Parasitic Birds

So, for the last month or so I've been watching this Oregon Junco take care of a bird that was clearly not a close relative.  The Junco is a very pretty little bird and the bird that it was taking care of was half again as large and while clearly in juvenile feather making it difficult for me to identify, was definitely not going to be a Junco.

My brain finely engaged and I remembered that Brown Headed Cowbirds, of which there are many around here,  are nest parasites.  They will remove an egg from the chosen host and replace it with one of theirs.  Then the chosen host will take care of the fledgling as though it is their own.  This is the first time I've actually witnessed it.  I'll tell you what though, that little Junco is taking excellent care of it's, uh, adoptive child.  LOL.  Hope the pictures are clear, I had to use a lot of zoom and they do blend well into the ground.  Hmm, I wonder when the Cowbird figures out it's a Cowbird and does the Junco ever have a clue that this isn't it's kid?  Ah, nature.