Volume 27, number 1 of Western Birds, published 1996
This article reports on the review of 253 records of 96 species by the California Bird Records Committee (CBRC). Of these, 219 were accepted (86.6% acceptance rate). This rate is higher than in recent reports, due to an unusually large number of accepted records of passerines normally from the southeastern U.S. during spring 1992. It includes records from 1954–1993, with most from 1992.
Vaux’s Swift (Chaetura vauxi) is a migrant breeding from the western U.S. to northern Venezuela, wintering from central Mexico to Venezuela (AOU 1983). In 1994, the California Department of Fish and Game designated it as a “species of special concern.” Its breeding biology and habitat requirements are poorly known but are thought to be linked to old-growth forests (Lundquist and Mariani 1991; Bull and Hohmann 1993).
Fragmentation of old-growth forests and its effects on bird distribution in the western U.S. is a major issue (Harris 1984; Thomas et al. 1990). Most research on this topic focuses on the ecology of the Spotted Owl (Strix occidentalis), Marbled Murrelet (Brachyramphus marmoratus), and Pileated Woodpecker (Dryocopus pileatus), while other species like the Vaux’s Swift receive relatively little attention (Carey 1989; Ralph et al. 1991; Huff and Raley 1991).
The Spruce Grouse (Falcipennis canadensis; see below for use of generic name) consists of two groups of subspecies, those with white-tipped upper tail coverts and lacking a chestnut tail band (the franklinii group) and those without white tipping but with a chestnut tail band (the canadensis group, see Figure 1). The first group, up to now composed of only the subspecies franklinii, was until recently represented from Alaska by only a single museum specimen, an adult female taken by Wilfred H. Osgood on Prince of Wales Island in the Alexander Archipelago on 27 May 1903 (unpublished data in Smithsonian Institution archives). A second specimen, a male, was taken on the island by Paul Coffey on 14 September 1982.
The migration of Turkey Vultures (Cathartes aura) is not nearly as well studied as that of many species of raptors. Raptor migration counts are conducted annually at numerous locations throughout North America (Kerlinger and Gauthreaux 1985, Heintzelman 1986, Kerlinger 1989). Count sites are generally located along mountain ridges or coastlines where migrating raptors congregate (Kerlinger and Gauthreaux 1985, Kerlinger 1989). Both raptors and vultures migrate by day, taking advantage of thermal updrafts. However, sites that provide good conditions for migrating raptors, or for raptor viewing, do not necessarily provide optimal conditions for migrating vultures. Indeed, large flights of migrating vultures (i.e., >5000 individuals) are rarely recorded at hawk-watch sites.
The Gray Vireo, Vireo vicinior, winters mainly in coastal Sonora (including Tiburón and San Esteban islands) and sparsely in southern Baja California, southern Arizona (mountains of Yuma and western Pima counties), the Big Bend region of western Texas, and probably southwestern Coahuila (Phillips et al. 1964, Barlow and Wauer 1971, AOU 1983, Phillips 1991, Howell and Webb 1995). We report here a recent record of the Gray Vireo from the state of San Luis Potosí, México, and suggest that the winter distribution of the Gray Vireo may be more widespread than is currently recognized.