Sunday, January 8, 2012

Plumbeous Vireo

Last week, Roselvy and I moved into our new house in Santa Ana, in the department of Francisco Morazan, Honduras, where we will be working with birds for an entire year. We already love it here, with lots of cool birds in the surrounding pine-oak forests.

One notable member of the bird community here is a Central American subspecies of Plumbeous Vireo.

Plumbeous Vireo became its own species in 1997, when the AOU split the Solitary Vireo into three species: Cassin's, Plumbeous and Blue-headed Vireo. All three are field-identifiable, with the most western Cassin's Vireo of California, Oregon, Washington and southern British Columbia more or less intermediate in appearance between the drab gray Plumbeous Vireo of the Intermountain West and the more colorful Blue-headed Vireo of the northeastern and boreal forest.

The Central American subspecies of the Plumbeous Vireo found in El Salvador and Honduras is actually more similar to Cassin's Vireo than it is to northern Plumbeous Vireo populations. Currently, the two subspecies recognized in Central America are notius (Belize) and montanus (El Salvador and Honduras), although these subspecies sometimes have been considered synonymous (Curson & Goguen 1998). Monroe (1968) considered the Honduran subspecies to be notius rather than montanus.

In this subspecies, the sides of the breast and belly are greenish (not gray), the secondaries have greenish edges (not gray), and there is a subtle contrast between the blueish gray head and the greenish gray back, unlike the all-gray head and back of the northern Plumbeous Vireo.

The vocalizations are different too. Here's some footage of a bird calling in response to my Ferruginous Pygmy-Owl imitation.

I also recorded some song. The same individual first sang a more or less continuous song, followed by a different song consisting of shorter, more hesitant phrases.

Cited literature
Curson, David R. and Christopher B. Goguen. 1998. Plumbeous Vireo (Vireo plumbeus), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online:
Monroe, Jr., B. L. 1968. A distributional survey of the birds of Honduras. Ornithol. Monogr. 7.

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