Tuesday, December 30, 2008

Bingo!

This awesome bird is a Blue-throated Motmot. It occurs here in montane forests, but is nowhere common in its fairly small Central American range. Ever since I’d seen its name on the checklist for Huitepec, it had been pretty high on my wish list. Motmots are fantastic, charismatic birds, and I was thrilled when I spotted this bird sitting at mid-level in the understory of mature oak forest in Huitepec.

After Pink-headed Warbler, Hooded Grosbeak, Garnet-throated Hummingbird, Green-throated Mountain Gem and Black-capped Swallow, this Blue-throated Motmot was the sixth ‘lifer’ for me here in Chiapas.

This was our fifth and final day at the Huitepec site, and it was now or never for Golden-cheeked Warbler.

We found one! Again it was a male, and although I saw this bird for only half a second, I saw it well enough to call it. Unfortunately, I only saw the head and upper parts of the bird, never the feet, so I can’t say if it was banded or not.

It was part of the biggest flock we’ve encountered at this site, in which I was able to identify 39 individuals of 17 different species. Interestingly, the bird we found last week in Moxviquil was also part of the biggest flock we encountered at that site.

Today’s flock was heavy on Crescent-chested Warblers, of which I counted at least 9 individuals. When there’s 20-30 birds flitting through the treetops, it’s hard to identify all of them at the same time, and to know which ones you already identified earlier. But, as I said to my field assistant Hector, seeing a mixed warbler flock move through the trees overhead really is birding heaven. For me, it doesn’t get any better than this. Much as I love raptors, there is nothing like the sight of these small creatures darting through the leaves in search of insects. Sure, it’s hard work, keeping up with the flow of the group and identifying birds that are often half-hid among leaves or behind branches, but incredibly satisfying too. I love doing this work.

The flock had at least 6 Townsend’s Warblers. According to Dunn & Garrett’s Warbler Guide, “in Chiapas, Golden-cheeks are estimated to be only about 1 percent as numerous as Townsend’s Warblers” (1). This sentence intrigued me mightily, and I did some research online to find out where Dunn & Garrett get this number from. Turns out this figure is presented in Vidal, Macías-Caballero & Duncan (1994), an article published in The Condor, titled "The occurrence and ecology of the Golden-cheeked Warbler in the highlands of Northern Chiapas, Mexico" (2). For anyone interested in the article, it can be downloaded freely here: http://elibrary.unm.edu/sora/Condor/files/issues/v096n03/p0684-p0691.pdf

It’s an interesting article. Their methodology then was quite different from ours now, so there is really no point in comparing their results to ours. Of course we’re only two weeks into the field work here. I’ve been thinking a lot these past days about why we’re not seeing more goldencheeks, and to me it seems a matter of habitat. I think this species is more abundant in pine-oak forests, and less abundant in young (Moxviquil) or older (Huitepec) oak forests. Upcoming sites I believe have more pines, so I expect to be seeing more goldencheeks in the coming three weeks.

Another incredibly charismatic bird in the mixed species flocks is the well-known Black-and-white Warbler. This is an immature male, acrobatically hanging upside down, reaching for insects and small invertebrates that other warblers can't reach.


(1)
Jon L. Dunn & Kimball Garrett (1997) A field guide to warblers of North America; Peterson Field Guide Series, 49. Quoted sentence is found on page 294.

(2)
Vidal, Macías-Caballero & Duncan (1994) The occurrence and ecology of the Golden-cheeked Warbler in the highlands of Northern Chiapas, Mexico. Condor 96: 684-691.

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