Tuesday, September 7, 2010

Molting starthroats

Plain-capped Starthroat preening

I've been frequenting the San Salvador botanical garden lately, which is only a 15 minute bus ride from my apartment, and offers opportunity for study of hummingbirds. Sadly, it is not the oasis of tranquility it could be, and many botanical gardens across the world often are. The garden is located inside an old volcano crater, right next to a noisy factory, and practically every weekday and Saturday gets inundated with school kids. Despite all that, the garden boasts a number of flowering trees and shrubs, and these of course attract hummingbirds.

The Plain-capped Starthroats I reported on a couple of weeks ago, have become regulars for me. These birds very likely are residents of the garden, and possibly breed there.

I've noticed that at least one of these birds is in flight feather molt, i.e. undergoing a post-breeding prebasic molt.

The photo at the top of a bird preening is of poor quality, but shows a spread wing with all six secondaries. Clearly visible are new (darker) S1 and S2, an ingrowing S3, and old (paler) S4-6. Click on the photos for bigger views.

Plain-capped Starthroat

The bird in this photo, taken in the botanical garden also but on a different day, could be the same individual, or could be its mate. Note that this bird is molting its central rectrices. This photo too is heavily cropped, and of poor quality. Still, we can see molt centers in the wings also: both in the secondaries and primaries.

Last week I noted the arrival of Green-breasted Mangos in the garden. First there was one adult male. Last Saturday, that male was gone but a female was there. And Sunday, I found no less than five males and a female, all in the same tree! I wonder if these birds are passing through, or will spend the winter in the botanical garden.

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