You can also tell a finch by it's song...we had two types when I was younger...I forgot to add them in my "how many pets have you had" poll......anyway, we had zebra and another type...the other type we had had orangish eye feathers and silvery gray bodies...finches tend to make a lot of noise...does this bird do this? I just realized you may not know because he/she is alone...

Here's a link of bird care...hopefully this can help in what to do as far as food, etc. Bird Care