This is a REALLY helpful post dzyg. I thank you for posting it and hope that many people view it. This is a perplexing ID issue which many of us have endured. I just did some research on this very issue, and I came across a cool webpage which helped me a lot with this. It mentions the brown cheek patch of the male House Finch as an ID clue. This was helpful to me. http://www.birdzilla.com/bird-identification/id-skill-development/id-challenges/red-finches.html

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.

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.

It's illegal to move native bird nests, which probably includes incomplete nests.. According to Wikipedia : "Nests are made in cavities, including openings in buildings, hanging plants, and other cup-shaped outdoor decorations. " I honestly don't think they would mind that much, but it's best to keep your activity to a minimum once the eggs are layed/hatch.However, if it is really a bother, you should take it down..The female can built a new nest in 2 days anyway.. If you do let them nest,take it down once they fledge..This way, they don't reuse the nest..