The swift fox is again roaming the native grasslands of southwest Saskatchewan, but efforts continue to improve the survival chances of this threatened species.
Dr. Shelley Pruss, a Parks Canada species at risk ecologist, spoke about the success of the swift fox reintroduction program during a presentation at the Semiarid Prairie Agricultural Research Centre in Swift Current Jan. 16.
Her talk was part of the Saskatchewan Prairie Conservation Action Plan (SK PCAP) Native Prairie Speaker Series, which aims to highlight conservation and management efforts within the prairie ecozone.
She started her presentation by highlighting the number of species at risk in Canada. For 15 species it is already too late, as they are extinct.
Twenty-three species are extirpated, which means they no longer exist in the wild in Canada.
“Every time I give this talk I have to change those numbers and I give talks about species at risk fairly often,” she said. “The numbers aren’t going down.”
Another 287 species are endangered and are facing imminent disappearance from Canada, 161 are threatened and need dedicated action to reverse their decline while 179 are of special concern, meaning they are sensitive to human activities and natural events.
The swift fox is native to the North American prairie. It is about 30 centimetres high at the shoulder and weighs 2.2 to 2.4 kilograms. Their numbers have been in decline since the 1800s as a result of trapping and hunting, poisoning and loss of habitat.
Pruss said Hudson’s Bay Company records show a large scale harvesting of swift fox pelts, with 117,000 pelts sold between 1853 and 1877. The record year was 1858, when 10,000 pelts were recorded.
“But by 1920, the average harvest was just over 500 pelts per year and then by 1925 the harvest was so low that they stopped keeping records for swift fox,” she noted.
Swift fox mortality also increased as an indirect result of poisoning campaigns aimed at wolves and coyotes. In the early 1870s an observer near Fort Macleod, Alta., counted over 200 dead wolves within one mile of a poisoned bison carcass.
Increased agricultural and grazing activities on the native prairie reduced their natural habitat.
As a result, the last recorded sighting of a Swift Fox took place in 1938 near the southeast Alberta community of Manyberries.
Efforts to reintroduce the swift fox to the Canadian prairie started in 1973, when Miles and Beryl Smeeton of Cochrane, Alta., began a captive breeding program.
Various agencies became involved over the years along with local landowners, communities and volunteers. In 1983, after an absence of almost 50 years, the first swift fox releases began.
“So 30 years later there’s a lot of optimism that this reintroduction has been a success,” Pruss said.
During the 1990s Pruss spent months on the Saskatchewan-Alberta border to study swift fox behaviour. The focus of her research was their requirements for dens and how they raise their kits, because suitable dens is an important factor in their recovery.
“They often modify badger holes and use them as natal dens and places to escape,” she said. “My results indicated that they preferentially choose dens that are located on the tops of hills with gradual slopes with longer new grass that’s closer to roads and further from water.”
Avoiding coyotes is important when swift foxes select den sites. Predation is a key factor that limits the expansion of swift foxes on the prairie, but coyotes are not their only concern. Red foxes can be an even bigger threat.
“Red foxes eat the same food and they take over their dens and so they out compete the swift fox,” Pruss explained. “We need the neighbourhood coyote to keep the red fox numbers in check, but not so many coyotes as to hit the swift fox too hard.”
A 2005/06 survey indicated there was a three-fold increase in swift fox numbers since the 1996/97 survey. From 1996/97 to 2005/06 the Alberta-Saskatchewan border population increased from 192 to 513 individuals, the Grasslands National Park region had an increase from 87 to 134 individuals while the Montana area supports around 515 foxes for a total of 1,162 swift foxes in the Canada-Montana area.
Before 2000, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) considered the swift fox to be extirpated. In 2000, they were downlisted to endangered species status and in 2009, they became a threatened species. Despite an increase in numbers, the swift fox is still vulnerable.
Pruss said the ongoing recovery strategy will now focus on their habitat needs. For her, an important lesson from working with species at risk has been the need to have community support and participation, as it requires a concerted effort by many groups and people to save a species.
“But ultimately, the other lesson is that we all share the challenge of protecting Canada’s wildlife species at risk,” she said.
The next SK PCAP Native Prairie Speaker Series presentation in Swift Current will take place Feb. 6 at 12:10 p.m. in the Ministry of Agriculture boardroom. Rebecca Magnus will present the results from the 2011 International Piping Plover Census.