Spring morning, Discovery Park, Seattle

The Brothers, over in the Olympic Range, sport a fresh layer of snow...



big-leaf maple blooms...



fiddleheads unroll... (At this stage, I can't tell what kind of fern it is.)



..and biologists roam the woods wielding strange equipment.

This is Kayla Helem, an undergraduate at the University of Washington. She is working with Caglar Ackay, a University of Washington PhD candidate, on research into the private lives of song sparrows. It's a continuation of decades of work on Discovery Park's song sparrows by Mike Beecher's lab.
Song sparrows are monogamous, but genetic studies show that they sometimes mate with sparrows other than the ones they raise chicks with. (What biologists call "extra-pair mating.") So researchers have fitted some song sparrows with radio transmitting backpacks. Now they are tracking the birds' movements.
"We're trying to figure out who's leaving the territory, the male or the female," Helem says.