The yellow-rumped warblers arrived a mid-May morning. They were ravenous for the insect hatch that hovered above a puddle by the Airport Dike Trail. A dozen male warblers flitted out from the leafless willows.
Flap, hover, snatch and loop back to the willows — a sally out forage technique.
The thin bill of these birds alludes to an insect diet. But a second glance reveals it’s not so thin; these warblers’ systems can also handle seeds, fruits and berries. This food range enables the yellow-rumped warbler to remain north longer than other warblers and they needn’t migrate as far south. That gives these warblers a jump on a spring return to their breeding grounds.
The males are the first to return. They arrive to claim an outdoor restaurant of sorts, a productive food territory. Having already molted, these are devilishly handsome birds with streaks of black on slate blue backs, bold white wing patches, brilliant yellow patches on the crown, throat, flank and rump, with a dark face and white eye crescents. The females are a muted version of the male’s coloration.
There are two subspecies of yellow-rumped warblers. Guide books tell readers of the east coast “Myrtle” with a white throat, white eye stripe and two white wing bars. There is also a west coast “Audubon” with a yellow throat and white wing patches. In Alaska, you can see both. Southeast Alaskans spot the “Audubon” version more often. Bob Armstrong’s photo shows that they may interbreed in our area.
I’m keeping a lookout around the edges of patchy deciduous/coniferous woods for a small, squatty nest, about three inches by two inches in size. Perhaps you’ll spot it before me, mid-way up a tree, out on a horizontal limb or tucked up close to the tree trunk, as in the photo. We’re getting warm if our eye is snagged by splotches of yellow, black and white … hopping, stooping, clinging, fly-catching or calling while zipping between trees.
• Patricia Wherry is the director of education for the Juneau Audubon Society. Contact her at education@juneau_audubon_society.org.