Tuesday, May 11, 2010

Snail Kites over Cerrón Grande

This bird, carrying a snail in its bill, is of course a Snail Kite. I photographed it today during a 2-hour boat ride on the Embalse Cerrón Grande (sometimes called Lago Suchitlán), some 50 km north of San Salvador. Suchitoto is a pretty, colonial town near this reservoir. The town has been there for centuries; the reservoir, however, has not. It was created in the winter of 1976, when a hydroelectric dam was built.

Even more recent than the lake here is the bird: according to wikipedia, Snail Kite was first recorded in El Salvador in 1996 - 20 years later. Indeed, Howell & Webb's Guide to Birds of Mexico and Northern Central America does not show this bird for El Salvador, nor does the BNA account for the species. Both publications date from 1995.

I don't know if breeding has been recorded in El Salvador for Snail Kite. Today, I only saw adult males, no females or immatures. I wondered if maybe the females were incubating, but as I later learned, in this species incubation is shared by both sexes, with the females doing most of the incubation at night (Sykes et al. 1995). Given that scenario, I would have been at least if not more likely to see feeding females in the middle of the day...

It seems likely to me that Snail Kite breeds here, though, given the local abundance of apple snails...

Postscript 8 June 2010:
In Aratinga 4 (2010), the organ of the Salvadoran branch of Partners in Flight / Compañeros en Vuelo, which just came out today, Salvadoran biologist Ricardo Ibarra Portillo describes two Snail Kite nests found in July of 2008 at this very site! He also mentions that prior to these records, the species had already been found to nest elsewhere in El Salvador, in Lago de Guija to be exact. A paper describing first breeding of Snail Kite in El Salvador is in preparation.

Cited literature:
Howell, S.N.G. and S. Webb. 1995. A Guide to the Birds of Mexico and Northern Central America. Oxford University Press, New York
Sykes, Jr., P. W., J. A. Rodgers, Jr. and R. E. Bennetts. 1995. Snail Kite (Rostrhamus sociabilis), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/171

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