Shiny Cowbird
Encyclopedia : S : SH : SHI : Shiny Cowbird
The Shiny Cowbird, Molothrus bonariensis, is a passerine bird in the New World family Icteridae. It breeds in most of South America apart from dense jungle and mountains, and on Trinidad and Tobago. It has relatively recently colonised Chile and many Caribbean islands, and has reached the USA, where it is probably breeding in southern Florida. Northern and southernmost populations are partially migratory.
It is a bird associated with open woodland and cultivation. The male’s song is a purr and whistle, purr purr purrte-tseeeee. The male’s call is a sharp whistled tsee-tsee, but the female makes a harsh rattle.
Like other cowbirds, it is brood parasite, laying its eggs in the nests of many other bird species. The eggs are of two types, either whitish and unspotted, or pale blue or green with dark spots and blotches. The host’s eggs are sometimes removed, and if food is short their chicks may starve, but larger host species are less affected. The incubation period of 11-12 days is shorter than that of most hosts.
The male Shiny Cowbird is 20.3 cm long, weighs 45 g and is all black with an iridescent purple-blue gloss. The smaller female is 19 cm long and weighs 31 g. Her plumage is dark brown, paler on the underparts. She can be distinguished rom female Brown-headed Cowbird by her longer, finer bill, pale superciilium and stronger face pattern. There is an all-black plumage variation, and the northern subspecies M. b. cabanisii of Panama and northern Colombia is paler than the nominate M. b. bonariensis. Juveniles are like the female but more streaked below.
This abundant and gregarious bird feeds mainly on insects and some seeds, including rice, and forages on the ground or perches on cattle.
References
- BirdLife International (2004). [Molothrus bonariensis]. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 05 May 2006. Database entry includes justification for why this species is of least concern
- New World Blackbirds by Jaramillo and Burke, ISBN 0-7136-4333-1
- Birds of Venezuela by Hilty, ISBN 0-7136-6418-5
- Birds of Trinidad and Tobago by ffrench, ISBN 0-7136-6759-1
External links
- [Shiny Cowbird videos] on the Internet Bird Collection
From Wikipedia, the Free Encyclopedia. Original article here. Support Wikipedia by contributing or donating.
All text is available under the terms of the GNU Free Documentation License See Wikipedia Copyrights for details.