This week’s Bird of the Week, compliments of the Weminuche Audubon Society and Audubon Rockies, is the Townsend’s warbler.
In late summer, many of the colorful birds that have spent the summer here are migrating south for the winter. They arrived in late spring to claim a nest site and raise young when the insects they rely on for food are abundant, but are now moving on.
For a few weeks in late summer and early fall, the Townsend’s warbler provides the splash of yellow missing in the trees with the departure of our summer wood-warblers. The small adult male has a yellow face with a black cheek patch, a black cap and throat, and a yellow breast streaked with black. Its back is olive-green and his gray wings have white wingbars. In females and immatures, colors are paler and the throat is yellow.
In the fall, the Townsend’s migratory journey is spread out over a long period and in a wide pathway over the western third of the United States. Some follow the West Coast to winter in California and the Baja Peninsula, while others travel inland to the highlands of central Mexico and Central America.
These warblers breed in old-growth fir forests from southern Alaska and northwestern Canada to the Pacific Northwest in the United States. In summer they both nest and forage high in the canopy, making them a challenge to see and study. After their young have fledged, they will hunt for food lower and feed in shrubs, bushes and on the ground.
Townsend’s warblers feed on a variety of insects and larvae by gleaning conifer needles and buds, and on occasion they dart out for flying insects. On their winter grounds, they switch to a nectar-rich diet, favoring honeydew, a sticky, sugary liquid produced by some insects that feed on plant sap. The birds will guard territories that include trees infested with honeydew-producing insects. During winter, they will come to feeders to eat mealworms, peanut butter and suet.
To discover how many nocturnal migrant birds are crossing Archuleta County skies each night, investigate the Birdcast website.
For information on events, visit www.weminucheaudubon.org and www.facebook.com/weminucheaudubon/.