13 March 2010

Even More from Rio Ayampe: Esmeraldas vs. Little Woodstar...(Ecuador): 4 - 6 Feb 2010

One of the standout birds on this years southern Ecuador tour was the Esmeraldas Woodstar. This tiny hummingbird is listed as endangered, with a population estimate possibly as low as a mere 250 birds. This little hummer is confined to southern Ecuador, and although is reasonably reliable in the early part of the year in this Ayampe area, it is seldom numerous, and after this period promptly vanishes, to where no one really knows. So in short it is a rare endemic that is shrouded in mystery, all of which make it an interesting subject.

Although I was fairly confident we would find one, I was not expecting to run into at least nine different individuals during our time there, of both males and females (an unusually high total.) .The female remains poorly illustrated in the guides, and perhaps as a result are sometimes misleadingly identified as Little Woodstars (that are also present in this area). For this reason I have included a photo of a female and a summary of what I personally think is best to look for in order to separate female Esmeraldas Woodstars from Little Woodstars:

Female Esmeraldas are not as white underneath as all the book plates indicate. Indeed they can have a strong rufous wash, much as Little Woodstars do too. Two main areas should be looked at, the FACE (especially the throat and supercilium), and the TAIL. Most illustrations indicate Esmeraldas have all white UNDERPARTS, which I think is often not true (bottom three photos). The other thing to look for on an Esmeraldas is that the broad supercilium and throat appear whitish, compared with deep rufous on a Little. Furthermore, the TAIL should be looked at. On a Little the TAIL will be generally all bright rufous with a broad, dark horizontal band across the center. On an Esmeraldas female the TAIL will be dark with a pale tip (that may appear rufous)...

Anyway these are my preliminary thoughts on the subject. During this time I observed a number of female and male Esmeraldas Woodstars feeding side by side. Above is a photo of a female Esmeraldas (top),
another photo of a male for the hell of it (second), along with picture of the flowers that so many of them were frequenting during this rich time for them at Ayampe (third).

1 comment:

Bert Harris said...

Dear Sam,

Some birders from Peru have been looking at your post on Esmeraldas Woodstar identification and coming to incorrect conclusions. The field guide drawings of "female" Esmeraldas Woodstars you have posted are based on specimens of juvenile males. Could you please email me? Then I will send you our research on this. Your site is very influential and it would be great if we could amend the information there. Thanks! Bert