Tiny backpacks reveal the secret, sometimes circuitous migrations of small songbirds

A tracker must be light enough to not weigh down a bird that weighs only as much as a spoonful of sugar. Thor Veen

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 bird-watchers after the distinctive buttery yellow patch of feathers above its tail.

Stephanie Szarmach holds a yellow-rumped warbler that was banded as part of a study. Johanna Beam