Bird Identification: CLOSED: Mystery Bird - Help Needed, 1 by ChirpChirp

ChirpChirp wrote:
I spotted this small bird in my yard in NY state a short while ago and I can't seem to identify it. It was a little bigger than a sparrow, and when it flew around I noticed under the inside of its wings were a vibrant red, you can just see on the pictures. I've not seen it before and it seemed to be just hopping amongst the undergrowth peeking its head out. Is it a juvenile of something?

Any help very much appreciated.