ''B. m. eximius'' is highly localised in a small area of western Panama, and is slightly whiter on the belly than ''melanogenys''.
⤷ ''B. m. bensoni'' is highly localised in a small area of west-central Panama, and is whiter below than ''eximius'', and a purer grey above.
Behavior
The call note of the black-cheeked warbler is a hard ''tsit'', and the male’s song is a lisping spluttered ''tsi tsi wee tsi tsi wu tsi wee''.Habitat
It is normally found in oak forests with a dense bamboo understory from 2500 m altitude to the timberline, but occasionally occurs as low as 1600 m. The breeding pair builds a bulky domed nest with a side entrance on a sloping bank or in a gully, and the female lays two white eggs.Food
The black-cheeked warbler primarily feeds on insects, spiders and other small invertebrates, taken low in the undergrowth.References:
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