This week’s Bird of the Week, compliments of the Weminuche Audubon Society and Audubon Rockies, is the orange-crowned warbler.
For a warbler, the orange-crowned is remarkably plain. Its yellow-green coloration serves to hide it well deep within the oak and shrubs where it spends its time. Distinguishing marks of this small bird include a thin, pointy bill, faint eye line and broken eye ring, and faint breast streaks. Its orangish head patch is usually concealed.
Leaving early from its winter grounds in southern California, Mexico and the Caribbean, the orange-crowned arrives here in late April. It breeds in a wide range of habitats across the western states and into Canada and Alaska. This warbler nests on or near the ground on shady hillsides, and on the steep terrain of road cuts and canyons. It will tolerate other warbler and sparrow species nesting in its territory, but chases off competing orange-crowneds. Here, it is often found in the company of Virginia’s warblers.
The male sings a unique, rapidly trilled song, described by a local birder as sounding like a telephone ring. Chipping sparrows and juncos sing a similar trilled song. Breeding males in adjacent territories will learn and mimic each other’s song, forming song neighborhoods.
These birds mainly eat invertebrates which they uncover by poking through leaf litter, probing bark, and picking over leaves and buds. They will also dine on berries, fruits, seeds and plant galls, and visit the sapwells created by sapsuckers. Food supply, not day length, triggers fall migration, and orange-crowned warblers may stay longer and farther north than other warblers before heading south for the winter.
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