Male Purple Finch.
While humans dither over global warming, many American bird species are making their move. The National Audubon Society has looked over the past century of Christmas Bird Count records. And it is clear that hundreds of bird species are wintering further and further north. The champion mover seems to be the Purple Finch, now found over four hundred miles north of its wintering grounds four decades ago. The Wild Turkey has also moved four hundred miles north. Along the Pacific Coast the Marbled Murrelet is abandoning the southern portion of its range and moving northward as well.
Some birds are not as adaptable and may face diminished range and even extinction as global warming continues.
Here in Southern Oregon we're now seeing Tree Swallows in the dead of winter. Some breeding birds have moved north from California and are here year round: Red-shouldered Hawk, White-tailed Kite, Mockingbird.