I’m not conducting junco-focused field work anymore, but that doesn’t mean I’ve lost my fondness for the little guys. I was delighted this spring to find a junco nest not five meters from my front door, well-hidden in the crotch of an ornamental tree.
Readers who have been with me a while will remember “Buddy,” the white-spotted male junco who lived near my workplace for years. Unusually-colored juncos aren’t as rare as, say, the recently-spotted yellow cardinal, but they aren’t common either. (In my field work in the Sierras we banded ~500 juncos, and only one had a color abnormality.) As a lover of both rare birds and juncos, I get pretty excited about them when I find them.
This particular junco flashed up out of a bush as I was walking past. The size, tail, and movement pattern all said “junco”—but when the bird landed in a tree and I got a good look, my brain’s bird-ID function got confused: “Big chickadee!” it suggested. “Small kestrel! Big-small-chickadee-kestrel-junco!”
For birds, cleanliness is not optional. They rely on their feathers for flight and insulation, and only replace those feathers once or twice each year. In between molts, they need to keep their feathers as whole as possible.
Feathers, like our hair, are made of protein; and like all organic things, they degrade over time. Sunlight hastens this degradation, but certain aspects of the feathers themselves can slow it: dark feathers colored with melanin last longer in sunlight, for example. Of more concern, though, are the many creepy-crawly things that like to eat protein, and will happily hang out in a bird’s feathers, munching and laying eggs.
To combat these parasites, birds coat their feathers in protective oil from the preen gland located at the base of their tail, and they bathe.
But they have to be careful. Small wild birds are lunch for everything from feral cats to Cooper’s Hawks, and no bird wants one of these sneaking up on it while it is obliviously scrubbing behind its ears. So they bathe in bursts, a plunge into the water followed by a quick look around.
Did anybody see that?
Something is not quite right here. What is it?
I was supposed to be done with field work after summer 2015, but you know how it is. The birds call. You realize that a few more blood samples would put the patterns you’re seeing in context in an illuminating way. You miss those feathery little dudes.
The small amount of field work I did this year took place much earlier than my usual field work because I was sampling juncos at a much lower elevation. Down here, the juncos are breeding in mid-March. Up at my usual sites, they wait until late May. That early start happened to be convenient for me, since I needed to analyze any data I got in time to file my dissertation in mid-May.
This nest is a great example of juncos’ love of sloping ground. In some cases, like this one, the sloping ground is slope-y enough to call a wall. I wouldn’t call this a typical junco nest, but it’s not really surprising either: juncos are reliably creative with their nesting choices, which must make it difficult for predators to find them. This nest certainly seemed well-hidden—and it didn’t have to worry about being stepped on, either.
Juncos love to nest near corn lilies. Usually this means they nest near the base of the corn lily, using the thick stalk and broad leaves as cover. SEAL, however, decided that his nest didn’t need to be near an upright corn lily—and I have to admit that it’s not a bad idea: it took me an extra little while to find this nest, just because it didn’t look like a conventional junco nest location.