Up until the 1940s, the breeding population peregrine falcons had changed little since mid-1500s to early 1600s. But in the 1950s and 1960s, a dramatic drop in the number of peregrine falcons was observed in Europe and North America. By the 1960s, peregrines were nearly extinct in the United States. By 1970 in Canada, there was only one known pair nesting in Canada east of the Rocky Mountains and south of the Northwest Territories.
This dramatic population decline at first puzzled ornithologists. Human activities, such as nest-robbing, trapping or shooting, were ruled out as the primary cause, since the peregrines had been subjected to these kinds of activities for hundreds of years. Further research showed that the timing and geography of the decline in peregrine populations corresponded closely with the intensive use of pesticides, such as DDT, after the Second World War.
High levels of pesticide residue (what is left after the chemicals break down in the environment or in an animal's body) have been found in adult peregrines, their eggs and in young birds found dead in the nest. Pesticides are sprayed on grain and insects which are eaten by birds which in turn are preyed upon by the peregrines. With each step up the food chain, the concentration of pesticide residue increases exponentially. Peregrines are relatively long-lived, have few natural enemies and are at the top of their food chain. As a result they are exposed to more pesticide contamination that most other predators. Though few peregrines are directly killed by pesticide residues, the high levels found in these birds result in abnormal breeding behaviour, thin eggshells that can be easily broken and dead embryos in the eggs themselves. As a result, contaminated breeding peregrines are less able to hatch young that survive. Similar population declines have been observed in other avian predators, particularly the osprey and the bald eagle.
In the early 1970s, Canada and the United States banned the use of DDT, however, it is still in use in several countries where peregrines winter. Moreover, songbirds wintering in Central and South America come north in the spring with these toxic chemical residues in their body tissues, which are then passed on to the peregrines when these birds are taken as prey. Even if the DDT problem was completely addressed, there may be other chemicals that prove to be injurious to the birds. Thus, for the peregrine falcon, being on top of a food chain has its price. For the human race, the peregrine, like the proverbial canary in the coal mine, is a barometer of environmental health.
An international conservation program began in the 1970s in Canada and in the U.S. in an attempt to bring back the peregrine falcon. In 1981, Manitoba Conservation's Wildlife and Ecosystem Protection Branch began Manitoba's peregrine reintroduction program with the release of four captive-bred falcons in Winnipeg.
In 1989, the Delta Winnipeg Hotel (now the Radisson Hotel Winnipeg Downtown) expressed an interested in helping support the program when the hotel became home to Manitoba’s first confirmed wild nesting peregrine falcons in more than 50 years. In 1993, two more wild nests were established, one in Brandon and the third in south Winnipeg.
Since 1981, the Project has been responsible for reintroducing over 250 young peregrines into the wild from locations in Winnipeg, Brandon, Portage la Prairie and Gimli.
Manitoba's peregrine falcons are legally protected as a species-at-risk at three levels - Manitoba's Endangered Species Act, the federal Species At Risk Act (SARA) and internationally by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).
In Canada and the United States it is illegal to kill or disturb peregrine falcons or their nesting areas.
If you would like more information on the Project or Manitoba’s Peregrine Falcons, please check out the Peregrine Falcon Recovery Project website.