First Record of a Black-Legged Kittiwake in Idaho

Abstract

The Black-legged Kittiwake (Rissa tridactyla) is a common oceanic gull that winters off the Pacific coast from British Columbia south to northwestern Baja, California (A.O.U. Check-list 1957). While there have been several inland reports of Black-legged Kittiwakes in various western states (Haywood et al. 1976, Weber and Larrison 1977, and others), to our knowledge this species has never before been reported in Idaho. The purpose of this note is to document the first record of this species in Idaho and to review past records of the kittiwake in adjacent states. The carcass of a juvenile male Black-legged Kittiwake was found by the authors on 13 February 1980, approximately 5 km southeast of Howe, Butte Co., Idaho. The nearest large body of water is American Falls Reservoir, located on the Snake River, 85 km to the southeast. This bird appeared to have been dead less than 24 h. A large wound on the dorsal portion of the body, just behind the neck, indicated that the bird may have been killed by a raptor. The carcass weighed 277.5 g and contained no deposits of body fat. Most of the inland sightings of Black-legged Kittiwakes in the northwestern United States have been made in the last eight years (Table 1). It is unclear whether this recent increase in sightings is the result of greater effort by field biologists, or if it results from a pioneering tendency of the kittiwake due to an increase in the number of reservoirs along major northwestern rivers. Juvenile gulls of many species wander great distances in the late summer and fall (Pettingill 1970, Parsons and Duncan 1978). Since at least one of the records was for an adult and most of the sightings occurred during the winter and early spring, this does not immediately offer a satisfactory explanation for the majority of inland kittiwake records. Further, the sightings ofkittiwakes do not follow the same pattern as those of the Ancient Murrelet (Synthliboramphus antiquu ; Munger 1965); Munger indicated that murrelets wander inland primarily during October and November, and their movements are associated directly or indirectly with adverse weather over the Pacific coast. However, we found that at least one and usually a ser es of low pressure systems had moved inland across the Pacific Northwest within a twoto three-week period just before each inland kittiwake sighting (U.S. Dep. of Commerce) except for the 1898 sighting, for which we have no data. We suggest that inland movements by the Black-legged Kittiwake are often the result of winter storms moving inland from the Pacific coast.