Western Bonelli's Warbler

Western Bonelli's warbler is a small passerine bird, found in forest and woodland. Four to six eggs are laid in a nest on the ground. The eggs are white with reddish-brown markings and are laid in clutches of 3-5 eggs. The incubation period is around 14 days long, and the chicks fledge after 10-14 days. Cuckoo nest predation and brood parasitism are major hazards to the breeding success of western Bonelli's warblers. Like most warblers, western Bonelli's warbler is insectivorous. The adult has a plain grey-green back, green-toned rump and wings and whitish underparts. The bill is small and pointed and the legs brown. The sexes are identical, as with most warblers. The western Bonelli's warbler has a browner tinge to the upperparts than the eastern Bonelli's warbler; the latter sometimes has a greenish tinge instead. The song is a fast monotone trill, only slightly different from eastern Bonelli's, and also with some similarity to the wood warbler. The call of the western Bonelli's warbler is a disyllabic hu-it, differing from that of the eastern Bonelli's warbler which is a hard chup, reminiscent of a crossbill or a house sparrow.