Rising temperatures push North American birds to the far north

BIRDS usually fly south to warmer regions in winter. But birds in North America were found moving north to colder climes in early winter. Audubon Society, a leading US-based advocacy group for conserving wildlife and ecology, reported this unusual change in migratory patterns in February 2009 after a study over four decades.
More than half the 305 bird species in North America including robins, gulls and owls were found spending winters farther north during the Society