(n.) One of several species and varieties of large Arctic falcons, esp. Falco rusticolus and the white species F. Islandicus, both of which are circumpolar. The black and the gray are varieties of the former. See Illust. of Accipiter.
Example Sentences:
(1) Tundra peregrine eggs contain an average of 889 parts of DDE per million (lipid basis); taiga peregrine eggs contain 673 parts per million; Aleutian peregrine eggs contain 167 parts per million; rough-legged hawk eggs contain 22.5 parts per million; and gyrfalcon eggs contain 3.88 parts per million.
(2) Eggshell thickness after exposure to DDT was reduced by 21.7 percent in Alaskan tundra peregrines, by 16.8 percent in taiga peregrines, by 7.5 percent in Aleutian peregrines, by 3.3 percent in rough-legged hawks, and not at all in gyrfalcons.
(3) A 2-year-old female gyrfalcon (Falco rusticolus) was being used to hunt ducks in southeastern Wyoming during an outbreak of avian cholera in waterfowl and wild turkeys.