Spring bird migration is underway, and Wilson’s warblers have begun to arrive in Capitol Hill. Some of these birds are just stopping over to browse our shrubbery for bugs before flying farther north to Canada or Alaska. Many, however, will stay all summer, breeding here and eating our bugs for the duration.

The Wilson’s warbler is easy to identify: a tiny bird with a black cap, bright yellow breast, and dirty olive-colored wings. It spends its winters in warmer climes—but don’t get too jealous. Every year, it makes the trip to Mexico or Central America and back on its own power.

We’ve seen birds that fly up to 60 miles per hour; now we’re seeing birds that fly up to 5,000 miles.

Wilson’s Warbler, originally uploaded by ap..

Before Wilson’s warblers migrate, they gain as much weight as they can—which isn’t much, as the heaviest top out around 8 grams. They’re nocturnal migrants, so they set out at dusk and fly until dawn. Because they’re so small, they frequently get blown off-course by storms.

After a night’s flight, Wilson’s warblers stop at the first safe spot they can find. There they rest and feed to recuperate the weight they lost during their nighttime journey. Rest stops vary in length depending on stressors and food availability, but they can last a couple of weeks.

You might see a Wilson’s warbler foraging for food anywhere in the neighborhood. They nest in shrubs near freshwater lakes and streams, so if you’d like to look for these birds near Capitol Hill, head down to Lake Washington and look along the shoreline.

Interested in learning more?

• For fun facts and general information about the Wilson’s warbler, see their page at the Cornell Lab of Ornithology.
• If you plan to go out looking for a Wilson’s warbler, consider studying its call and song at the Macaulay Library of Natural Sounds.
• If you’re a bird nerd like me, you might enjoy testing your skills on these warbler quizzes at the Sibley Guides website. 

Previous Aviary Posts

• An update on the owls of Interlaken
• The adaptive reuse of Capitol Hill chickadees
• That’s not rain, that’s the hum of Hill hummingbirds looking to get laid