The Status of Harlan's Hawk in Southern California

Harlan's Hawk, Buteo jamaicensis harlani, has had a checkered taxonomic history since its description by Audubon (1830) from two specimens collected in Louisiana.It has at times been considered a separate species, a subspecies of the Redtailed Hawk, Buteo jamaicensis, or perhaps even a local color morph or unique immature plumage of the latter rather than a distinct taxon.Ridgway (1890) suggested it be treated as a distinct subspecies of the Red-tailed Hawk, but it was still considered by some to be a separate species as late as 1959 (AOU 1957, Gabrielson and Lincoln 1959).Studies by Swarth (1926), Mindell (1983), and Snyder and Snyder (1991) have now established that harlani is best treated as the local subspecies of the Red-tailed Hawk in western, central, and south-coastal Alaska, southwestern Yukon, and northwestern British Columbia (AOU 1998).This view, however, is still not unanimous (Dunne et al. 1988).Harlan's Hawks make the longest migration of any of the several subspecies of the Red-tailed Hawk.Their path is east and southeast, passing over the ranges of a number of other subspecies (Mindell 1983, 1985), and they winter among individuals of the subspecies calurus, borealis, and krideri.The winter range of harlani is largely in the southern Great Plains from Kansas, southern Missouri, and Arkansas south to Texas and Louisiana (AOU 1957, Lowery 1974, Oberholser 1974); harlani may occur in northeastern Mexico in winter (Howell and Webb 1995).Individuals have been recorded as far east as Pennsylvania (Todd 1940) and Mississippi (AOU 1957) and west to California (Grinnell and Miller 1944, Small 1994, Garrett and Dunn 1981) and Washington (Lavers 1975).The type specimen of Buteo cooperi, collected near Mountain View, Santa Clara County, California, is also referable to harlani (Grinnell 1930).In northern California, Harlan's Hawk is a rare but regular winter visitor, particularly in the Sacramento Valley and northeastern California (Grinnell and Miller 1944, Small 1994, T. Manolis pers.comm.).In southern California there are sight but no specimen records, from San Luis Obispo County south to Imperial County, mostly east of the coastal zone (Garrett and Dunn 1981, K. Garrett pers.comm.).In Orange County there are winter sight records of two individuals from the Plano Trabucco and Upper Newport Bay/San Joaquin Marsh (Hamilton and Willick 1996) and a recent sighting in Yorba Linda on 4 February 1998 (J.Kidd pers.comm.).Other recent sight records are of a dark individual with extensive white chest markings and very white tail seen 20 November 1994 in the Puente Hills near Whittier, Los Angeles County, and the same or very similar bird seen 18 February 1996 at Prado Dam on the Santa Ana River, Riverside County (J.Schmitt pers.comm.).On 1 March 1990 an adult Harlan's Hawk was found shot at the Oak Canyon Nature Center in Anaheim Hills, Orange County.Attempts to rehabilitate it were unsuccessful.This specimen, the first for southern California, is number 7812 in the collection of California State University, Long Beach.An adult female, it had a regressed ovary and measured as follows: wing 393 mm, tail 212 mm, tarsus 95 mm.The tips of the outer primaries are badly broken, possibly due to its time in captivity.Although on the small size, the measurements for tail and tarsus are within the range given for female harlani by Oberholser (1974).This bird is in the first adult dark-morph plumage (i.e., second basic) with retained juvenile outer ninth and tenth primaries and two to four secondaries.It exhibits the 200 Western Birds 31:200-202, 2000

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