Dark-eyed Junco

Over the weekend I saw a couple of birds with black heads foraging for seeds under the feeder with the usual contingent of House Sparrows and House Finches.  The only black-headed birds I know that are regularly around here are the Black Phoebes, but this clearly was a seed-eater, not a fly-catcher.

So I got out the camera (which I've admittedly let sit dormant for longer than I like) and set up the tripod in the front room. The next day, they were back and I was able to get some pictures.  The National Geographic Field Guide to Birds of Western North America said this was the Dark-eyed Junco, and who am I to argue?

Here is a mature adult with a sprouted seed in his mouth.  These are ground-feeding birds, like the White-crowned Sparrows that have also been visiting us lately (more on them later), so they hop around under the feeder looking for stuff that's fallen from the feeder hanging above.

Dark-eyed Juncos are highly variable in their plumage, I've been led to understand. Wikipedia says they show a "confusing" amount of variation.  So I'm including the picture of this one just to show the similar dark cap, but in a much duskier tone. I think this one is a juvenile that is almost fully mature, based on the very faint stripes you can still see on its head.  Its more hoary coloring makes it look deceptively old, to me at least.

This one is a female. She's just a hair smaller than the mature males and obviously shows the more muted colors that seem so prevalent among female birds. Telling the mature males from the females is easy. It is often harder to distinguish juvenile birds from females. I'm learning that adult females will generally have smooth and muted version of the male coloring where juveniles generally show striped plumage. I assume (and haven't bothered to look it up) that juveniles are more camouflaged, particularly in trees and nests. There is evolutionary advantage for immature juveniles that are better able to blend into their surroundings in that they are less likely to be seen and eaten. Mature birds have two competing evolutionary forces at work - avoiding predation and attracting a mate. With a lot of males, the pressure to be pretty seems to prevail over the pressure to hide.

Here are a couple more shots of a fully mature male.  Juncos are apparently very common (although I barely knew they existed until this weekend), so you are likely to see them pretty much anywhere in North America.   Because they show so much variation, the Dark-eyed Juncos in other parts of the country might not look like these, which I am pretty sure are the Oregon form.

Dark-eyed Junco, January 6, 2013, in my yard. Shot with Nikon and Sigma lens.