They sit in fields, dunes, and lakeshores like big white cats, unperturbed by cold snaps that leave bird watchers shivering and blowing on their hands. Snowy Owls visit the northern tier of states in most winters, but in rare years such as this one, they turn up in droves.

Irruptions seem to correspond with the lemming crop in the owl’s arctic breeding range—and it may be a case where feast turns to famine. In the long summer daylight, Snowy Owl parents hunt lemmings to feed their young. When these are plentiful, the owls can raise double or triple their normal number of chicks. Once autumn arrives, that horde of hungry youngsters has no choice but to fan out and head far south of the species’ normal range.

For winter fare, Snowy Owls may turn their big yellow eyes on birds, often eating waterfowl such as grebes, ducks, and auks. Look for them along shorelines or even harrying birds over the water.

With Snowy Owls turning up as far south as Missouri, this year may be your best chance to see one for a long while—check this eBird map to see if any are near you. Just remember to keep a respectful distance to avoid harassing the birds, which may be tired, hungry, and just trying to make it through their first winter. No luck outdoors? You can also spy these thrilling winter visitors in a short video from our Multimedia program.

—Hugh Powell