Yellow-rumped warbler male singing. Credit: Rhododendrites/Wikimedia Commons, CC BY-SA
Squinting through my binoculars, I scanned the dense branches of a black spruce, trying my best to catch a glimpse of the thin legs of a small black, white and yellow songbird. I was on the hunt for a yellow-rumped warbler—a bird affectionately called "butter-butt" by birdwatchers after the distinctive buttery yellow patch of feathers above its tail.
Once I spotted a flash of red on one of the bird's legs, I knew that this individual was special—in fact, it was one that I already knew well. That's because I had placed identifying bands on it the previous year as part of my Ph.D. research, and it was carrying a very important piece of new technology.
I played the high-pitched "warble" of its song through a speaker placed below a mist net of fine, nearly invisible mesh. Thinking another male had intruded on his territory, the bird quickly descended. My tactic worked—he got caught in the net. As I gently removed him, I breathed a sigh of relief as I saw the Tic Tac-size device sitting on his back.
Over the past year, this warbler carried a multisensor geolocator backpack throughout his migratory journey, recording the long trek from his breeding grounds in Anchorage, Alaska, to an as-yet-unknown winter refuge and back again. Working with my Ph.D. adviser, evolutionary biologist David Toews, I deployed dozens of these cutting-edge tags to illuminate the migratory journeys of these high-latitude breeding warblers at a scale not previously possible for small birds.
