11 October 2022
As the September wave of migrating warblers disappears to our south the next wave of birds has arrived from the north, among them ruby-crowned kinglets (Corthylio calendula). These tiny dynamos resemble the plainest warblers and vireos but are so unique that it’s worth taking a closer look at them.
For starters, though ruby-crowns are called kinglets they are no longer in the same genus as golden-crowned kinglets (Regulus satrapa). In 2021, thanks to DNA and some very unique traits, the AOS placed them in a genus all their own: Corthylio.
Smaller than any warbler, ruby-crowned kinglets are olive-green with somewhat whitish bellies. Their most reliable trait is their constant wing-flicking, punctuated by rapid darting to and fro. They also have:
- Two white wingbars,
- Big white eyerings broken at the corners,
- A tiny beak
- No neck
- A proportionally larger head compared to the look of a warbler
- Thin black legs with golden feet
- A dry call note and a rousing song
- Males have red or orange feathers hidden atop their heads which they raise when agitated.
On any particular bird you may never see a ruby crown. The females don’t have them and the males are not always agitated. However if you keep watching, a bird may come close to watch you, then raise his crown when he figures out who you are. Maybe this curious ruby-crown is female.
Ruby-crowned kinglets are short-distance migrants that breed in spruce-fir forests in Canada and the northern/mountainous U.S. They spend the winter in southeastern Pennsylvania but are rare in western PA outside of migration. October is the time to see them in Pittsburgh.
Learn about these energetic birds in an 8-minute video by Lesley The Bird Nerd. Watch for the wing-flicking!