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After the second world war the use of pesticides, in particular DDT, increased dramatically. This chemical polluted the food chain through the sixties untilits use was banned internationally.

With few enemies and a long life span peregrines were at the top of the food chain. The concentration of the pesticides was therefore far higher in their syatems than in other birds. The contanination seriously damaged their ability to reproduce with success and so the population dwindled until it was nearly extinct.

The following is from Hinterlands who's who

The Committee on the Status of Endangered Wildlife in Canada designated the anatum subspecies as "endangered" in 1978. Recovery efforts that included captive breeding and reintroduction improved the subspecies' status, and in 2000, the designation was changed to "threatened." Similarly, the tundrius subspecies' "threatened" designation, assigned in 1978, was changed to "special concern" in 1992. The pealei subspecies has been designated a species of "special concern." The three subspecies are listed under the federal Species at Risk Act.

Since 1974, more than 1 650 Peregrines have been bred in captivity at the Canadian Wildlife Service breeding facility at Wainwright, Alberta, at university-based facilities in Saskatchewan and Quebec, and at a private facility in Alberta. Staff from wildlife agencies and non-profit organizations have released the captive-raised birds from natural cliffs and tall buildings at over 60 sites from southern Alberta to the Bay of Fundy on Canada's east coast. In 2005, there were more than 200 pairs of wild Peregrines breeding in southern Canada and more than 300 wild pairs in Yukon and the Mackenzie valley. Over 7 000 pairs of Peregrines are now thought to breed in North America, including Mexico

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14y ago

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