Its head was completely caved in. If I didn't know better, I would accuse the house sparrow of feasting on it while in the box.
|Tree Swallows, Charles River Peninsula, Needham, MA|
Meanwhile, a pair of tree swallows are dangerously close to another house sparrow favorite, box 14. Here's hoping the sparrows' murderous impulses don't emerge.
In happier news, not one but two complete bluebird nests. Today's new migrant visitors: Eastern Towhee, Bluegray Gnatcatcher, Chipping Sparrow.