Hummingbirds and the Limits of Knowing

It happens every year about this time. I’m minding my own business at the hummingbird feeders, and suddenly there appears a feisty little orange male with a solid green back: Allen’s Hummingbird! Or is it…?

This morning’s mystery bird popped up during an Aimophila Adventures Hummingbird Workshop at Beatty’s Miller Canyon Guest Ranch, probably the single best site north of Mexico to study hummers. We’d intended to head straight up the hill for the “fancy” species, but the feeders along the fence at the public reception area wouldn’t let us go. Among the numerous Black-chinned and Anna’s Hummingbirds were goodly numbers of Broad-billed and Rufous, with a few Magnificent (suitable name indeed!) and Broad-tailed Hummingbirds and at least one female Calliope. A male White-eared Hummingbird joined the crowd, too, a minor surprise at that elevation (we had up to 3 individuals at the higher feeders, along with Blue-throated Hummingbird to get us up to double digits).

And then, suddenly, a fully gorgeted, rusty-rumped and rusty-crowned little guy with a solid green back. Allen’s Hummingbird is an extremely low-density migrant through southeast Arizona, generally detected only by recreational banders measuring the tail feathers of the Selasphorus they capture. For the rest of us, it is pretty maddening trying to see the narrow outer rectrices of Allen’s and the nipple-like projections on the second-to-innermost pair of Rufous. Strictly speaking, only red-backed Rufous Hummingbird males are identifiable to species, all others simply Allen’s/Rufous.

But this is when I turn into a lister. To the workshop participants, I said ”Apparent phenotypic male Allen’s-type Selasphorus on the fence.” To myself? “Yippee!”