and white-tailed jackrabbits (Lepus townsendii). As well as several species of geese, probable cygnets of Bewick's swans (Cygnus columbianus bewickii) as well as adults of the following: western capercaillie (Tetrao urogallus) (of both sexes), greater sage-grouse (Centrocercus urophasianus) and yellow-billed loons (Gavia adamsii). At the other end of the scale, the snowy owl has been known to take birds down to size of dark-eyed juncos (Junco hyemalis) and mammals down the size of common shrews (Sorex araneus). Fish are rarely taken anywhere but the snowy owl has been known to prey upon Arctic char (Salvelinus alpinus) and lake trout (Salvelinus namaycush). Interspecific predatory relationships The snowy owl is in many ways a very unique owl and differs from other species of owl in its ecological niche. Only one other owl, the short-eared owl, is known to breed in the High Arctic. However, the snowy owl shares its primary prey, the brown and collared lemmings, with a number of other avian predators. In sometimes differing parts of the Arctic, competing predators for lemmings are, in addition to short-eared owls, pomarine jaegers (Stercorarius pomarinus), long-tailed jaegers (Stercorarius longicaudus), rough-legged buzzards (Buteo lagopus), hen harriers (Circus cyaenus), northern harriers (Circus hudsonius) and generally less specialized gyrfalcons (Falco rusticollis), peregrine falcons (Falco peregrinus), glaucous gulls (Larus hypoboreus) and common ravens (Corvus corax). Certain carnivorous mammals, especially the Arctic fox and, in this region, the ermine, are also specialized to hunt lemmings. Most of the lemming predators are intolerant of the competition given the scattered nature of lemming populations and will displace and/or kill one another given the chance. However, given the need to conserve energy in the extreme environment, the predators may react passively to one another. When unusually breeding south in the Subarctic such as western Alaska, Scandinavia and central Russia, the number of predators with which the snowy owls are obligated to share prey and compete with may be too numerous to name. The taking of the young and eggs of snowy owls has been committed by a large number of predators: hawks and eagles, the northern jaegers, peregrine and gyrfalcons, glaucous gulls, common ravens, Arctic wolves (Canis lupus arctos), polar bears, brown bears (Ursus arctos), wolverines (Gulo gulo) and perhaps especially the Arctic fox. Adult snowy owls on the breeding grounds are far less vulnerable and can be justifiably qualified as an apex predator. Instances of killing of adult snowy owls