Northern Rocky Mountain wolves, a subspecies of the gray wolf (
Canis lupus),
were native to Yellowstone when the park was established in 1872.
Predator control was practiced here in the late 1800s and early 1900s.
Between 1914 and 1926, at least 136 wolves were killed in the park; by
the 1940s, wolf packs were rarely reported. By the 1970s, scientists
found no evidence of a wolf population in Yellowstone; wolves persisted
in the lower 48 states only in northern Minnesota and on Isle Royale in
Michigan. An occasional wolf likely wandered into the Yellowstone area;
however, no verifiable evidence of a breeding pair of wolves existed
through the mid 1990s. In the early 1980s, wolves began to reestablish
themselves near Glacier National Park in northern Montana; an estimated
75 wolves inhabited Montana in 1996. At the same time, wolf reports were
increasing in central and north-central Idaho, and wolves were
occasionally reported in the state of Washington. The wolf is listed as
"endangered" throughout its historic range in the lower 48 states except
in Minnesota, where it is "threatened."
National Park Service (NPS) policy calls for restoring native species
when: a) sufficient habitat exists to support a self-perpetuating
population, b) management can prevent serious threats to outside
interests, c) the restored subspecies most nearly resembles the
extirpated subspecies, and d) extirpation resulted from human
activities.
The U.S. Fish & Wildlife Service 1987 Northern Rocky Mountain Wolf Recovery Plan
proposed reintroduction of an "experimental population" of wolves into
Yellowstone. In a report to Congress, scientists from the University of
Wyoming predicted reductions of elk (15%-25%), bison (5%-15%), moose,
and mule deer could result from wolf restoration in Yellowstone. A
separate panel of 15 experts predicted decreases in moose (10%-15%) and
mule deer (20%-30%). Minor effects were predicted for grizzly bears and
mountain lions. Coyotes probably would decline and red foxes probably
would increase.
In October 1991, Congress provided funds to the U.S Fish &
Wildlife Service (USFWS) to prepare, in consultation with the NPS and
the U.S. Forest Service, an Environmental Impact Statement (EIS) on
restoring wolves to Yellowstone and central Idaho. After several years
and a near-record number of public comments, the Secretary of Interior
signed the Record of Decision on the Final Environmental Impact
Statement (FEIS) for reintroduction of gray wolves to both areas. Staff
from Yellowstone, the USFWS, and participating states prepared to
implement wolf restoration. The USFWS prepared special regulations
outlining how wolves would be managed as a nonessential experimental
population under section 10(j) of the Endangered Species Act. These
regulations took effect in November 1994. As outlined in the Record of
Decision, the states and tribes would implement and lead wolf management
outside the boundaries of national parks and wildlife refuges, within
federal guidelines. The states of Idaho, Wyoming, and Montana have begun
preparation of wolf management plans.
Park staff assisted with planning for a soft release of wolves
in Yellowstone. This technique has been used to restore red wolves in
the southeastern United States and swift fox in the Great Plains and
involves holding animals temporarily in areas of suitable habitat.
Penning of the animals is intended to discourage immediate long-distance
dispersal. In contrast, a hard release allows animals to
disperse immediately wherever they choose, and has been used in Idaho
where there is limited access to the central Idaho wilderness.
In the autumn of 1995 at three sites in the Lamar Valley, park staff
completed site planning, and archaeological and sensitive plant surveys.
Approximately 1 acre was enclosed at each site with 9-gauge chain link
fence in 10' x 10' panels. These enclosures could be dismantled and
reconstructed at other sites if necessary. The fences had a 2' overhang
and a 4' skirt at the bottom to discourage climbing over or digging
under the enclosure. Each pen had a small holding area attached, to
allow a wolf to be separated from the group for medical treatment.
Inside each pen were several plywood security boxes to provide shelter.
For the 1996 release, one pen was relocated to Blacktail Plateau and
another was constructed in the Firehole Valley in central Yellowstone.
Subsequently pens have been relocated from Lamar to other areas in the
park interior to facilitate releases into other geographic areas or the
park or special circumstances that require the temporary penning of
wolves.
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