Diane Boyd, Edward Bangs, Joseph Fontaine, Thomas Meier,
U.S. Fish and Wildlife Service, 100 North Park Street Suite
320, Helena, MT 59601, USA; Daniel Pletscher, Wildlife Biology
Program, School of Forestry, University of Montana, Missoula,
MT 59812, USA; Douglas Smith, Yellowstone Center for Resources,
PO Box 621, Yellowstone National Park, WY 82190, USA; Curtis
Mack, Nez Perce Tribe, PO Box 365, Lapwai, ID 83540, USA; Mike
Jimenez, U.S. Fish and Wildlife Service, 190 North First Street,
Lander, WY 82520, USA
Gray wolves were eradicated from Montana in the 1930s but
recolonized these areas through natural dispersal from Canada
in the 1980s. From 1979 to 1997, 31 of 58 wolves tagged in and
near Glacier National Park (GNP), Montana, dispersed. By 1996,
8 wolf packs had colonized northwest Montana (MT) through dispersal.
Wolves left their natal home range quickly (median = 4 days,
mode = 1 day) after separating from the pack. Mean dispersal
distance was not different between males (113 km) and females
(78 km). GNP wolves tended to disperse in a northerly direction
to areas of higher wolf density. January-February and May-June
were peak months for dispersal. Mean dispersal age (M = 28.7
months; F = 38.4 months) was not correlated with maximum pack
size. Annual survival rate (mean + SE) for dispersers and biders
(philopatric wolves) did not differ (dispersers = 0.76 + 0.10;
biders = 0.77 + 0.14). Wolves killed by humans died closer to
roads (mean = 0.13 km) than wolves that died from other causes
(mean = 0.85 km).
Eighty percent (n = 30) of wolf mortalities were caused by
humans, with proportionately more dispersers (90%) than biders
(60%) dying from human causes. Dispersers produced more litters
than biders.
Additionally, wolves from Canada were reintroduced to central
Idaho (ID) and Yellowstone National Park (YNP) in 1995-96, aiding
recovery efforts demographically and genetically. The YNP and
ID populations increased more quickly than expected, and each
area now contains 2-3 times as many wolves as the colonizing
northwest Montana population. However, wolf recovery is not
assured and may be significantly impacted by stochastic environmental
events and political pressures. Reintroduced wolves dispersing
out of the ID and YNP core recovery areas have rarely survived
long enough to reproduce because they were killed by people.
Although the YNP and ID reintroductions have been lauded as
a restoration success, the connectivity of dispersers between
the reintroduced populations and the recolonizing population
appears to be tenuous at this time. The greatest conservation
challenge for western wolves will be expanding wolf recovery
outside of the refugia provided by large blocks of public land.
Managers can affect recovery positively by maintaining landscape
connectivity and minimizing wolf mortalities caused by humans.
Beyond 2000: