Appropriately enough for a day in which plans to despoil boreal forests were dealt a blow, the first hermit thrush of the winter showed up yesterday. These thrushes breed in the boreal and mixed forests of Canada and the western U.S., then move south for the winter. They are well-camouflaged against fallen leaves; even their rusty tail looks like a fallen autumn leaf. Once spotted, though, they are easy to identify: unlike other thrush species, the hermit thrush bobs its tail up and down, giving away its identify even when all other field marks are unclear.