The big talk right now on ID Frontiers Listserv is an unusual hybrid and for once, they don't mean gulls! Someone got photos of what looks like a blue tit hybrid...but what did it hybridize with? Chickadee? Titmouse? It's not a true blue tit. The photos were taken in New Hampshire and the bottom line is that we don't have blue tits in the US naturally. Every now and then the pop up--especially around Chicago. Rumor is that there's an exotic bird breeder and brings them in as pet birds (yep, European species are legal) and then they get released. There are reports of blue tits, great tits, and European goldfinches. We've seen them in Minnesota and Wisconsin and even Mr. Neil had a blue tit show up in his yard.
Some speculate that whoever is releasing them is trying to establish a US population--which is not a good idea because we don't know what could happen. If they hybridize with native birds, could we get a situation like we have with blue-winged and golden-winged warblers? And really releasing birds in an area where they weren't meant to be and are not prepared for surviving in it, is just down right cruel.