I’m finding dead Tree Swallows in the nest boxes I tend at a neighborhood golf course. I’ve got four dozen boxes, so the information I gathered by looking in six of them this afternoon isn’t necessarily definitive, but I think these cold wet days are the reason baby birds are dying. In one box were five birds near fledging size, all dead for at least two days. In a second box I found six birds perhaps a week old, not dead but barely moving when touched. Healthy birds would have been actively reacting to me as a deliverer of food. They’ll be dead by morning. Tree Swallows feed exclusively on insects they catch in the air. Cold, wet days aren’t good for that. There is one other interesting element to the swallow nests this year: they contain far more feathers than usual. You can easily distinguish a Tree Swallow nest from an Eastern Bluebird nest (both species use the boxes) by the presence of feathers in the swallow nests. Usually, there are two or three feathers, as you see in the first photo below, taken in 2005 (the nest was removed from the box for the photo). The second photo shows one of this year’s nests as seen in the box. It’s wrapped in feathers. Well-feathered nests stay warmer. Chicks in these nests grow faster and have lower frequency of parasites. None of that matters, though, if there is no food.

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