The ruby-crowned kinglet is a very small bird, being 9 to 11 cm (3.5 to 4.3 in) long, having a wingspan of 16 to 18 cm (6.3 to 7.1 in), and weighing 5 to 10 g (0.2 to 0.4 oz). It has gray-green upperparts and olive-buff underparts.

Do ruby-crowned kinglets flock?

It often hovers while gleaning and sometimes darts out to catch insects in mid-air. From fall into spring, the Ruby-crowned Kinglet often joins small feeding flocks with other woodland birds, including the Downy Woodpecker, Yellow-rumped Warbler, and White-breasted Nuthatch.

What does a Ruby-crowned Kinglet look like?

Ruby-crowned Kinglets are olive-green birds with a prominent white eyering and white wingbar. This wingbar contrasts with an adjacent blackish bar in the wing. The “ruby crown” of the male is only occasionally visible. ... Ruby-crowned Kinglets breed in tall, dense conifer forests such as spruce, fir, and tamarack.