Black-cheeked Warbler

Taxobox
name = Black-cheeked Warbler
status = LC | status_system = IUCN3.1
regnum = Animalia
phylum = Chordata
classis = Aves
ordo = Passeriformes
familia = Parulidae
genus = "Basileuterus"
species = "B. melanogenys"
binomial = "Basileuterus melanogenys"
binomial_authority = Baird, 1865The Black-cheeked Warbler ("Basileuterus melanogenys") is a New World warbler which is a resident breeding bird endemic to the mountains of central and southern Costa Rica and western Panama.

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 1600m. 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.

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.

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.

The Black-cheeked Warbler primarily feeds on insects, spiders and other small invertebrates, taken low in the undergrowth.

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".

References

* Database entry includes justification for why this species is of least concern
* Curson, Quinn and Beadle,"New World Warblers" ISBN 978-0-7136-3932-2
* Stiles and Skutch, "A guide to the birds of Costa Rica" ISBN 978-0-8014-9600-4