The Peregrine Falcon Release Program in Hull 
Bruce M. Di Labio and Charles Dauphine 
Canadian Wildlife Service 
Introduction 
The anatum subspecies of the Peregrine Falcon (Falco pere- 
grinus ) has been the object of one of the most intensive efforts 
to re-establish a bird endangered with extinction in North 
America. From the late 1940s to the mid-1960s, the anatum 
peregrine rapidly disappeared from most of its vast range east 
of the Rockies and between the tundra and the Gulf of Mexico 
(Fyfe 1976a). Persistent organochlorine chemicals, such as 
pesticides like DDT, accumulated in the peregrine's food chain 
and, once concentrated in the peregrine's body, inhibited its 
reproduction (Hickey 1969). By the time the use of organochlor¬ 
ine pesticides came under tight restriction in North America in 
the early 1970s, the peregrine had ceased breeding at all of its 
known eyries (nest sites) east of the Mississippi and in central 
and eastern Canada (Cade and Fyfe 1970). 
In 1970, wildlife administrators in Canada urged the Cana¬ 
dian Wildlife Service to collect some specimens from the surviv¬ 
ing wild population and breed them in captivity. Having too 
small a residual population with which to work, scientists in 
both the United States and Canada believed that a captive breed¬ 
ing and release program was the most feasible way to seek the 
species' recovery. Canadian Wildlife Service scientists devel 
oped a method for breeding peregrines in captivity and began to 
produce young for release into the wild at a special facility^at 
Wainwright, Alberta (Fyfe 1976b). Two techniques, "fostering" 
and "hacking" were used. Fostering is the addition of captive 
raised young to nests attended by wild parents, and hacking is 
the release of young birds from an artificial nest site without 
parents (Price 1980, Sherrod et al. 1982). Over the vast area 
where peregrines were absent, hacking was the only choice. 
In 1976, provincial wildlife agencies and the Canadian 
Wildlife Service embarked on an experimental program to release 
young peregrines in southern Canada. Releases have occurred at 
about 15 sites each year and have typically involved fewer than 
10 birds per site. The sites have been widely separated geo¬ 
graphically, occurring from Alberta to the Bay of Fundy. Hull 
was one of the sites initially chosen (Price 1980), and releases 
have occurred there every year from 1976 to 1986; 63 birds have 
been released to date (Table I). Approximately 750 young fal¬ 
cons have been released in Canada to date. 
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