May 2020 saw an explosion of Yellow Rumped Warblers sightings in Southern Alberta, as COVID-19 kept people at home in Calgary. Looking out their windows in isolation, folks finally noticed birds migrating through, and took notice of our most common wood warbler – who, given the fabulous grey and yellow colouring, is hard not to do.
A or B?
Yellow Rumps come in two subspecies. They used to be distinct species, but they have now been merged. The Audubon features a yellow throat, the Myrtle a white/grey throat. They also interbreed, making ID even more complex. However, the yellow rump is always there. Photos of both subspecies are included on this page. Can you spot the differences?
Habitat & diet
While Yellow Rumps do hang out in forests (and not normally near the tops of the trees, making them nice to watch), they like wet areas, streams and lakes. The main part of their diet is flying insects, and you will often see them hanging out by the banks of the Bow or Kananaskis Rivers, flitting out, grabbing a bug, and flitting back. They also eat ants and other things that creep and crawl.
The colours of the males seem to pop at spring mating season. They mate very soon after returning from their southwestern US and Mexico wintering grounds, and nest fairly low, typically within ~10 m of the ground. By late June or early July, the young are a 
relatively common sight, especially in the higher alpine, though only the yellow rump patch has developed by then, and they remain mostly “meh-gray”.
While they transit Calgary, they normally don’t live there. They’re a mountain or boreal forest bird, meaning if you enjoy them when they passed through Calgary, you need to come out to K-Country see them during most of the season.
Meet some of the other critters of K-Country here!
