In the field guide, it’s called a fieldfare.

In the bird-watching world, it’s a Code 4 event.

“It kind of blows your mind to have one in Missoula,” Five Valleys Audubon Society board member Jim Brown said of the robin-sized bird’s sighting during last weekend’s Christmas Bird Count. “If you bird all your life, you might get a Code 4 bird. If you chase rare birds and have a bunch of money, this is one where you’d get on a plane to fly out there to see it.”

In fact, the crowd of binoculars-toting birders cruising around Harper’s Bridge off Mullan Road on Monday included one couple who’d driven over from Idaho to see the fieldfare, and a man from Helena who’d dropped his family at the mall while he tried to make a major notch in his life list of birds seen. The Idaho couple went home happy.

The fieldfare looks like a robin with black speckles on its breast instead of solid red-orange coloring. It likes the same kind of habitat – fruit trees and berry bushes – only in Norway and Sweden and Russia.

“There was a tremendous low-pressure system off Siberia that buffeted the Alaska coast last week,” Brown said. “That may be what got it to our side of the world, although why it came this far inland, I don’t know. There have been reports of fieldfares in eastern Canada and the eastern United States, where it’s easier to get blown across.”

The American Birding Association notifies members of interesting sightings by a code ranking. Codes 1 and 2 refer to widespread and difficult to find, respectively. Code 3 birds are rare but make annual visits to an area. Code 4 birds are “species not recorded in the ABA checklist area, but with six or more total records including three or more in the past 30 years.”

Code 5 is “accidental” with fewer than three records in the past 30 years. Code 6 is “probably or actually extinct or extirpated from the ABA checklist area.”

The Audubon Society’s 54th annual Christmas Bird Count inspired about 35 groups of birders to spend last weekend recording all the different species they could spy in and around Missoula. They reported about 70 species, including a pair of wildcards. Besides the fieldfare, birder Sue Reel reported a rare surf scoter (also known as a skunk-headed coot) along the Bitterroot River near Fort Missoula.

“That’s an oceanic bird that when it migrates south, some get caught up in the wind and bend over to Montana,” Brown said. “It’s a big black duck, with a big bill and a sloping profile. There were a few surf scoters earlier this fall at Browns Lake (near Ovando).”

Five Valleys Audubon spokeswoman Poody McLaughlin said the fieldfare sighting has already made waves on the American Birding Association’s blog and other networks. She got to see it herself, which she called a once-in-a-lifetime opportunity.

“This is like a meteor landing in Missoula’s bird world scene,” McLaughlin said. “I hope it hangs out all winter. But it’s not necessarily buying real estate in Missoula, so if people want to see it, they better try as soon as possible. Who knows how long it might last?”