California's tropical scrub (Porter and White 

 1973) up to 3,048 m in the California moun- 

 tains (Bond 1946) and 3,658 m in the Colorado 

 Rockies (T. D. Ray in Porter and White 1973). 



Most eyries in Utah are located near marshes 

 or streams which supply waterfowl or passerine 

 birds for food. Most eyries all on east-and-north 

 facing cliffs suggesting orientation away from 

 exposure to overheating by afternoon sun (Porter 

 and White 1973). Combination of marshes ad- 

 jacent to suitable cliffs for nesting may be con- 

 sidered an "ecological magnet" (Hickey 1942). 



In Alaska, habitat is in river valleys in boreal 

 forest area up to 800 m elevation. Western Can- 

 ada habitat varies from boreal forest to open 

 deciduous forest to arid types. In the lower 48 

 states, it varies from closed or semi-closed decidu- 

 ous forest in the east to semi-alpine and arid desert 

 in the west, usually overlooking water areas. In 

 Mexico, it is mainly along main cordilleran sys- 

 tems (King in press). 



FOOD AND FORAGING BEHAVIOR 



Its diet is mostly birds. Peregrine nestlings in 

 Alaska prefer birds to mice (Dixon 1908). Birds 

 eaten range in size from mallard ducks down to 

 warblers and nuthatches. Pigeons, flickers, jays, 

 meadowlarks, and other birds of medium size 

 probably constitute the bulk of food in inland loc- 

 alities; on the seacoast and islands, it feeds almost 

 entirely on the smaller seabirds. Mammals form an 

 insignificant part of their food. Remains of hares, 

 rabbits, woodchucks, squirrels and field mice have 

 been found near peregrine nests. They prefer to 

 capture prey on the wing after diving from above 

 at great speed. The highest speed attained by diving 

 is estimated at between 240 and 320 km per hour 

 (Bent 1938). Small prey is seized in its claws and 

 carried away; larger birds are stuck with the feet 

 with such force as to kill them. Then peregrines 

 descend to the ground to eat them. They pluck 

 birds, at least partially before eating. The male 

 feeds the female during the nesting season by drop- 

 ping food for her to catch in the air (Bent 1938). 



Food of Yukon River, Alaska Peregrines in 

 1966 included 49 species of birds and 4 species 

 of mammals. Waterfowl constituted 50% oi the 

 diet composed by weight, and shorebirds 10% to 

 12%; small land birds composed 20% and small 

 mammals 2% to 3%. Analysis of peregrine tissue 

 showed that the food chain was contaminated 



with significant measurable quantities of chlorin- 

 ated hydrocarbon pesticides in 1966 (Cade et al. 

 1968). In Utah eyries 79% of food identified con- 

 sisted of: American avocet (most frequent), 

 mourning dove, wUlet, western meadowlark, red- 

 shafted flicker, Wilson's phalarope, rock dove 

 (common pigeon), red-winged blackbird and 

 Brewer's blackbird (Porter and White 1973). 



Food of peregrines of Chihuahuan Desert and 

 adjoining mountains included 24 species of birds, 

 5 species of mammals (3 bats and 2 squirrels) and 

 1 species of lizard. Particularly frequent food 

 items were dowitcher (sp.), white-winged dove, 

 band-tailed pigeon, mourning dove, common 

 nighthawk, white-throated swift, common 

 flicker, Steller's jay, mockingbird, and thrush 

 (sp.) (Hunt 1976;Johnson 1976). 



In certain areas bats compose a greater part of 

 the diet than in others (Stager 1941). 



SHELTER REQUIREMENTS 



Cliff ledges for nesting and for night roosting 

 of young after they have fledged (Hickey cc? 1969). 



NESTING OR BEDDING 



Nest site chosen by female, who makes a 

 smooth well-rounded scrape in the accumulated 

 soil and rubbish on the cliff ledge, 2 or 3 cm 

 deep on the cliff ledge, to receive the eggs Q. A. 

 Hager in Bent 1938). Occasionally nests in broken 

 tops of tall trees (Ridgway 1889; Goss 1878; 

 Spofford 1942). 



Cliffs are by far the favorite nesting sites, but 

 cut banks, ledges of tall buildings, hollows in trees, 

 and tree nests of other large birds such as ospreys, 

 are also utilized occasionally (Hickey and Ander- 

 son in Hickey ed 1969; Porter and White 1973). 



RITUAL REQUIREMENTS 



Aerial courtship display centered about the 

 home cliff in March, consisted of the male flying 

 excitedly from shelf to shelf, with much vocaliza- 

 tion, in presence of female, bringing of food by 

 male to female and then intricate aerial flight by 

 male with vertical loops, rolls and plunges from 

 great heights. After some time, both male and fe- 

 male engage in scratching about on ledges accom- 

 panied by vocalization until finally eggs are laid 

 in one of the ledge sites Qoseph Hagar in Bent 

 1938). 



