The bird is believed to be the first of its kind to get to the area, The Press-Enterprise of Riverside reported. Mark Chappell, a biologist at the University of California, Riverside, said gyrfalcons are spotted in Northern California every few years, but all recorded sightings have been at least 400 miles north of the current one.
The gyrfalcon was first seen Jan. 15 in the San Jacinto Wildlife Refuge. Chappell said at first he assumed what he had spotted was an unusually large peregrine falcon.
Gyrfalcons are the largest falcon. They have a circumpolar distribution with populations in the European, Asian and North American arctic.
While most gyrfalcons winter in the arctic, a few move south after the breeding season ends.
Jonathan Batkin, head of the Wheelwright Museum in Santa Fe, N.M., said he was in Southern California on business when he heard about the gyrfalcon and decided to take a few days off to search for it. He has seen it from about 100 yards away.
"It flushed a bunch of birds off a pond, the birds scattered and it climbed up until I lost it against the hills," he said. "It's really powerful and fast."