predation would be expected to be most important as habitat size and herbaceous cover within sagebrush decreases. A decline in preferred prey may also result in increased predation on greater sage-grouse. In southeastern Oregon, a decline in black-tailed jackrabbit (Lepus californicus) numbers may have caused predators to switch to greater sage-grouse as their primary prey. Predator species include coyotes (Canis latrans), bobcats (Lynx rufus), American badgers (Taxidea taxus), falcons (Falconidae), and hawks and eagles (Accipitridae sp.) prey on adult and juveniles. Crows and ravens (Corvus sp.) and magpies (Pica sp.) consume juvenile birds. Coyotes, ground squirrels (Sciuridae spp.), and badgers are the most important mammalian nest predators. Among bird species, magpies and ravens commonly prey on Greater Sage-Grouse nests. Greater sage-grouse are a popular game bird. Mortality due to hunting is generally considered to be compensatory and replacive, where until mortality reaches a "threshold value", it has no effect on population levels. Data are not available to suggest that closed or restricted hunting seasons will materially affect overall population levels on their primary range. In a study on hunting in a low-density greater sage-grouse population in Nevada, low populations may be a result of factors other than hunting. Protecting one greater sage-grouse population from hunting while doubling the birds harvested in a four-year period on another population showed, despite low recruitment, both populations increased to nearly the same density. In an Oregon study, no relationship was found between the rate of summer recruitment (chicks/adult) and harvest by hunters, nor was any significant relationship found between the size of the fall harvest and population trends during the subsequent spring. Conservation Residential building and energy development have caused the greater sage-grouse population to decline from 16 million 100 years ago to between 200,000 and 500,000 today. This species is in decline due to loss of habitat; the bird's range has shrunk in historical times, having been extirpated from British Columbia, Kansas, and Nebraska. Though the greater sage-grouse as a whole is not considered endangered by the IUCN, local populations may be in serious danger of extinction. In May 2000, the Canadian Species at Risk Act listed the subspecies Centrocercus urophasianus phaios, formerly found in British Columbia, as being extirpated in Canada. The presence of subfossil bones at Conkling Cave and Shelter Cave in southern New Mexico show that the species was present south of its current range at the end of the