I have a shelter logic shed for my golf cart. Recently I found this nest built on one of the upper supports of the shed. Today I saw that it was a phoebe's nest. I got a picture with my phone from above it, and this is what I found. Of course I immediately assumed it was a cowbird's egg, but I've never seen them so bluish-green. Do any other birds do that? I'm thinking they don't. Can cowbird eggs vary in color like that? I hope I don't scare the phoebe away with my coming and going out of the shed. As she flew out of the shed to a nearby tree, I told her she has nothing to fear from me, but I'm not sure she was listening. :)