Conserving Borderline Species: A Partnership between the United States and Canada
Mammals
Black-footed Ferret (Mustela nigripes)
Status
Canada (COSEWIC): Extirpated
U.S. (USFWS): Endangered; Experimental populations (specific portions of Arizona, Colorado, Montana, South Dakota, Utah, and Wyoming)
Photo U.S. Fish and Wildlife Service
Description
The black-footed ferret is North America's only native ferret species. It is about the size of a mink, reaching nearly 60 centimeters (2 feet) in total length and weighing up to 1.1 kilograms (2.5 pounds). It is buff colored with black legs and feet, a black-tipped tail, and a white face with a dark band across the eyes which forms a distinctive mask. It has short, rounded ears and large black eyes.
Ecology
Black-footed ferrets prey primarily on prairie dogs and use prairie dog burrows for shelter and raising young. In fact, the ferret's historical range closely coincides with that of three prairie dog species. Ferrets breed in the spring, April to May, with a gestation period of about 42 days. Each female produces a litter of three or four kits on average. They don't mate for life, and the male plays no role in rearing. Kits begin to disperse at about four to five months of age.
Causes of Decline
The black-footed ferret's known historical range once extended from the Canadian Prairie Provinces of Alberta and Saskatchewan to the southwestern United States, including twelve States: Arizona, Colorado, Kansas, Montana, Nebraska, New Mexico, North Dakota, Oklahoma, South Dakota, Texas, Utah, and Wyoming. Biologists can't be sure of the ferret's historical range abundance due to its nocturnal and secretive habits. In the last century, agricultural cultivation greatly reduced the ferret's prairie habitat. In addition, widespread prairie dog poisoning and sylvatic plague have drastically reduced prairie dog populations throughout North America, nearly exterminating the ferret. The absence of large, healthy prairie dog habitats remains the central threat to ferrets today.
Research and Recovery
Canadian and U.S. scientists have been cooperating in black-footed ferret recovery since the early 1990s. In the late 1970s, ferrets were thought to be extinct. But in 1981, researchers discovered a small population near Meeteetse, Wyoming. By 1985, the Meeteetse population began to crash from diseases. To salvage the species, scientists captured all ferrets between 1985 and 1987 and moved them to a captive-breeding center at the Wyoming Game and Fish Department's Sybille Research Facility (now known as the U.S. Fish and Wildlife Service's National Black-footed Ferret Conservation Center). By 1988, biologists had succeeded in breeding and rearing kits in captivity, and began to expand the captive population to other breeding facilities. In 1991, they began reintroducing ferrets into the wild in the Shirley Basin of Wyoming. However, because of sylvatic plague in prairie dog populations, release efforts were suspended in Wyoming in 1995. Reintroduction projects were initiated in Montana and South Dakota in 1994, in Arizona in 1996, in Colorado and Utah in 1999, and at a second site in north-central South Dakota in 2000.
To date, only one potential self-sustaining population of ferrets has been established in the wild. In the Conata Basin/Badlands area of South Dakota, more than 60 wild-born litters and 150 kits were documented during the summer of 2000. Moderate success has also been achieved at a reintroduction area on the U.L. Bend National Wildlife Refuge in Montana where 16 litters and 43 kits were observed during the summer of 2000. Although Canadian scientists wish to reintroduce the ferret to the wilds of Alberta and Saskatchewan, black-tailed prairie dog numbers are currently insufficient to support a ferret population. No wild ferrets are known to exist today outside of the reintroduction areas.
In 1992, the Metro Toronto Zoo launched a black-footed ferret captive-breeding program. Since then, the zoo has sent captive-bred ferrets to reintroduction programs in three States. Wildlife biologists and zoo staff from Canada and the United States are cooperating to develop and refine captive-rearing methods to increase overall black-footed ferret production. The Metro Toronto Zoo has conducted valuable research in areas of reproduction, animal behavior, and ferret nutrition. A ferret diet devised at the zoo has become the standard diet used at the U.S. Fish and Wildlife Service's National Black-footed Ferret Conservation Center. In addition to the National Black-footed Ferret Conservation Center and the Metro Toronto Zoo, four zoos in the United States currently house and breed black-footed ferrets. The captive population now numbers 400 animals in six separately maintained locations.
In September of 2000, the Metro Toronto Zoo hosted the annual Black-footed Ferret Species Survival Plan meeting, which involves Canadian and U.S. scientists working to re-establish the ferret. Experts in captive production of ferrets attended the meeting to help direct future management and recovery efforts for the species, and to select genetic pairings for future ferret breeding.
Swift Fox (Vulpes velox)
Status
Canada (COSEWIC): Endangered
U.S. (USFWS): Endangered (Canadian population of V. velox hebes)
Photo Lu Carbyn
Description
The swift fox is the smallest member of the North American wild dog family. Named for its quickness, a swift fox is only the size of a house cat but can keep pace with a jackrabbit at speeds of over 60 kilometers (37 miles) per hour. The swift fox is buffy-yellow, with fur that grows thicker toward the end of summer. It has a black tip on its bushy tail, and large, pointed ears, with characteristic black shading on its muzzle.
Ecology
Swift foxes are mainly nocturnal. During the day they usually remain in the vicinity of the den. They often live in pairs, although they may not mate for life. Breeding occurs during January and February, and the average spring litter consists of four or five pups. Swift foxes eat mostly mice, cottontail rabbits, and carrion, although they will also feed on other small mammals, birds, insects, reptiles, and amphibians. Swift foxes prefer open, sparsely vegetated short-grass and mixed-grass prairie, where they have a good view and can move about easily.
Causes of Decline
The swift fox once ranged from the Canadian Prairies to Texas, but suffered a severe decline beginning in the early 1900s. It disappeared from Canada, but remains in 9 of 10 States where it was historically found, most commonly in Colorado, Kansas, and Wyoming. A thorough review by the Northern Prairie Wildlife Research Center (North Dakota) of the swift fox's historical range and current distribution indicates it still occurs throughout approximately 40 percent of its historical range. Hunting, loss of habitat, accidental trapping and poisoning during predator control programs, and harsh winters and droughts all contributed to the disappearance of the swift fox from Canada. The conversion of native prairie grasslands to farmland has reduced the quantity and quality of available swift fox habitat. Current threats include ongoing cultivation and development on the prairie and competition from coyotes for food and living space.
Research and Recovery
Canadian and U.S. experts have cooperated closely in swift fox reintroduction efforts in Canada. Since 1973, a total of 151 wild foxes have been captured in Colorado, South Dakota, and Wyoming. Some of these foxes were sent to Canadian captive-breeding facilities, while many others were released directly into the Canadian wild. Since 1983, more than 800 captive-raised swift foxes were released in Alberta and Saskatchewan. Most of these foxes were from captive colonies raised in facilities at Cochrane, Alberta, and Moose Jaw, Saskatchewan. Despite severe winter weather and predation by bobcats, coyotes, and eagles, many foxes survived and have begun reproducing. The latest population estimate (1996) is of 289 swift foxes in the wild in Canada, the majority on the Alberta/Saskatchewan border, plus a small population in adjacent areas of Montana.
In 1998, at the request of the Blackfeet Tribe, Canada and the United States began a cooperative reintroduction program of swift foxes on the Blackfeet Reservation in Montana. The Blackfeet Tribe invited Alberta's Cochrane Ecological Institute to help conduct the project. The Institute agreed to provide swift fox offspring from its captive colony, and participated in release planning, permitting, and academic liaison and research. Two reintroductions took place, the first one in 1998 and a second one in 1999. Follow-up surveys indicated that the swift foxes released in 1998 were surviving and reproducing in the wild. Since 1998, Canadian scientists have cooperated with Montana to define the size and extent of the swift fox population that has spread from Canadian releases into the United States.
Woodland Caribou (Rangifer tarandus caribou)
Status
Canada (COSEWIC): Endangered (Atlantic-Gaspésie population); Threatened (Boreal and Southern Mountain populations)
U.S. (USFWS): Endangered (Selkirk population)
Photo André Dumont
Description
The woodland caribou is the largest caribou subspecies in North America. Its body is covered in long, thick hairs that are mostly brown in summer and nearly gray in winter. It has large feet with crescent-shaped, cloven hooves for walking in snow or swamps. A creamy white color is noticeable on the caribou's neck, mane, underbelly, and the underside of the tail. It also has a white shoulder stripe, and white patches just above each hoof. Woodland caribou grow antlers each year, and shed them in winter.
Ecology
In Canada, woodland caribou herds generally remain in mature forest areas, often near marshes, bogs, lakes, and rivers. In mountainous environments, caribou inhabit subalpine and alpine habitats. In the United States, the Selkirk population inhabits high elevation ridges and mountainsides, descending in early winter to mature and old growth cedar/hemlock and spruce/fir stands which provide protection from the snow. In winter, caribou eat primarily ground and tree lichens. They also eat shrubs, grasses, and willows. Females usually begin reproducing at three years of age. The breeding season occurs in early- to mid-October. Pregnant females migrate to remote, secluded sites at high elevations or marshy areas to give birth. Calves, usually one per female, are born in late spring or early summer.
Causes of Decline
Woodland caribou declined in the 1800s and early 1900s, largely from over-hunting and predation. Today, most caribou herds are declining or remain stable at low numbers. Overall numbers have declined to less than 200,000 in Canada and the United States, including just under 50,000 in the boreal population that stretches from Alaska and British Columbia to Labrador. A few thousand occur in southern Alberta and British Columbia. A remnant population of just 35 caribou inhabits the Selkirk Mountains of southeastern British Columbia, northern Idaho, and northeastern Washington. Current threats include habitat degradation and fragmentation, predation by wolves, mountain lions, and bears, as well as human disturbance. In many parts of caribou range, habitat has been depleted, altered, or fragmented by logging practices, which reduce the amount of ground and tree lichens. Other threats include agriculture, oil and gas exploration, and mining. Forest fires have also contributed to habitat alteration.
Research and Recovery
Since the late 1980s, the provincial government of British Columbia has cooperated with several U.S. agencies to bolster a remnant herd of woodland caribou in the southern Selkirk Mountains. The Province provided caribou for two separate augmentation projects conducted by the U.S. Fish and Wildlife Service, the U.S. Forest Service, and the States of Idaho and Washington. One occurred between 1987 and 1990, and the other between 1996 and 1998, totaling 103 caribou. Provincial officials participate in the U.S. Fish and Wildlife Service's woodland caribou recovery team and the International Mountain Caribou Technical Committee.
As part of the Selkirk Mountains project, wildlife biologists radio-collared all translocated animals and have monitored them since their release. Biologists also conducted annual aerial winter surveys to monitor the entire Selkirk Mountain population. The transplanted caribou experienced relatively high death rates. Since 1997, half of the caribou that existed in the herd prior to the translocation have also died. Although the cause of death is unknown in many cases, predation was a significant factor in known deaths. The population currently consists of 35 caribou, as compared to 25 to 30 in the mid-1980s. Scientists believe that this cooperative venture has temporarily prevented the Selkirk Mountain caribou population from becoming extirpated.
Grizzly Bear (Ursus arctos)
Status
Canada (COSEWIC): Extirpated (Prairie population); Special Concern
U.S. (USFWS): Threatened (Lower 48 States); Experimental populations (portions of Idaho and Montana)
Photo Parks Canada/Wayne Lynch
Description
The grizzly bear is a solitary, smaller form of the brown bear. Larger than a black bear, the grizzly bear has a characteristic hump on its shoulders, a dished-in nose, and long fur that ranges in color from a creamy yellow to black, usually with some white-tipped hairs around the face and on the shoulders, creating a grizzled appearance. The thick winter underfur is rubbed off in the late spring.
Ecology
The grizzly bear has a large home range and many specific habitat requirements. It needs adequate spring, summer, and fall foods, appropriate sites to den, suitable protective cover, and isolation from human disturbance. Grizzly bears are omnivorous and feed on berries, salmon, plants, insects, and mammals ranging in size from ground squirrels to moose calves. They might even feed on a beached whale or other carrion. Bears are most active in the evening and early morning hours. Breeding occurs in June and July. Cubs, usually two per litter, are born in the den in January and February. In late autumn, grizzly bears excavate a hole or seek the shelter of a natural cavity for their winter dens, hibernating until early spring.
Causes of Decline
The grizzly bear's range once extended across the western half of North America from Alaska to Mexico. Its range still spans the Provinces of Alberta and British Columbia and the States of Idaho, Montana, Washington, and Wyoming. The grizzly bear also inhabits Alaska and Canada's three northern Territories: the Northwest Territories, Nunavut, and the Yukon. The total Canadian population is estimated at about 22,000 bears. Humans are responsible for the grizzly bear's historical decline, through unregulated hunting and habitat degradation. Today, bear hunting is regulated in Canada and prohibited in the Lower 48 States. Nevertheless, the grizzly continues to face the risk of habitat disturbance, including habitat loss, habitat fragmentation, increased human disturbance, and high road density.
Research and Recovery
Since the early 1980s, U.S. and Canadian wildlife experts have cooperated to coordinate grizzly bear recovery in Idaho, Montana, Washington, Wyoming, and southern portions of Alberta and British Columbia. To follow the bears' movements and other activities, scientists trap grizzly bears on both sides of the border, fit them with radio-collars, then monitor the radio signals by aircraft. Scientists have developed a computer model to predict possible grizzly bear habitat linkages. Experts in both countries are using the model's results to potentially maintain and re-establish connections between grizzly bear populations and habitats.
In the early 1990s, scientists augmented a small U.S. population by translocating four young female grizzly bears from British Columbia into the Cabinet Mountains of Montana. In 1995, the provincial government in British Columbia launched a Grizzly Bear Conservation Strategy which aims to maintain grizzly bear abundance throughout the Province. Under the strategy, the government created an independent committee consisting of Canadian and U.S. scientists to advise the B.C. Minister of the Environment on grizzly bear conservation. In another joint effort, scientists from both countries participate on the Rocky Mountain Grizzly Bear Planning Committee, which coordinates data collection and management actions on grizzly bears in the Rocky Mountains from the north side of Jasper National Park in Alberta south to northwestern Montana.
In 1999, the British Columbia government launched recovery planning for specified habitat areas with threatened grizzly bear populations. As part of this initiative, scientists from Canada and the United States are drafting a recovery plan for the North Cascades grizzly population in British Columbia along the U.S. border, where few grizzly bears remain. The plan will address habitat protection, reduction of bear-human conflicts, improvement of public information and education, and research and monitoring of the North Cascades grizzly bears. Meanwhile, in the United States, biologists are completing a plan to re-establish a grizzly bear population in the largest block of wilderness in the U.S. Rocky Mountains. The reintroduced population will consist of a combination of bears from each country.
