Figure 103. First-year Gyrfalcons occur annually in Washington and Oregon but have been detected only ten times in California. This one was photographed on 10 November 1989 at Tule Lake NWR, Siskiyou and Modoc Counties (1989-125; Ray Ekstrom).

 

 

 

 

 

GYRFALCON Falco rusticolus Linnaeus, 1758

Accepted: 10 (83%)	Treated in Appendix H: no
Not accepted: 2	CBRC review: all records
Not submitted/reviewed: 2	Color image: none

This large, holarctic-breeding falcon is partially, and irruptively, migratory. In North America, the species winters irregularly south to the northern contiguous United States. Since the mid 1980s, small numbers have been found annually south into Oregon, mostly between late October and mid March but sometimes into April. The species occurs casually south as far as the central Pacific coast, southern Great Plains (exceptionally to northern Texas), central Midwest, mid Atlantic states, and Bermuda.

California’s first Gyrfalcon was a first-fall bird collected on 23 October 1948 two miles west of Lower Klamath Lake (not Tule Lake as in Roberson 1980) in Siskiyou County (Jewett 1949). More than 30 years passed before the next acceptable record. Each of California’s Gyrfalcon records has involved a first-year, gray-morph bird in the northern third of the state, each has occurred between 16 October and 20 February, and only two records come from coastal areas: 31 October 1993–20 February 1994 at the Smith River bottoms in Del Norte County, and 16 October–3 November 2003 at sites around Humboldt Bay in Humboldt County.

Gyrfalcons, and hybrids involving this species, are known to be kept by falconers. Observers are encouraged to consider these factors when documenting this species in California, and to search for bands or jesses that would indicate prior captivity.