Tuesday, January 17, 2012

Snowy Owls Invade Idaho

My friend Beth Rasgorshek speaks eloquently and often about the importance of protecting farmland. She grew up on a Canyon County farm and returned here to start her own.

Her Canyon Bounty Farm produces organic seeds, heirloom vegetable starts for area gardeners and organic wheat flour used in several local bakeries and restaurants. She believes in growing good food, and that Canyon County is a great place to do just that.

But the development is hard to ignore. Homes and buildings ominously close in on her farm from all directions. Soaring land prices make it difficult to keep farmland in production. Beth knows Canyon County land also has deep values for food production and open space.

So too does another unusual visitor, here all the way from the Arctic: snowy owls.

For the past few weeks, several of these beautiful owls have been spending their days on farm fields near Nampa. Usually at home among polar bears, what are they doing here?

Snowy owls are usually found only in the Arctic, where they forage on a variety of rodents, but most especially lemmings. In that age-old dance of predators and prey, lemming populations determine much of the snowy owl's abundance and movements.

Lemming are small rodents that are prone to wide population swings. This is similar to population eruptions of other rodents, including the montane voles that periodically explode in numbers around Silver Creek Preserve (including a notable abundance in 2010).

Many people know lemmings as the creatures that build up to such extreme numbers that they run in swarms towards cliffs, where they "commit suicide." This is a false myth generated by an old Disney film. It was later revealed that filmmakers staged the "suicide scene" by gathering a relatively small number of lemmings and herding them over the cliff.

But lemmings do migrate (sometimes falling off cliffs, but accidentally and in small numbers) and certainly become super-abundant. Snowy owls feast on them, and eat about three of these rodents per day. When lemming populations crash, snowy owls must travel south to find good rodent foraging, an event called an owl irruption.

Biologists report healthy lemming populations this year. It appears, though, that this led to an increase in snowy owl chicks. Many young birds couldn't find their own territory, so they flew south to an unfamiliar land of agricultural fields, subdivisions and people.

A few of them ended up in Canyon County. Area birders say that some snowy owls show up there whenver there is an irruption.

This past weekend, a group of friends joined Beth, who had been seeing them near her farm. We found an owl rather easily, as there was a line of cars watching it in the middle of the field.

Snowy owls roost on the ground, and this one was easy to see on the bare earth. The white plumage is definitely more suited to the snowy Arctic than snow-free (at this writing) southern Idaho. The owl stood out--almost resembling a white plastic bag from a distance. With a spotting scope, we managed great views.

The owls are a major attraction for birders. One California birder was skiing at Targhee, in eastern Idaho, and drove across to see these owls.

If you go on your own snowy owl quest, please give these birds plenty of space. They're not used to people. Some biologists say that most snowy owls have seen more polar bears than people.

The ones you'll find in southern Idaho are likely young birds, so they need some room to learn to hunt and figure out the unfamiliar prey of Idaho fields.

Please, please, please do not try to get close to them to get a better photo. Enjoy them at a distance, and use binoculars, spotting scopes or telephoto lenses to get closer--not your feet.

The snowy owls will likely stick around for a few weeks before returning to their Arctic wilderness. In the meantime, let's make sure they feel at home on our area farmland, and let's also recognize the tremendous value these farms provide--for wildlife and for people.--Matt Miller

Photos: Beth Rasgorshek checks out owls. Credit: Matt Miller. Snowy owl photo by pe_ha45 licensed under the Creative Commons Attribution 2.0 Generic license

1 comment:

Gary E Peebles said...

Hey, Matt and group. It was a pleasure to help out with the sighting of the Snowy owl. This is a great article. I am also a member of the Nature Conservancy. Small world isn't it.
Gary Peebles, Birder, skier and lover of the wonders of nature.