Northern Prairie Wildlife Research Center
Fur trapping records show that swift fox were a significant part of Canada's prairie landscape. Historically swift fox in Canada probably had a metapopulation structure with somewhat isolated subpopulations, some of which, due to a complex of circumstances periodically experienced significant population declines, if not local extinction. Some of the many interacting circumstances that would have, and to some extent still do, influence swift fox numbers are: winter severity, drought, the variety of diseases to which canids are susceptible, being killed by competing species such as coyotes, bobcats and raptors, and fluctuations in prey availability. When conditions are good, swift fox have enough reproduction capacity to generate a dispersing surplus which would have repopulated areas where numerical depression or extirpation occurred. Today Canada's reintroduced swift fox population exists in an environment dramatically different from the historic one. Whether or not a niche exists for swift fox in this altered environment can only be determined by monitoring the fate of reintroduced individuals and populations. Because of the complex set of factors that historically influenced swift fox populations the answer cannot be strictly predicted. Some of the critical parameters that controlled swift fox numbers in historic environments should influence the design of the reintroduction effort. Examples would be planning for dispersal and metapopulation structure, providing escape terrain through locally encouraging badger populations, and anticipating disease outbreaks and their consequences. There is little doubt that swift fox would do best in a prairie environment in which key elements were as similar as possible to historic ones. Additionally, this might include bison populations generating carrion, wolves to depress currently high coyote populations, and an abundance of ground nesting birds and insects. Given that many factors of the historic prairie environment will not be recreated, the swift fox reintroduction will remain an experiment in ecological restoration and a comment on the prairie as a natural system.