This week’s Bird of the Week, compliments of the Weminuche Audubon Society and Audubon Rockies, is the Grace’s warbler.
June is the month of an affliction known as warbler neck. It is the result of spending too much time with your head tilted back while focusing binoculars on the treetops in search of the small, often colorful migratory birds known as warblers. In the company of people who love spying on birds, the condition can be contagious.
Warblers belong to a large family of birds, the Parulidae, with more than 115 different species spread throughout North, South and Central America, and the Caribbean. They are vocal, active insectivorous birds that are a challenge to track. Most have thin, tweezer-like beaks designed for capturing insects.
Fifty-six warbler species spend time in the United States and Canada. Spring migration coincides with leaf out, when tiny caterpillars are hatching to feed on leaves. Warblers eat a huge number of these insects before they can do serious damage to trees.
The Grace’s warbler is a specialist of mature pine forests in parts of the southwest United States and areas to the south. Here it stays in the ponderosa treetops, where it gleans small branches, twigs and clumps of needles to catch insects and spiders. Sometimes it sallies out to snatch an insect flying by. It usually stays well away from the tree trunk, even building its tiny woven nest inside a pine needle cluster near the outer edge of a tree.
Measuring less than 5 inches, the Grace’s is one of the smallest warblers. Its upperparts are gray, it has two white wingbars, and the bright yellow of its throat extends above the eyes. Tracking its song in the treetops is the best way to find its location.
Because its territories are large, nests are well hidden and individuals are a challenge to follow, the Grace’s warbler is one of the least-studied birds in the United States. It is known to be a victim of brown-headed cowbird nest parasitism.
Likely due to a loss of mature pine forests in the United States and Mexico, Grace’s warblers are on the Partners In Flight watch list for species in serious decline.
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