This time last winter, Snowy Owls irrupted across the northern U.S., particularly the east and Midwest including Philadelphia. And biologists took the chance to outfit the birds with tracking devices. You can read about the surprising things they learned via Species on the move: Snowy Owl : BirdCast. “As of mid-November, snowy owls had been […]
irruption
Breaking News: Red Admiral Irruption in the Northeast
Apparently, the Red Admirals are arriving in North America in record numbers. The butterflies are on their way north, up as far as Ontario, after wintering in Guatemala. When a species’ local population suddenly increases in size, the phenomena is called an irruption. The Red Admirals (Vanessa atalanta) usually begin to migrate in March and […]