Scientific name: Regulus calendula
With a seemingly outsized breeding range for such a small bird, the Ruby-crowned Kinglet nests across much of Canada and parts of the western U.S. Weighing only about one-fourth of an ounce, the Ruby-crowned Kinglet is indeed tiny. Its well-hidden and highly placed nests are hard to find, so much remains to be learned about its nesting ecology.
Ruby-crowned Kinglet nests are only rarely parasitized by Brown-headed Cowbirds, perhaps because cowbirds have a hard time finding their nests just as humans do. The record known lifespan of a Ruby-crowned Kinglet is just five years. Colliding with tall antennas during migration is one source of mortality.