I don't know what got them, but the squirrels here have gone nuts. They act like they are starving to death. They chewed two holes in my deck box and it is thick. They try frantically to jump to my window feeders all day long. Chewed a hole in my screen. I finally had to take the feeders down. I really hate that. I had them there last year and the squirrels didn't bother them. I could watch hummers, woodpeckers and finch who sat 3 ft away. There are more birds this year also. I was wondering if the the winter weather is causing the squirrels to act like they are starving. I have fed birds and squirrels for years and never seen squirrels like this.

That smaller egg is definitely a Cowbird egg. I got in a HEAP of trouble a few weeks back when I was trying to get some advice on this subject (see the reg. birding forum under "Cowbird Egg in Finch Nest - probably on about pg. 3 by now, for the fracas...), so tread very carefully. I - how shall I say - "took care of" the egg in question. Only you can choose what to do with your interloper egg, but be ready to get flamed by most of the GW birding world for your "illegal, unethical, criminal, (et al)" behavior if you mention it here.

Interesting. I knew Brown headed cowbirds could not be raised by Goldfinches because they feed their young seeds, but I didn't know House Finches did also. I looked it up at Cornell's lab of ornithology, and they confirm what you have read. I guess that means you don't have to worry about the young House Finches. I've also read about retaliation from the Cowbirds, so I guess just leaving it there should protect the baby House Finches best.

The female House Finches incubate the eggs-maybe she died and the male is trying to fill in? In any case, this introduced species (they're from the West) is tough enough to evict House Sparrows, so House Finches are in no danger and considered pests by many. Still they are pretty and endear themselves to some because they like to nest very close to people.