Sunday, August 22, 2010


Most of the flowerpiercers in the genus Diglossa, which currently includes 14 species, are found in the highlands of South America. Two species occur in Central America, including the Cinnamon-bellied Flowerpiercer (Diglossa baritula) of which the male is pictured above.

As the common name suggests, these birds are nectarivorous. Because they feed on the same substrate, they're often found with hummingbirds, but instead of hovering in front of a flower and inserting a long bill, these birds have developed a different strategy. They perch at the base of the flower and with their uniquely shaped bill pierce a little hole in it, allowing them access to the flower's nectar that way.

Here's the duller female of the same species. (Clicking on the photo for a bigger view will reveal that this particular individual has a sizable tick feeding on the lower edge of her eye.) I photographed these birds last week in Monte Uyuca, Honduras, where I assisted Roselvy, Carlos and Vicky in SalvaNATURA's bird monitoring project. This is a monthly bird banding effort that started in January of this year, and which has been covered before in this blog. We banded about 75 birds there this time - but no flowerpiercers. A few months ago, we caught a ton of hummingbirds and quite a few flowerpiercers. This time around, only three hummers (two Green-breasted Mountain-gems and one Magnificent Hummingbird). Nearly all the hummingbirds and flowerpiercers, it seems, had moved 500-800 m downslope from the net lanes, for that is where I found these birds to be abundant this week. I even saw a male Cinnamon-bellied Flowerpiercer with one of our bands, about 600 m from the banding site.

It's possible that I banded this bird myself, although it is more likely to have been banded by either Roselvy or Carlos. Roselvy has been on all eight banding trips to the site, Carlos on seven I believe, while I have accompanied them on five. Altitudinal migration is well-known among tropical nectarivorous birds, as they opportunistically move from one area where flowers are blooming this month, to another area next month.

Once thought to be related to the sparrows and buntings of the New World, recent studies have shown flowerpiercers to be more closely related to the tanagers. The Cinnamon-bellied Flowerpiercer is found in Mexico, Guatemala, El Salvador and Honduras.

The other Central American flowerpiercer is Slaty Flowerpiercer (Diglossa plumbea), found in Costa Rica and western Panama. These birds are common in the Chiriquí highlands of western Panama, where Roselvy and I stayed for a week recently.

This is the male of the species; the female is duller brown, like the female Cinnamon-bellied.

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