Welcome back! This week I wanted to share some photos of one of my favourite summer birds, the yellow warbler. It doesn’t feel like summer until I hear the males singing out their sweet whistling song. Honestly sometimes summer is most often still a few weeks off as Yellow warblers arrive in Yellowknife before the leaves emerge on the trees!
Males are bright yellow with reddish streaking on their breasts while females are pale yellow with a grey-green back. Yellow warblers don’t have an eye line or an eye ring and lack bars on their wings. They are one of the easiest of the warblers to identify due to their lack of field marks! Juveniles birds are grey-green with yellow tones emerging as they grow. Juveniles can be much more difficult to identify in the field as they look very similar to Tennessee and Orange-crowned warblers.
I’ve been fortunate to enjoy watching multiple pairs of yellow warblers nest and raise their young in our neighbourhood. Their nests in our area are made with grasses, twigs, and willow cotton. I have seen nests in birch and aspen trees though I am sure they nest in other trees as well provided there is a good anchor point. In places where cowbirds and yellow warbler territory overlap, Yellow warblers have a unique strategy to avoid parasitic eggs. If a cowbird lays its eggs in a Yellow Warbler’s nest, the warbler often begins building a new nest directly on top of the old one, abandoning both its own eggs and the cowbird’s. Sometimes there can be up to 6 nests one on top of the other!
As we don’t have cowbirds in Yellowknife, I expect these youngsters were raised in “regular” sized nests. I had some difficulty identifying the fledglings until the parents came by to feed them. Many warblers have dull coloured and streaky feathers to help them remain camouflaged from predators. Once they are out and about for a couple of weeks, it seems the colours of their feathers start to appear.
And finally, the interesting fact about bird ages: The oldest-known Yellow Warbler was a female and was at least 11 years old when she was re-captured and re-released during banding operations in New York.