Post by muskyhusky on Oct 19, 2008 0:51:22 GMT -6
Gray Wolves
by: L. David Mech National Biological Service Daniel H. Pletscher University of Montana Clifford J. Martinka National Biological Service
The gray wolf (Canis lupus) originally occupied all habitats in North America north of about 20° north latitude (in Mexico), except for the southeastern United States, where the red wolf (C. rufus) lived. By 1960 the wolf was exterminated by federal and state governments from all of the United States except Alaska and northern Minnesota. Until recently, 24 subspecies of the gray wolf were recognized for North America, including 8 in the contiguous 48 states. After the gray wolf was listed as an endangered species in 1967, recovery plans were developed for the eastern timber wolf (C.l. lycaon), the northern Rocky Mountain wolf (C.l. irremotus), and the Mexican wolf (C.l. baileyi). The other subspecies in the contiguous United States were considered extinct.
The Eastern Timber Wolf Recovery Plan set as criteria for recovery the following conditions: a viable wolf population in Minnesota consisting of at least 200 animals, and either a population of at least 100 wolves in the United States within 160 km (100 mi) of the Minnesota population, or a population of at least 200 wolves if farther than 160 km (100 mi) from the Minnesota population. The Northern Rocky Mountain Wolf Recovery Plan defined recovery as when at least 10 breeding pairs of wolves inhabit each of three specified areas in the northern Rockies for 3 successive years. The Mexican Wolf Recovery Plan called for a self-sustaining population of at least 100 Mexican wolves in a 12,800-km2 (4,941-mi2) range.
A recent revision of wolf subspecies in North America , however, reduced the number of subspecies originally occupying the contiguous 48 states from eight to four. It classified the wolf currently inhabiting northern Montana as being C.l. occidentalis, primarily a Canadian and Alaskan wolf. It considered C.l. nubilus to be the wolf remaining in most of the range of the former northern Rocky Mountain wolf and the present range of the eastern timber wolf; this leaves the eastern timber wolf extinct in its former U.S. range, surviving now only in southeastern Canada. The new classification may have implications for the recovery criteria propounded by the Eastern Timber Wolf and Northern Rocky Mountain Wolf recovery plans. The reclassification did not change the status of the Mexican wolf.
This article is based on a review of the literature and recent personal communications. Most of the studies cited depended primarily on the use of aerial radio-tracking and observation.
After wolves were protected in 1974 by the Endangered Species Act of 1973, their numbers and distribution in Minnesota increased, and individuals began recolonizing Wisconsin . The population increased in Wisconsin and began recolonizing Michigan . The Minnesota population increased at about 3% per year ; its distribution continues to increase. The best estimate of its current size is 1,740-2,030 wolves. Wisconsin and mainland Michigan each supported an estimated 50+ wolves in early 1994 (A.P. Wydeven, Wisconsin Department of Natural Resources, personal communication; J. Hammill, Michigan Department of Natural Resources, personal communication), and Isle Royale National Park about 14 wolves.
As wolves increased in Minnesota, they also began dispersing westward into North and South Dakota . The only records from these states involve 10 wolves killed from 1981 through 1992, but the possibility remains that small populations may occur in some of the more remote areas. Sufficient prey certainly exist there, so if dispersing wolves from Minnesota and Manitoba are not killed by humans, they should be able to breed and start populations.
Wolves were virtually absent in the western United States (other than an occasional animal that disperses from Canada) from the mid-1930's through 1980 . The nearest breeding population through this period was probably in Banff National Park, Alberta. Wolves were completely protected in extreme southeastern British Columbia in the 1960's. This led to recolonization of the area and adjacent northwestern Montana, and in 1986 a den was documented in Glacier National Park, Montana. This population, which straddles the Canadian border, has since grown to four packs and about 45 wolves.
Three breeding packs have been reported elsewhere in western Montana , all probably founded by animals that dispersed from Glacier National Park. Additionally, an animal that dispersed from Glacier is in northeastern Idaho, and a wolf shot in 1992 just south of Yellowstone National Park was genetically related to Glacier wolves (Fritts et al. 1994). Animals that have dispersed, primarily from the Glacier area, have begun back-filling the area between Glacier National Park and Jasper National Park, Alberta . This connection to larger wolf populations in Canada will enhance the viability of the U.S. population.
[Gray wolf (Canis lupus). Courtesy L.D. Mech, NBS]
Although occasional wolves have been sighted in Wyoming and Washington and numerous sightings have been reported from central Idaho, no reproduction has been documented in these states, with the possible exception of litters in Washington in 1990 (S.H. Fritts, U.S. Fish and Wildlife Service, personal communication). An environmental impact statement on the reintroduction of wolves to Yellowstone and central Idaho was completed in early 1994.
Factors Impeding Wolf Recovery
In small populations, the death of any individual can seriously impede recovery, meaning that factors that may not affect larger populations may hinder recovery of smaller ones. Such factors hindering the recovery of wolves include illegal and accidental killing of wolves by humans, canine parvovirus sarcoptic mange (A.P. Wydeven et al., Wisconsin Department of Natural Resources, personal communication), possibly Lyme disease , and heartworm . Of these, only killing by humans is subject to human control.
Future OutlookAll wolf populations in the contiguous 48 states are increasing. Minnesota wolves occupy all suitable areas there and even have been colonizing agricultural regions where the Eastern Timber Wolf Recovery Team felt they should not be (U.S. Fish and Wildlife Service 1992). Thus, in 1993, the Department of Agriculture's Animal Damage Control Program destroyed a record 139 wolves for livestock depredation control (Paul 1994). As wolf populations continue to grow in other newly colonized areas, there may be an increasing need for control of those wolves preying on livestock .Because the public has so strongly supported wolf recovery and reintroduction, it may be difficult for many to understand the need for control. Thus, strong efforts at public education will be required.
by: L. David Mech National Biological Service Daniel H. Pletscher University of Montana Clifford J. Martinka National Biological Service
The gray wolf (Canis lupus) originally occupied all habitats in North America north of about 20° north latitude (in Mexico), except for the southeastern United States, where the red wolf (C. rufus) lived. By 1960 the wolf was exterminated by federal and state governments from all of the United States except Alaska and northern Minnesota. Until recently, 24 subspecies of the gray wolf were recognized for North America, including 8 in the contiguous 48 states. After the gray wolf was listed as an endangered species in 1967, recovery plans were developed for the eastern timber wolf (C.l. lycaon), the northern Rocky Mountain wolf (C.l. irremotus), and the Mexican wolf (C.l. baileyi). The other subspecies in the contiguous United States were considered extinct.
The Eastern Timber Wolf Recovery Plan set as criteria for recovery the following conditions: a viable wolf population in Minnesota consisting of at least 200 animals, and either a population of at least 100 wolves in the United States within 160 km (100 mi) of the Minnesota population, or a population of at least 200 wolves if farther than 160 km (100 mi) from the Minnesota population. The Northern Rocky Mountain Wolf Recovery Plan defined recovery as when at least 10 breeding pairs of wolves inhabit each of three specified areas in the northern Rockies for 3 successive years. The Mexican Wolf Recovery Plan called for a self-sustaining population of at least 100 Mexican wolves in a 12,800-km2 (4,941-mi2) range.
A recent revision of wolf subspecies in North America , however, reduced the number of subspecies originally occupying the contiguous 48 states from eight to four. It classified the wolf currently inhabiting northern Montana as being C.l. occidentalis, primarily a Canadian and Alaskan wolf. It considered C.l. nubilus to be the wolf remaining in most of the range of the former northern Rocky Mountain wolf and the present range of the eastern timber wolf; this leaves the eastern timber wolf extinct in its former U.S. range, surviving now only in southeastern Canada. The new classification may have implications for the recovery criteria propounded by the Eastern Timber Wolf and Northern Rocky Mountain Wolf recovery plans. The reclassification did not change the status of the Mexican wolf.
This article is based on a review of the literature and recent personal communications. Most of the studies cited depended primarily on the use of aerial radio-tracking and observation.
Population Status by Region
Lake Superior Region
Lake Superior Region
After wolves were protected in 1974 by the Endangered Species Act of 1973, their numbers and distribution in Minnesota increased, and individuals began recolonizing Wisconsin . The population increased in Wisconsin and began recolonizing Michigan . The Minnesota population increased at about 3% per year ; its distribution continues to increase. The best estimate of its current size is 1,740-2,030 wolves. Wisconsin and mainland Michigan each supported an estimated 50+ wolves in early 1994 (A.P. Wydeven, Wisconsin Department of Natural Resources, personal communication; J. Hammill, Michigan Department of Natural Resources, personal communication), and Isle Royale National Park about 14 wolves.
As wolves increased in Minnesota, they also began dispersing westward into North and South Dakota . The only records from these states involve 10 wolves killed from 1981 through 1992, but the possibility remains that small populations may occur in some of the more remote areas. Sufficient prey certainly exist there, so if dispersing wolves from Minnesota and Manitoba are not killed by humans, they should be able to breed and start populations.
Western United States
Wolves were virtually absent in the western United States (other than an occasional animal that disperses from Canada) from the mid-1930's through 1980 . The nearest breeding population through this period was probably in Banff National Park, Alberta. Wolves were completely protected in extreme southeastern British Columbia in the 1960's. This led to recolonization of the area and adjacent northwestern Montana, and in 1986 a den was documented in Glacier National Park, Montana. This population, which straddles the Canadian border, has since grown to four packs and about 45 wolves.
Three breeding packs have been reported elsewhere in western Montana , all probably founded by animals that dispersed from Glacier National Park. Additionally, an animal that dispersed from Glacier is in northeastern Idaho, and a wolf shot in 1992 just south of Yellowstone National Park was genetically related to Glacier wolves (Fritts et al. 1994). Animals that have dispersed, primarily from the Glacier area, have begun back-filling the area between Glacier National Park and Jasper National Park, Alberta . This connection to larger wolf populations in Canada will enhance the viability of the U.S. population.
[Gray wolf (Canis lupus). Courtesy L.D. Mech, NBS]
Although occasional wolves have been sighted in Wyoming and Washington and numerous sightings have been reported from central Idaho, no reproduction has been documented in these states, with the possible exception of litters in Washington in 1990 (S.H. Fritts, U.S. Fish and Wildlife Service, personal communication). An environmental impact statement on the reintroduction of wolves to Yellowstone and central Idaho was completed in early 1994.
Factors Impeding Wolf Recovery
In small populations, the death of any individual can seriously impede recovery, meaning that factors that may not affect larger populations may hinder recovery of smaller ones. Such factors hindering the recovery of wolves include illegal and accidental killing of wolves by humans, canine parvovirus sarcoptic mange (A.P. Wydeven et al., Wisconsin Department of Natural Resources, personal communication), possibly Lyme disease , and heartworm . Of these, only killing by humans is subject to human control.
Future OutlookAll wolf populations in the contiguous 48 states are increasing. Minnesota wolves occupy all suitable areas there and even have been colonizing agricultural regions where the Eastern Timber Wolf Recovery Team felt they should not be (U.S. Fish and Wildlife Service 1992). Thus, in 1993, the Department of Agriculture's Animal Damage Control Program destroyed a record 139 wolves for livestock depredation control (Paul 1994). As wolf populations continue to grow in other newly colonized areas, there may be an increasing need for control of those wolves preying on livestock .Because the public has so strongly supported wolf recovery and reintroduction, it may be difficult for many to understand the need for control. Thus, strong efforts at public education will be required.