Snowy owls normally live their lives in the endless summer sunshine and perpetual winter darkness of the high Arctic. But every once in a while, for reasons that are not fully understood, snowy owls come flooding down from the north in a phenomenon known as an irruption.

Smaller irruptions happen every few years, but once or twice in a lifetime a mega-irruption occurs, when snowy owls show up much farther south, and in vastly greater numbers, than usual.

This winter, 2013-14, is one such extraordinary event, the largest irruption in the Northeast and Great Lakes regions in four or five decades. Snowy owls have been reported as far south as Florida and Arkansas, and even on Bermuda.

It's interesting to track an owl's movement. Here is Assateague. Click 'next'.