Chen rossii

Snow geese have arrived in northern Utah after traveling from their wintering grounds in Texas and other Gulf states. Birders are now enjoying them in fields in the Corinne area.

But not all of the geese in those fields are snow geese. Look closely at those "white" geese. If you see a smaller white goose with a pink bill and black wingtips, you've found the Ross's goose. It is a miniature version of the more abundant snow goose. It breeds in the central Arctic and winters primarily in central California.

The Ross's goose has a smaller population than its larger cousin, the snow goose, but its numbers are growing. This is a smaller goose with a wingspan of 22-25 inches and weighs between 2 and 4.5 pounds.

Ross's geese breed on the Arctic tundra and the downy young are either a yellow or gray color. Once mature, they show the characteristic white body with black primaries.

On rare occasions, a Ross's goose can be found in a dark morph phase, like the blue phase of its larger snow goose cousin. These morphs are believed to be hybrid offspring from Ross's/snow goose parings.

Because the Ross's geese are expanding their range eastward, there has been increased hybridization with the snow goose.

Incubation duties are performed exclusively by the female Ross's goose, with her mate performing as a guard while she is on the nest. The eggs are covered with down whenever the female leaves the nest to keep the eggs warm and protect them from view of predators.

Bill Fenimore is owner of the Layton Wild Bird Center, www.wildbird.com/layton, author of Backyard Birds of Utah and a member of the Utah Wildlife Board.

The Wild Bird Center is holding a free bird walk to see displaying wild turkeys March 26. The bird walk will leave from the Layton Wild Bird Center at 6 a.m.