House finches, weathertop

I have to admit to a certain amount of confusion here, but, then again, I know I'm not alone in being uncertain about the difference between a House Finch and a Purple Finch. They're tricky to tell apart—any honest birder will tell you that—and it's even tougher in the winter, when they're not in their fairly distinctive breeding plumage. Still, based on a number of characteristics, I'd put these in the House Finch camp, and that was a startling possibility. Carpodacus mexicanus used to be exceedingly common around here, and though it was really an invasive species—it's a westerner that moved into the territory of our native Purple Finch—it was tolerated because it had good habits and a fine voice. But about 20 years ago, birders noticed that many House Finches had conjunctivitis, a disease that often proved fatal, since it rendered the birds easy targets for predators and unable to find food effectively. All too soon, C. mexicanus vanished. If I'm right about the ID, this small flock of House Finches I discovered in the back woods represents a reinvasion. Their eyes look good. I wonder how soon they'll show up at the feeder.