Technical ReportPDF Available

Making Room for Wolf Recovery: The Case for Maintaining Endangered Species Act Protections for America's Wolves

Authors:

Abstract and Figures

The report analyzes 27 gray wolf habitat modeling studies and identifies 359,000 square miles of additional habitat for gray wolves in 19 of the lower 48 states that could significantly boost the nation's 40-year wolf recovery efforts. The gray wolf population could be doubled to around 10,000 by expanding recovery into areas researchers have identified as excellent habitat that is yet unoccupied by wolves in the Northeast, West Coast, Western Great Lakes, southern Rocky Mountains, the Grand Canyon, Southwest and Texas. According to the studies, these areas are capable of supporting a minimum of 5,000 wolves, which would nearly double the existing wolf population. The report documents 56 instances over 30 years where wolves have dispersed from existing core recovery areas to states where they have yet to reestablish. These events, which frequently have ended in the dispersing wolves being shot, highlight the need for continued federal protections and recovery planning to increase the odds for dispersing wolves to survive and recolonize former terrain. Recovering wolves to these additional areas is necessary to ensure the long-term survival of gray wolves in the lower 48 states and enrich the diversity of U.S. ecosystems that have lacked the gray wolf as a top predator for decades. At last count the three existing wolf populations combined include only roughly 5,400 wolves, which is below what scientists have identified as the minimum viable population size necessary to avoid extinction. In wolf recovery areas where federal protections have been removed, under state management aggressive wolf hunting and trapping seasons have been set, resulting in declines in wolf populations. With gray wolf populations isolated from one another and experiencing declines, doubling the population by facilitating wolf recovery in additional areas is needed to secure the future of gray wolves in the U.S. Studies following reintroduction of wolves to Yellowstone National Park have documented that wolves as top predators play pivotal roles in shaping the structure and function of ecosystems, benefitting a wide range of species, including beavers, songbirds, grizzly bears, foxes, bison, pronghorn and more. Gray wolves are also a substantial draw for people from around the world. Millions of people have traveled to Yellowstone from around the world to see the gray wolves reintroduced in 1995 and 1996, and polls consistently show that a broad majority of the American public supports the recovery of gray wolves, including to new areas where they don't currently occur. Instead of stripping gray wolves of federal endangered species act protections in most of the lower 48, as is currently proposed by the Obama administration, a national recovery plan should be developed to restore wolves to suitable habitat the species once called home.
Content may be subject to copyright.
Making Room for Wolf Recovery:
e Case for Maintaining Endangered Species Act Protections for Americas Wolves
S
a
v
i
n
g
W
i
l
d
l
i
f
e
f
o
r
2
5
Y
e
a
r
s
Amaroq Weiss, Noah Greenwald, Curt Bradley
November 2014
southern Rocky Mountains, Grand Canyon, Cascade
Mountains in Washington, Oregon and California,
the Sierra Nevada and the Adirondacks are all places
that could support wolf populations. According to
the studies, these areas are capable of supporting a
minimum of 5,000 wolves, which would nearly double
the existing wolf population.
Recovering wolves to these additional areas is
necessary to ensure the long-term survival of gray
wolves in the lower 48 states and enrich the diversity
of U.S. ecosystems that have lacked the gray wolf
as a top predator for decades. At last count the three
existing wolf populations combined include only
roughly 5,400 wolves, which is below what scientists
have identied as the minimum viable population
size necessary to avoid extinction. Considering that
populations are now declining and isolated at several
scales, doubling the population by facilitating wolf
recovery in additional areas is needed to secure the
future of gray wolves in the U.S.
Studies following reintroduction of wolves to
Yellowstone National Park have documented that
wolves as top predators play pivotal roles in shaping
the structure and function of ecosystems, benetting
a wide range of species, including beavers, songbirds,
grizzly bears, foxes, bison, pronghorn and more.
Gray wolves are also a substantial draw for people from
around the world. Millions of people have traveled to
Yellowstone from around the world to see the gray
wolves reintroduced in 1995 and 1996, and polls
consistently show that a broad majority of the American
public supports the recovery of gray wolves, including
to new areas where they don’t currently occur.
I. Executive Summary
In 2011 the U.S. Fish and Wildlife Service removed
Endangered Species Act protections for wolves in the
northern Rocky Mountains and western Great Lakes,
arguing that wolves were recovered in those regions
and the states could be trusted to manage them. But
all of the states with substantial wolf populations have
enacted aggressive hunting and trapping seasons that
are intended to drastically reduce wolf populations. To
date these hunts have resulted in the killing of more
than 2,800 wolves. The deaths of so many wolves
have contributed to declines in wolf populations of
9 percent in the northern Rockies and 25 percent in
Minnesota. Given increased efforts to kill wolves
in many states, these declines can be expected to
continue and likely increase.
Despite the nightmare that state management of wolves
has been, the Fish and Wildlife Service has proposed to
remove protections for gray wolves in the remainder of
the lower 48 states, excluding a small portion of Arizona
and New Mexico, where the Mexican gray wolf struggles
to survive. The agency argues that growth of populations
in the northern Rockies and Great Lakes is sufcient
to consider the species recovered and to remove
Endangered Species Act protections.
In this report, we make the case that the job of
recovering wolves is far from complete by:
Identifying and mapping suitable habitat not
currently occupied by wolves;
Documenting dispersals of wolves to this
habitat;
Detailing the limitations of current
management plans;
Highlighting the important roles wolves play in
ecosystems.
Gray wolves currently occupy less than 10 percent of
their historic range and a fraction of currently suitable
habitat. To identify and map unoccupied, suitable wolf
habitat in the United States, we used 27 studies that
model wolf habitat in different regions to create a single
map. Based on this analysis, there is up to 530,000
square miles of suitable wolf habitat in the United
States, only roughly 171,000 square miles of which is
occupied, demonstrating that wolves currently occupy
only about 30 percent of existing suitable habitat. The
1
Wenaha pack male courtesy ODFW
Cover photo by Chris Smith / Flickr
The agency is now proposing to remove protections
for wolves across the lower 48 excluding a portion
of the range of the Mexican gray wolf in Arizona and
New Mexico (FWS 2013). This proposal disregards
that there are only roughly 5,400 wolves in portions
of the Midwest (~3,700 wolves), northern Rockies
(~1,670) and Southwest (~80) (FWS 2013), and the
states are actively working to reduce populations.
Moreover, wolves occupy just a fraction of their
historic range, less than 10 percent, and only a small
portion of existing suitable habitat. Indeed, multiple
researchers have modeled extensive suitable habitat
for wolves in the Northeast, Pacic Northwest,
southern Rocky Mountains, California and elsewhere.
To describe the full extent of suitable habitat available
for further recovery of wolves, we reviewed literature
estimating existing wolf habitat, created composite
maps of all known wolf habitat in the lower 48,
quantied unoccupied habitat, and estimated the
minimum number of wolves that could occur in this
habitat. We also quantied and mapped wolf dispersal
events over the past 30 years. In the following
discussion, we present the results of these analyses,
further discuss the history of efforts to remove
protections for wolves, including discussion of the
current proposal, and provide a rationale for not
walking away from wolf recovery now.
III. Studies Estimating Wolf Habitat in the
United States
We reviewed 27 studies that modeled potential wolf
habitat in the lower 48 states and used the composite
results to estimate and map the full range of potential
unoccupied wolf habitat and the number of wolves that
could be supported in the lower 48 (Appendix A). The
studies modeled wolf habitat across the western United
States, the upper Midwest and the Northeast (Appendix
B). This likely encapsulates a majority of existing wolf
habitat in the United States excluding the range of the
red wolf in the Southeast. But there may be additional
habitat in North and South Dakota and other areas that
should be the subject of additional modeling.
Predictive modeling parameters used in the studies
consisted of road density (26 studies), human
population density (20 studies), prey density (20
studies) and land cover/use (16 studies). Some
studies used additional parameters including
II. Introduction
Gray wolves once occupied the majority of North
America, excluding perhaps only the driest deserts and
the southeastern United States, where the red wolf occurs
(FWS 2013). Scientists estimate that pre-European
settlement there may have been as many as 2 million
wolves in North America (Leonard et al., 2005). During
the late 19th century and early 20th century, state and
local bounties reduced wolf numbers. From 1915
through mid-century, the U.S. government exterminated
wolves from the United States and Mexico (Seton, 1929;
Young and Goldman, 1944). By 1967, when wolves
were protected under a precursor to the Endangered
Species Act, they had been reduced to fewer than 1,000
wolves in northeastern Minnesota (FWS 2009).
With protection, wolves began to see some recovery,
but only in portions of their former range where the
U.S. Fish and Wildlife Service (FWS) developed
recovery programs. Wolves were originally protected
as four subspecies -- the northern Rockies wolf,
eastern wolf, Mexican wolf and Texas wolf (FWS
1978). Recognizing that these subspecic designations
were potentially invalid, FWS consolidated protection
for gray wolves to the species level in 1978, including
the entire lower 48 states (Ibid.) The agency, however,
never developed a national strategy to recover wolves
in the lower 48 in line with expanded protection.
Instead it completed recovery plans that had already
been started in 1978 for three of the four purported
subspecies, excluding the Texas wolf.
With recovery programs in place, including
reintroduction of wolves in portions of the northern
Rocky Mountains, wolves began to grow in number
and expand their range in the northern Rockies and
western Great Lakes states. Mexican wolves were
also reintroduced to a portion of the Southwest, but
their numbers have grown slowly. In 2003 FWS began
moving to delist wolves in the northern Rockies and
western Great Lakes, and after multiple rounds of
litigation in which the agency was repeatedly found
not to have followed best science, were successful in
removing protections in both regions in 2011 (FWS
2011ab). Since delisting, all states in the northern
Rockies and western Great Lakes have instituted
aggressive hunting and trapping seasons intended to
drastically reduce wolf populations.
2
and the Sierra Nevada in California. In the northeastern
United States, thousands of square miles of terrain
spanning upstate New York and portions of Vermont,
New Hampshire and Maine were identied as capable of
supporting a wolf population. And some studies indicate
the lower peninsula of Michigan could support wolves.
According to our mapping, there are approximately
530,000 square miles of suitable wolf habitat in the
lower 48, of which roughly 171,000 square miles are
currently occupied, meaning wolves have recovered
to only roughly 30 percent of known suitable habitat.
Although not all studies estimated the number of wolves
that could be supported, those that did suggest that at
least another 5,000 wolves could populate the Northeast,
southern Rockies, West Coast and Southwest, nearly
doubling the existing population and creating a network
of interconnected populations bolstering genetic security.
IV. Wolves Are Dispersing Into Areas of
Suitable Habitat and Need Endangered
Species Act Protections to Survive
Not only is there extensive suitable habitat in other
land ownership (11 studies), livestock density (7
studies), slope or elevation (5 studies), climate or
snowfall (4 studies), surface water availability (4
studies), and prey accessibility or availability (3
studies). Two studies used soil depth or hydrology
(Appendix C).
Past modeling of wolf habitat has accurately predicted
wolf occupancy in both the northern Rockies and
Midwest, suggesting modeling can accurately convey
potential wolf habitat. We used 14 of the 27 studies to
create a composite map of wolf habitat for the lower
48 states (Figure 1). We did not use all of the studies
because in some cases they represented different
modeling iterations for the same areas by the same
authors, and in others there was insufcient spatial
information to allow mapping.
Reviewed studies identied extensive wolf habitat in
regions where wolves have not yet recovered. In the
western United States, this includes the central and
southern Rocky Mountains in both Colorado and Utah,
the Grand Canyon and surrounding areas in northern
Arizona, the Olympic Peninsula in Washington, the
Cascade Mountains in Washington, Oregon and California
3
Figure 1. Suitable gray wolf habitat in the contiguous United States as identied in 14 modeling studies.
regions of the country, but
wolves are dispersing into
this habitat. Wolves can
travel substantial distances
traversing diverse landscapes
when leaving their birth-
packs to seek mates and
territory of their own (Mech
and Boitani, 2003). The
most-recent and well-known
example is that of wolf OR-
7, who traveled more than
4,000 miles after dispersing
from his birth pack in
northeastern Oregon to travel
to California and back into
Oregon repeatedly during
2011-2014. He recently
found a mate, with whom
he has denned and produced
pups in southwestern Oregon
just north of the California
border. In order to quantify
and visually display these
dispersal events, we tabulated all known wolf dispersals
between 1981 and 2014 in which wolves dispersed
to areas and states outside of existing core recovery
areas (Appendix D). The dispersals we tabulated were
reported in newspaper stories, agency reports and other
sources, and for each dispersal event we attempted to
obtain a point of origin and endpoint. We identied
56 dispersal events in total, with an average dispersal
distance of 264 miles. This data shows that wolves have
and will continue to move into suitable habitat on the
West Coast, southern Rocky Mountains and Northeast,
where they need protection if they are going to survive
and establish populations (Figure 2). Indeed, with
protections under the Endangered Species Act, wolves
were able to move into Oregon and Washington from
both the northern Rockies and British Columbia and
form edgling populations.
Our data also shows dispersal events steadily
increased from 2000 to 2011, when populations were
steadily growing with endangered species protections
in place, and appear to have since declined now that
all states with substantial wolf populations have
enacted aggressive hunting and trapping seasons,
leading to population declines (Figure 3). This further
highlights the need for continued protection both in
4
areas that support source populations and in areas to
which wolves are dispersing.
V. Recovery of Wolves to Additional Areas is
Required by the Endangered Species Act
Unlike previous endangered species statutes, the
Endangered Species Act does not simply require
recovery of species to the point that they are not at
risk of global extinction. Indeed, the primary purpose
of the Act is to conserve the ecosystems upon which
endangered species depend (16 U.S.C. § 1531(b)).
Signicantly, the Act denes an endangered species as
any species in danger of extinction in all or a signicant
portion of its range (16 U.S.C § 1532(6)). This
means that a species need not be at risk of extinction
everywhere to qualify for protection, but rather only
in a signicant portion of range. Accordingly, it also
means that species cannot be considered recovered
until no longer endangered in any signicant portion of
range. As demonstrated by the 27 studies we reviewed,
wolves remain absent or at very low numbers over
signicant portions of their historic range where there
Figure 2. Dispersals by wolves to locations outside
of core federal recovery areas, 1981-2014.
numbered 1,691 in the northern Rockies, 3,669 in
the western Great Lakes, and 83 in the Southwest.i
According to the above studies, which collectively
examined hundreds of species, all existing wolf
populations are below minimum population sizes
considered necessary to ensure long-term survival.
Of further concern, wolf populations in both the
northern Rockies and Great Lakes are declining
in response to aggressive hunting and trapping
seasons enacted by individual states. In the northern
Rockies, the last population count showed a 9 percent
decline since federal delisting and in Minnesota,
the population declined by an estimated 25 percent
between 2008 and 2012.ii If these population declines
continue, risk to wolf populations will only increase.
Existing wolf populations are also below levels
considered necessary to avoid genetic inbreeding. A
number of studies have concluded that an “effective”
population size of 500 individuals is necessary to avoid
i For northern Rockies see: http://www.fws.gov/mountain-prairie/
species/mammals/wolf/annualrpt12/; for western Great Lakes see
http://www.fws.gov/midwest/wolf/aboutwolves/WolfPopUS.htm.
ii See: Ibid. and www.mndnr.gov/wolves
is extensive remaining habitat, including the Northeast,
southern Rocky Mountains, West Coast and elsewhere.
For this reason alone, wolves remain an endangered
species that continues to need the protections of the
Endangered Species Act.
VI. Existing Wolf Populations Are Not
Viable in the Absence of Additional
Population Expansion
The existing wolf populations in the northern Rocky
Mountains, western Great Lakes and Southwest are
below minimum viable population sizes sufcient
to ensure their survival (Shaffer, 1981; Reed et. al.,
2003, Traill et al. 2007). In an analysis of 102 species
including the gray wolf, Reed et al., (2003) estimated
a mean and median minimum viable population of
7,316 and 5,816 individuals respectively, concluding
that long-term persistence of wild populations
of animals, such as wolves, requires 7,000 adult
individuals. Likewise, Traill et al., (2007) combined
results from studies on 212 species, including the
gray wolf, nding that the median minimum viable
population was 4,169 individuals.
As of the end of 2013, the existing wolf populations
Figure 3. Annual gray wolf dispersal events to areas and states outside of federal core recovery areas.
5
VII. Recovering Wolves to Additional Areas
Is Necessary for Healthy, Functioning
Ecosystems
The loss of large carnivores is a global problem with
broad ecological consequences. Because of their
position at the top of food chains, large carnivores play
an inordinate role in shaping the structure and function
of diverse ecosystems (Estes et al. 2011, Ripple et
al., 2014). According to Ripple et al. (2014), nearly
two-thirds (61 percent) of large carnivore species
are considered threatened by the IUCN and most (77
percent) are declining. The extirpation of the gray wolf
across most of the American landscape is no exception
to this pattern and as elsewhere around the world, loss
of a top predator like the gray wolf has resulted in a
number of rippling ecological consequences that have
negatively impacted a broad range of species. This can
be inferred largely by studies showing positive trends
in a broad range of species following reintroduction of
wolves in the northern Rockies.
Studies following reintroduction of wolves to
Yellowstone National Park documented that wolves
had a profound and transformative impact on the
landscape that benetted a wide variety of species. In
particular, the reintroduction of wolves resulted in a
dramatic decrease in elk numbers and also potentially
forced them to move more (Barber-Meyer et al., 2008,
the effects of genetic inbreeding (Soule and Wilcox,
1980; Frankel and Soule, 1981; Soule, 1986; Franklin
and Frankham, 1998). Effective population size is
dened as the number of breeding individuals, rather
than total individuals, translating into a total population
of 2,500-5,000 individuals to maintain a total of 500
breeding individuals (Frankham, 1995). Gray wolves
in North America have already lost substantial genetic
diversity because of the severe reduction in their overall
historical numbers and range and further losses could
lower survival and reproduction further endangering
wolves (Leonard et al., 2005).
Loss of genetic diversity due to small population
size and historic declines is compounded by the
isolation of existing wolf populations (Soule, 1980).
The Mexican gray wolf, for example, is isolated from
all other wolf populations and the population in the
Greater Yellowstone ecosystem is largely isolated
from other wolves in the northern Rockies. This lack
of connectivity further increases the potential for
loss of genetic variation over time. Restoring wolves
to additional suitable habitat would create more
opportunity for connectivity between populations.
It would also increase the likelihood that wolves
dispersing from currently existing wolf populations
would be able to nd other wolves with whom to
mate, and thus contribute genetically to the health of
adjacent populations.
6
OR-11 courtesy ODFW
survival of pronghorn antelope fawns due to reduced
predation by coyotes (Berger et al., 2008). Carcasses
of elk killed by wolves provide food for a host of other
scavenger species, including but not limited to grizzly
bears, black bears, coyotes, eagles, ravens, magpies
and hundreds of species of beetles (Smith et al., 2003).
Wolf-kills may also provide a buffering effect against
climate change for carrion-feeders that depend on
carcasses for food. As warming temperatures result in
decreased winter severity, and thus a decreased die-off
of vulnerable animals that would otherwise succumb
to harsh weather, wolf-kills will provide the carcasses
scavengers need to survive (Wilmers and Getz, 2005).
The ecosystems of the southern Rocky Mountains,
Colorado Plateau, Grand Canyon, Cascade Mountains,
Adirondack Mountains, Sierra Nevada and elsewhere
would all benet from the return and recovery of
the gray wolf. It is not enough to restore the wolf
to small fragments of its historic range. Instead,
large carnivores like wolves should be restored to
population levels allowing them to once again be
“ecologically effective” – that is, a population that
has enough individuals and a wide enough geographic
distribution so that not just the species’ existence has
been reestablished but, also, its essential role in nature
(Soule et al., 2003; Carroll et al., 2006.)
Ripple and Beschta, 2012). Reduced elk browse in
turn has led to recovery of woody species, such as
cottonwood, aspen, willow and serviceberry (Ripple
and Beschta, 2012). This has fostered many benecial
ecosystem changes, from providing crucial nesting and
roosting sites for songbirds, to enhancing root strength
and thereby protecting streams from soil erosion,
to providing food and building sources for beavers
whose dams then create cool, deep ponds needed
by juvenile sh, and nally to facilitating growth of
berry-producing shrubs that provide food for grizzly
bears and other animals (Ripple and Beschta, 2004;
Hebblewhite et al., 2005; Weiss et al., 2007; Eisenberg
et al., 2013, Hollenbeck and Ripple, 2008, Ripple et
al., 2013).
Wolves prey on wild ungulates which are the most
vulnerable due to factors such as age, injury or ill-
health, allowing greater numbers of healthier, more
robust, and more alert animals to survive and pass
on their genes (Stahler et al, 2006). Wolves may also
prevent the spread of diseases among prey species
by culling sick animals before they infect others
(Wild et al., 2005). Wolves view coyotes as territorial
competitors and in some parts of Yellowstone wolves
have greatly decreased the coyote density. This has
led to increases in numbers of foxes and increased
7
Diamond pack female courtesy WDFW
VIII. Maintaining Federal Protections for
Wolves Is Essential Because States Cannot
Be Trusted to Conserve Existing Wolf
Populations or Protect Wolves Dispersing to
Other Areas
Following removal of Endangered Species Act
protections in the northern Rockies and western
Great Lakes, all of the states with substantial
wolf populations enacted aggressive hunting and
trapping seasons designed to drastically lower
populations, and indeed population declines are
occurring. In the three years since protections were
removed, nearly 3,000 wolves have been killed
through state-sanctioned “harvest” seasons. The
killing of so many wolves in such a short time
directly reflects the negative prejudices towards
wolves held by powerful minorities in all of these
states. These prejudices were the primary cause
of the extirpation of the wolf across significant
portions of its range and highlight why wolves
continue to need federal protections and a national
recovery plan.
Worse still, anti-wolf policies appear to be getting
more severe in most states where protections have
been removed. In Idaho, for example, wolf hunting
is allowed year round, including during breeding
season and has resulted in the death of at least 1,000
wolves and reduced the state’s wolf population by
around 23 percent from its 2008 peak. This not being
enough, the Idaho Department of Fish and Game in
January 2014 hired a bounty hunter to pack into the
Frank Church-River-of-No-Return Wilderness where
he killed nine wolves; has sent U.S. Department of
Agriculture/Wildlife Services’ airborne sharpshooters
into the Clearwater National Forest where 48 wolves
have been killed in six operations; and Gov. Butch
Otter this spring signed into law a bill that establishes
a wolf-control board and provides over $600,000
annually to kill most of Idaho’s remaining wolves.iii
In Montana, the state wildlife commission nearly
doubled the number of wolves that can be killed by
an individual hunter or trapper in 2013 compared
to 2012, and extended the wolf-killing season
through the middle of March (when wolves would
iii See: http://gazers.com/previously-endangered-wolves-can-now-
exterminated-idaho/
8
be pregnant.) In Wyoming, wolves were designated
a predatory animal that can be killed at anytime by
nearly any means, including killing pups in dens, in
nearly 85 percent of the state and designated the rest
of the state outside of Yellowstone and Grand Teton
National Parks, a trophy game area, where hunting of
wolves was permitted. This management was found
to be inadequate by a federal court in September,
2014 and Endangered Species Act protections were
reestablished, stopping the 2014-2015 hunt and killing
of wolves in the predatory zone.
In Minnesota, the state had promised in its state
wolf plan that there would be no hunting or trapping
of wolves for ve years post delisting, but instead
instituted wolf hunting and trapping immediately
following delisting. To date, at least 650 wolves
have been killed and the population declined by
25 percent between 2008-2012. Starting in 2012,
Wisconsin authorized wolf-hunting and trapping
that has to date resulted in killing of 374 wolves
with a goal of reducing the population by more
than half to 350 wolves from over 800. Wolves
are allowed to be hunted and trapped with the use
of hounds, night-hunting by articial lights, and
baiting, despite overwhelming public opposition
to any of these practices.iv Michigan’s governor
in 2013 signed a bill allowing its state department
of natural resources to institute hunting of wolves
despite citizens having collected over a quarter
of a million signatures to place a no-wolf-hunting
measure on the election-season ballot; a second
signature-collecting effort has resulted in a second
ballot measure to overturn the newly-signed wolf-
hunting law, but a pro-hunting ballot measure was
just passed by the legislature. Because the no-wolf
hunting ballot measure must be decided by the
voters in the November election, Michigan wolves
have received a temporary reprieve and there will be
no wolf-hunting season in Michigan this year. But if
the no-hunting measure does not pass, the legislative
bill will go into effect in March meaning Michigan’s
wolves will once again be facing legal harvest and
certain death. Finally, in South Dakota, the state
passed a law that classies wolves in the eastern half
of the state as “varmints” that can be shot on sight.
iv Wisconsin Department of Natural Resources 2013 wolf
hunting and trapping regulations; The Political Environment,
April 12, 2013
IX. Conclusion
In its rush to remove federal protections for gray wolves in most of the lower
48, the U.S. Fish and Wildlife Service relied on the states to adequately manage
and conserve the species. As these examples above demonstrate, however,
state management of wolves has been a political, rather than a science-based,
endeavor. In the three years states have had wolf-management authority, nearly
3,000 wolves have been killed from hunting and trapping, sanctioned by state
policies that fail to adequately consider the long-term viability or need for
further recovery of wolves.
The Service’s plan to now remove federal protections throughout most of the
remaining lower 48 states and allow states to fully manage wolves not only
jeopardizes the future of existing wolf populations it also makes it nearly
impossible for dispersing wolves to make their way to adjacent states to
establish new populations of wolves.
To achieve true, long-term, sustainable, recovery of the gray wolf, federal wolf
protections should be maintained and recovery plans developed, with the goal of
restoring connected, resilient, ecologically-effective wolf populations wherever
suitable wolf habitat exists. Formation of a recovery team made up of the many
highly-qualied wolf biologists and other scientists could ensure that considerable
recent science is brought to bear and ultimately produces a scientically and
legally defensible recovery strategy that species the conditions under which
wolves are downlisted and ultimately delisted in all or portions of the species’
range. Restoring wolves to these areas would fulll the ESA’s mandate to recover
threatened or endangered species throughout all signicant portions of their
ranges and to conserve the ecosystems upon which they depend.
Bibliography
9
Yellowstone wolf by doublejwebers / Flickr
Bibliography
Barber-Meyer, S.M., Mech, L.D. & White, P.J. 2008. Elk calf survival and mortality following wolf restoration
to Yellowstone National Park. Wildlife Monographs, 169, 1–30.
Berger, K.M., Gese, E.M., and J. Berger. 2008. Indirect effects and traditional trophic cascades: a test involving
wolves, coyotes, and pronghorn. Ecology 89(3): 818–828.
Carroll, Carlos, Phillips, M.K., Lopez-Gonzales, C.A. and Nathan H. Schumaker. 2006. Dening recovery goals
and strategies for endangered species using spatially- explicit
population models: the wolf as a case study. Bioscience 56:25-37.
Eisenberg, C., Seager, S.T. and D.E. Hibbs. 2013. Wolf, elk, and aspen food web relationships: Context and
complexity. Forest Ecol. Manage. (2013), http://dx.doi.org/10.1016/j.foreco.2013.01.014
Estes, J.A., Terborgh, J.A., Brashares, J.S., Power, M.E., Berger, J., Bond, W.J., Carpenter,
S.R., Essington, T.E., Holt, R.D., Jackson, J.B.C., Marquis, R.J., Oksanen, L., Oksanen,
T., Paine, R.T., Pikitich, E.K., Ripple, W.J., Sandin, S.A., Scheffer, M. 2011. Trophic
downgrading of planet Earth. Science 33, 301–306.
Frankel, O. H. and M. E. Soule. 1981. Conservation and Evolution. Cambridge University Press, New York,
N Y.
Frankham R. 1995. Effective population size/adult population size ratios in wildlife: a review. Genetical
Research 66: 95-107.
Franklin, I. R. and R. Frankham. 1998. How large must a population be to retain evolutionary potential? Animal
Conservation 1: 69-70.
Hebblewhite, M., C.A. White, C.G. Nietvelt, J.A. McKenzie, T.E. Hurd, J.M. Fryxell, S.E. Bayley, P.C. Paquet.
2005. Human activity mediates a trophic cascade caused by wolves. Ecology 86(8):2135-2144.
Hollenbeck, J., Ripple, W.J., 2008. Aspen patch and migratory bird relationships in the Northern Yellowstone
Ecosystem. Landsc. Ecol. 22, 1411–1425.
Leonard, J.A., C. Vila, and R.K. Wayne. 2005. Legacy lost: genetic variability and population size of extirpated
U.S. grey wolves (Canis lupus). Molecular Ecology. 14(1): 9-17.
Mech, L.D. and L. Boitani. Editors. 2003. Wolves: behavior, ecology and conservation. University of Chicago
Press. Chicago, IL.
Reed, D. H, J. J. O’Grady, B. W. Brook, J. D. Ballou and R. Frankham. 2003. Estimates of minimum viable
population sizes for vertebrates and factors inuencing those estimates. Biological Conservation 113: 23-34.
Ripple W.J. and R.L. Beschta. 2004. Wolves and the ecology of fear: can predation risk structure ecosystems?
BioScience 54(8):755-766.
Ripple W.J. and R.L. Beschta. 2012. Trophic Cascades in Yellowstone: The rst 15 years after wolf
reintroduction. Biological Conservation 145: 205–213
10
Ripple, W.J., Beschta, R.L., Fortin, J.K., and Robbins, C.T. 2013. Trophic Cascades from Wolves to Grizzly
Bears in Yellowstone. Journal of Animal Ecology, doi: 10.1111/1365-2656.12123.
Ripple, W.J., Estes, J.A., Beschta, R.L., Wilmers, C.C., Ritchie, E.G., Hebblewhite, M., Berger, J., Elmhagen,
E., Letnic, M., Nelson, M.P., Schmitz, O.J., Smith, D.W., Wallach, A.D. and A.J. Wirsing. 2014. Status and
ecological effects of the world’s largest carnivores. Science 343, 1241484.
Seton, E.T. 1929. Lives of Game Animals, Vol. 1: Cats, wolves, and foxes. Doubleday and Doran Co., New
York.
Shaffer, M.L. 1981. Minimum population sizes for species conservation. BioScience 31: 131-134.
Smith, Douglas W., R. 0. Peterson, and D. B. Houston. 2003. Yellowstone after wolves. Bioscience. 53(4):330-40.
Soule, M. E. and B. A. Wilcox. (Eds.) 1980. Conservation Biology, an evolutionary-ecological perspective.
Sinauer, Sunderland, MA.
Soule, M. E. (1980). “Thresholds for survival: maintaining tness and evolutionary potential.” Conservation
biology: an evolutionary-ecological perspective, M. E. Soule and B. A. Wilcox, eds., Sinauer Associates,
Sunderland, MA. 151-169.
Soule, M. E. 1986. (Ed.) Conservation Biology, the science of scarcity and diversity. Sinauer, Sunderland, MA.
Soule, M., Estes, J., Berger, J., and C. Del Rio. 2003. Ecological Effectiveness: Conservation Goals for
Interactive Species. Conservation Biology, 17(5): 1238-1250.
Stahler, D. R., D. W. Smith, and D. S. Guernsey. 2006. Foraging and feeding ecology of the gray wolf (Canis
lupus): Lessons from Yellowstone National Park, Wyoming, USA. Journal of Nutrition. 136: 1,923s-1,926s.
Traill, L. W., Corey J. A. Bradshaw, and Barry W. Brook. 2007. Minimum viable population size: a meta-
analysis of 30 years of published estimates. Biological Conservation 139: 159-166.
U.S. Fish and Wildlife Service. 1978. Reclassication of the Gray Wolf in the United States and Mexico, with
Determination of Critical Habitat in Michigan and Minnesota. Federal Register, V. 43(47): 9607-9615.
U.S. Fish and Wildlife Service. 2009. Final Rule to Identify the Western Great Lakes Populations of Gray
Wolves as a Distinct Population Segment; Final Rule to Identify the Northern Rocky Mountain Population of
Gray Wolf as a Distinct Population Segment; and To Revise the List of Endangered and Threatened Wildlife.
Federal Register, V. 74(62): 15069-15123.
U.S. Fish and Wildlife Service. 2011a. Reissuance of Final Rule To Identify the Northern Rocky Mountain
Population of Gray Wolf as a Distinct Population Segment and To Revise the List of Endangered and
Threatened Wildlife. Federal Register, V. 76(87): 25590-25592.
U.S. Fish and Wildlife Service. 2011b. Final Rule Revising the Listing of the Gray Wolf (Canis lupus) in the
Western Great Lakes. Federal Register, V. 76(249): 81666-81726.
U.S. Fish and Wildlife Service. 2013. Proposed Rule Removing the Gray Wolf (Canis lupus) from the List of
Threatened and Endangered Wildlife and Maintaining Protections for the Mexican Wolf (Canis lupus baileyi)
by Listing it as Endangered; Proposed Revision to the Nonessential Experimental Population of the Mexican
Wolf. Federal Register, V. 78(114): 35664-35719.
11
Weiss, A.E., Kroeger, T., Haney, J.C. and N. Fascione. 2007. Social and ecological benets of restored wolf
populations. Transactions of the 72nd North American Wildlife and Natural Resources Conference. Pp. 297-
319.
Wild, M. A., M. W. Miller, and N. T. Hobbs. 2005. Could wolves control chronic wasting disease?
Second International Chronic Wasting Disease Symposium. http://www.cwd-info.org/pdf/2005-cwd-
symposiumprogram.pdf.
Wilmers, C. C., and W. M. Getz. 2005. Gray wolves as climate change buffers in Yellowstone. PLoS Biology.
3(4):e92.
Young, S.P. and E.A. Goldman. 1944. The Wolves of North America. American Wildlands Institute,
Washington, D.C. Pp. 1-385.
Federal Endangered Species Act. 16 U.S.C. §1531-1544.
12
APPENDIX A: Wolf Habitat Modeling Literature Reviewed
Bednarz, J.C. 1989. An evaluation of the ecological potential of White Sands Missile Range to support a
reintroduced population of Mexican wolves. Endangered Species Report No. 19. U.S. Fish and Wildlife Service,
Albuquerque, NM. 96 pp.
Belongie, Cole. 2008. Using GIS to Create a Gray Wolf Habitat Suitability Model and to Assess Wolf Pack
Ranges in the Western Upper Peninsula of Michigan. Volume 10, Papers in Resource Analysis. 15pp. Saint
Mary’s University of Minnesota Central Services Press. Winona, MN.
Bennett, L.E. 1994. Colorado gray wolf recovery: A biological feasibility study. Final Report. U.S. Fish and
Wildlife Service and University of Wyoming Fish and Wildlife Cooperative research unit, Laramie, Wyoming,
USA. Available at: http://babel.hathitrust.org/cgi/pt?id=umn.31951p00672031a;view=1up;seq=146
Carroll, C. 2003. Wolf viability in the Northeastern United States and Southeastern Canada: A summary of new
research with implications for wolf recovery. Richmond, VT: the Wildlands Project. Special Paper No. 5
Carroll, Carlos. 2005. Carnivore Restoration in the Northeastern U.S. and Southeastern Canada: A Regional-
Scale Analysis of Habitat and Population Viability for Wolf, Lynx, and Marten (Report 2: Lynx and Marten
Viability Analysis). Wildlands Project Special Paper No. 6.
Richmond, VT: Wildlands Project. 46 pp.
Carroll, C., Noss, R.F., Schumaker, N.H., and P.C. Paquet. 2001. Is the return of the wolf, wolverine, and grizzly
bear to Oregon and California biologically feasible? In Large Mammal Restoration. Ecological and Sociological
Challenges in the 21st Century. Maher, D.S., Noss, R.F. and J.L. Larkins (Eds.) Island Press. Washington,
Covelo, London.
Carroll, C., Phillips, M.K., Schumaker, N.H. and D.W. Smith. 2003. Impacts of Landscape Change on Wolf
Restoration Success: Planning a Reintroduction Program Based on Static and Dynamic Spatial Models.
Conservation Biology. Vol. 17(2): 536–548.
Carroll, C. , Phillips, M.K. and C.A. Lopez-Gonzales. 2004. Spatial Analysis of Restoration Potential and
Population Viability of the Wolf (Canis lupus) in the Southwestern United States and Northern Mexico,
Prepared for the Turner Endangered Species Fund.
Carroll, Carlos, Phillips, M.K., Lopez-Gonzales, C.A. and Nathan H. Schumaker. 2006. Dening recovery goals
and strategies for endangered species using spatially- explicit
population models: the wolf as a case study. Bioscience 56:25-37.
Gehring, T.M. and B.A. Potter. 2005. Wolf Habitat Analysis in Michigan: An Example of the Need for Proactive
Land Management for Carnivore Species. Wildlife Society Bulletin, Vol. 33, No. 4 (Winter, 2005), pp. 1237-
1244.
Harrison, D.J. and T.B. Chapin. 1997. An Assessment of Potential Habitat for Eastern Timber Wolves in the
Northeastern United States and Connectivity with Occupied Habitat in Southeastern Canada. A summary report
and position paper prepared for the Wildlife Conservation Society.
13
Hearne, D., Lewis, K., Martin, M., Mitton, E. and C. Rocklen. 2003. Assessing the Landscape: Toward a Viable
Gray Wolf Population in Michigan and Wisconsin. School of Natural Resources and Management, University of
Michigan.
Houts, M.E. 2001. Modeling Gray Wolf Habitat in the Northern Rocky Mountains. Department of Geography.
University of Kansas.
Houts, M.E. 2003. Using logistic regression to model wolf habitat suitability in the northern Rocky Mountains.
World Wolf Congress, Banff, Alberta.
Johnson, T.B., Noel, D.C. and Ward, L.Z. 1992. Summary of Information on Four Potential
Mexican Wolf Reintroduction Areas in Arizona. Technical Report 23, Nongame and Endangered Wildlife
Program, Arizona Game and Fish Department. October.
Larsen T. and W.J. Ripple. 2006. Modeling gray wolf (Canis lupus) habitat in the Pacic Northwest. Journal of
Conservation Planning. Vol 2: 17-33.
Maletzke, B.T. and R.B. Wielgus. 2011. Development of wolf population models for RAMAS© analysis by the
Washington Department of Fish and Wildlife. In Press.
Mladenoff, D.J. and T.A. Sickley. 1998. Assessing potential gray wolf restoration in the northeastern
United States: A spatial prediction of favorable habitat and potential population levels. Journal of Wildlife
Management, V. 62: 1-10.
Mladenoff, D.J., Sickley, T.A., Haight, R.G. and A.P. Wydevan. 1995. A Regional Landscape Analysis and
Prediction of Favorable Gray Wolf Habitat in the Northern Great Lakes Region. Conservation Biology, Vol. 9,
No. 2 (Apr., 1995), pp. 279-294.
Mladenoff, D.J., Haight, R.G., Sickley, T.A. and A.P. Wydevan. 1997. Causes and Implications of Species
Restoration in Altered Ecosystems. BioScience, Vol. 47, No. 1 (Jan., 1997), pp. 21-31.
Mladenoff, D.J., Sickley, T.A. and A.P. Wydevan. 1999. Predicting Gray Wolf Landscape Recolonization:
Logistic Regression Models Vs. New Field Data. Ecological Applications, 9(1), 1999, pp. 37– 44.
Oakleaf, J.K., Murray, D.L., Oakleaf, J.R., Bangs, E.E., Mack, C.M., Smith, D.W., Fontaine, J.A., Jimenez,
M.D., Meier, T.J. and C.C. Niemeyer. 2006. Habitat Selection by Recolonizing Wolves in the Northern Rocky
Mountains of the United States. Journal of Wildlife Management 70(2):554-563.
Paquet, P.C., J.R. Strittholt and N.L. Stauss. 1999. Wolf reintroduction feasibility in the Adirondack Park.
Conservation Biology Institute, Corvallis, OR.
Potvin, M.J., Drummer, T.D., Vucetich, J.A., Beyer, Jr., E. and J.H. Hammill. 2005. Monitoring and Habitat
Analysis for Wolves in Upper Michigan. The Journal of Wildlife Management, Vol. 69, No. 4 (Oct., 2005), pp.
1660-1669.
Ratti, J.T., Weinstein, M., Scott, J.M., Wiseman, P.A., Gillesberg, A.M., Miller, C.A., Szepanski, M.M., and
Svencara, L.K. 2004. Feasibility of wolf reintroduction to Olympic Peninsula, Washington. Northwest Science
78:1-76.
14
Sneed, Paul G. 2001. The feasibility of gray wolf reintroduction to the Grand Canyon ecoregion. Endangered
Species Update; Vol. 18(4). pp. 153-158.
Wydevan, A.P., Fuller, T.K., Weber, W. and K. MacDonald. 1998. The Potential for Wolf Recovery in the
Northeastern United States via Dispersal from Southeastern Canada. Wildlife Society Bulletin, Vol. 26, No. 4,
Commemorative Issue Celebrating the 50th Anniversary of “A Sand County Almanac’’ and the Legacy of Aldo
Leopold (Winter, 1998), pp.776-784.
15
APPENDIX B: Predicted Wolf Habitat Area and Wolf Populations
Reference
Study Region
Method
Study Location
Suitable Wolf Habitat
(mi2)
# of Wolves
Region Could
Support
Bednarz 1989
Southwest
LANDSAT
White Sands Missile Range, NM
996
32-40
Belongie 2008
Midwest
GIS Overlay, Expert
Ranking
MI’s Upper Peninsula
4,846
-
Bennett 1994
S. Rockies
Unweighted Ranking
CO
12,000 - 25,000
407 814
Carroll 2003
Northeast
PATCH
ME (2025)
-
1,030
NH (2025)
-
68
NY (2025)
-
338
VT (2025)
-
50
Carroll et al. 2001
West Coast
GIS Index
OR & CA
48,494
-
Northeast OR
100
Southwest OR and Northern CA
190 470
Carroll et al. 2003
S. Rockies
-
-
>1,000
Carroll et al. 2004
Southwest
PATCH
Blue Range AZ/NM, Grand Canyon,
AZ, Mogollon Rim, AZ, San Juans,
CO, Vermejo/Carson, NM, UT
17,390 - 24,131
3,166
Carroll et al. 2006
Western U.S.
-
233,081
-
Gehring and Potter 2005
Midwest
Per Mladenoff et al. 1995
MI
849-1,634
40 105
Harrison and Chapin
1997
Northeast
ARC Info and GIS
ME
17,064
-
NY
5,644
-
NH
1,773
-
VT
954
-
MA
20
-
ME & NH
-
488
Adirondacks, NY
-
146
Hearne et al. 2003
Midwest
MI & WI
-
>1,000
Houts 2001
N. Rockies
Logistic Regression
Central ID, GYE, Western MT
27,751
-
Houts 2003
West Coast
Logistic Regression
OR & WA
9,730
-
N. Rockies
Central ID, GYE, Western MT
117,000
-
Johnson et al. 1992
Southwest
AZ
14,099
-
Larsen and Ripple 2006
N. Rockies
Logistic Regression
OR, ID, MT, WY
26,448
1,450
16
APPENDIX C: Predictive Modeling Parameters Used in 27 Wolf Habitat Suitability Models for the Lower 48 United States
Reference
Road density
Human density
or disturbance
Land
cover/use
Land
use/owner
Prey density
Prey
accessability
Prey
availability
Livestock
density
Climate or
snowfall
Slope or
elevation
Soil depth /
hydrology
Surface water
availability
Bednarz 1989
Belongie 2008
x
x
x
x
Bennett 1994
Carroll et al. 2001
x
x
x
x
x
Carroll et al. 2003
x
x
x
x
Carroll et al. 2004
x
x
x
x
x
Carroll et al. 2006
x
x
Carroll 2003
x
x
x
Carroll 2005
x
x
x
x
x
x
Gerhing and Potter 2005
x
Harrison and Chapin 1997
x
x
x
Hearne et al. 2003
x
x
x
Houts 2001
x
x
x
x
Houts 2003
x
x
Johnson et al. 1992
x
x
x
x
x
x
x
Larsen and Ripple 2006
x
x
x
x
x
x
x
Maletzke and Wielgus 2011
Mladenoff and Sickly 1998
x
x
Mladenoff et al. 1995
x
x
x
x
x
Mladenoff et al. 1997
x
x
x
x
Mladenoff et al. 1999
x
Oakleaf et al. 2006
x
x
x
x
x
x
x
Paquet et al. 1999
x
x
x
x
x
Potvin et al. 2005
x
x
Ratti et al. 2004
x
x
x
x
x
x
Sneed 2001
x
x
x
x
x
x
Wydevan et al. 1998
x
x
x
17
APPENDIX D: Tabulation of Dispersing Wolves, 1981-2014
Date
Reported End
Location
Estimated
Origin
Location
Estimated
Dispersal
Distance
(mi)
Outcome
Source
3/15/81 Brown County,
South Dakota Minnesota 139 Shot and
killed
Licht, D.S. and S.H. Fritts. 1998. Gray Wolf (Canis lupus) occurrences in the Dakotas. U.S.
Fish and Wildlife Service. Jamestown, ND: Northern Prairie Wildlife Research Center Online.
Accessed at: http://www.npwrc.usgs.gov/resource/mammals/wolves/index.htm
10/13/85 Dickey County,
North Dakota Minnesota 154 Shot and
killed
Licht, D.S. and S.H. Fritts. 1998. Gray Wolf (Canis lupus) occurrences in the Dakotas. U.S.
Fish and Wildlife Service. Jamestown, ND: Northern Prairie Wildlife Research Center Online.
Accessed at: http://www.npwrc.usgs.gov/resource/mammals/wolves/index.htm
6/4/86 Harding County,
South Dakota Unknown 349 Shot and
killed
Licht, D.S. and S.H. Fritts. 1998. Gray Wolf (Canis lupus) occurrences in the Dakotas. U.S.
Fish and Wildlife Service. Jamestown, ND: Northern Prairie Wildlife Research Center Online.
Accessed at: http://www.npwrc.usgs.gov/resource/mammals/wolves/index.htm
11/10/89 Brown County,
South Dakota Minnesota 158 Shot and
killed
Licht, D.S. and S.H. Fritts. 1998. Gray Wolf (Canis lupus) occurrences in the Dakotas. U.S.
Fish and Wildlife Service. Jamestown, ND: Northern Prairie Wildlife Research Center Online.
Accessed at: http://www.npwrc.usgs.gov/resource/mammals/wolves/index.htm
2/27/90 McIntosh County,
North Dakota Minnesota 185 Shot and
killed
Licht, D.S. and S.H. Fritts. 1998. Gray Wolf (Canis lupus) occurrences in the Dakotas. U.S.
Fish and Wildlife Service. Jamestown, ND: Northern Prairie Wildlife Research Center Online.
Accessed at: http://www.npwrc.usgs.gov/resource/mammals/wolves/index.htm
2/2/90 Walsh County,
North Dakota Minnesota 29 Shot and
killed
Licht, D.S. and S.H. Fritts. 1998. Gray Wolf (Canis lupus) occurrences in the Dakotas. U.S.
Fish and Wildlife Service. Jamestown, ND: Northern Prairie Wildlife Research Center Online.
Accessed at: http://www.npwrc.usgs.gov/resource/mammals/wolves/index.htm
2/27/91 Mountrail County,
North Dakota
Manitoba,
Canada 167 Shot and
killed
Licht, D.S. and S.H. Fritts. 1998. Gray Wolf (Canis lupus) occurrences in the Dakotas. U.S.
Fish and Wildlife Service. Jamestown, ND: Northern Prairie Wildlife Research Center Online.
Accessed at: http://www.npwrc.usgs.gov/resource/mammals/wolves/index.htm
12/1/91 Grant County,
South Dakota Minnesota 126 Shot and
killed
Licht, D.S. and S.H. Fritts. 1998. Gray Wolf (Canis lupus) occurrences in the Dakotas. U.S.
Fish and Wildlife Service. Jamestown, ND: Northern Prairie Wildlife Research Center Online.
Accessed at: http://www.npwrc.usgs.gov/resource/mammals/wolves/index.htm
18
12/22/91 Tripp County,
South Dakota Minnesota 329 Shot and
killed
Licht, D.S. and S.H. Fritts. 1998. Gray Wolf (Canis lupus) occurrences in the Dakotas. U.S.
Fish and Wildlife Service. Jamestown, ND: Northern Prairie Wildlife Research Center Online.
Accessed at: http://www.npwrc.usgs.gov/resource/mammals/wolves/index.htm
1/6/1992 Dunn County,
North Dakota Unknown 213 Shot and
killed
Licht, D.S. and S.H. Fritts. 1998. Gray Wolf (Canis lupus) occurrences in the Dakotas. U.S.
Fish and Wildlife Service. Jamestown, ND: Northern Prairie Wildlife Research Center Online.
Accessed at: http://www.npwrc.usgs.gov/resource/mammals/wolves/index.htm
Aug-93 Northeast Maine Unknown Unknown Shot and
killed1
Maine Wolf Coalition. Wolves in the Northeast. Accessed at:
http://mainewolfcoalition.org/wolves-in-the-northeast/; New York Times. 1996. Signs Suggest
a Return Of Timber Wolf to Maine. Accessed at:
http://www.nytimes.com/1996/12/22/us/signs-suggest-a-return-of-timber-wolf-to-maine.html
1994/95 Boyd County,
Nebraska
Western Great
Lakes DPS 300 Shot and
killed
U.S. Fish and Wildlife Service. 2011. Revisiting the Listing of the Gray Wolf in the Western
Great Lakes. Federal Register, Vol. 76, No. 249.
Nov-96 Eastern Maine Unknown Unknown Shot and
killed
Maine Wolf Coalition. Wolves in the Northeast. Accessed at:
http://mainewolfcoalition.org/wolves-in-the-northeast/; New York Times. 1996. Signs Suggest
a Return Of Timber Wolf to Maine. Accessed at:
http://www.nytimes.com/1996/12/22/us/signs-suggest-a-return-of-timber-wolf-to-maine.html
Nov-98 Glover, Vermont Unknown Unknown Shot and
killed
Maine Wolf Coalition. Wolves in the Northeast. Accessed at:
http://mainewolfcoalition.org/wolves-in-the-northeast/; Urbigkit, C. 2007. Wolf killed in
Vermont. Pinedale Online! Accessed at:
http://www.pinedaleonline.com/news/2007/10/WolfkilledinVermont.htm
2001 Harding County,
South Dakota
Western Great
Lakes DPS 400 Killed U.S. Fish and Wildlife Service. 2011. Revisiting the Listing of the Gray Wolf in the Western
Great Lakes. Federal Register, Vol. 76, No. 249.
Dec-01 Day, New York Unknown Unknown Shot and
killed (MC)
Maine Wolf Coalition. Wolves in the Northeast. Accessed at:
http://mainewolfcoalition.org/wolves-in-the-northeast/; Nearing, B. 2011. A century later, the
wild wolf returns: Animal shot a decade ago hints at the arrival of predator in New York.
Times Union. Accessed at: http://www.timesunion.com/local/article/A-century-later-the-wild-
wolf-returns-2222681.php
Feb-02
Pend Oreille
County,
Washington
Northwestern
Montana Unknown Moved into
B.C.
Wiles, G.J., H.L. Allen, and G.E. Hayes. 2011. Wolf conservation and management plan for
Washington. Washington Department of Fish and Wildlife, Olympia, Washington. 297 pp.
19
10/23/02
Outside of Trenton,
Grundy County,
Missouri
Ironwood,
Gogebic
County,
Michigan
470 Shot and
killed
Michigan Department of Natural Resources. 2008. Michigan Wolf Management Plan. Wildlife
Division Report No. 3484. Accessed at:
http://www.michigan.gov/documents/dnr/Draft_Wolf_Management_Plan_030708_227742_7.
pdf; Beringer, J. Personal communication with Jeff Beringer, Resource Scientist, Missouri
Department of Conservation. May 9, 2013.
Dec-02 Henry, Marshall
County, Illinois Wisconsin 200 Shot and
killed (MC)
University of Illinois. 2013. Wildlife Directory: Gray Wolf (Canis lupus). Accessed at:
http://web.extension.illinois.edu/wildlife/directory_show.cfm?species=wolf; Kath, J.A. 2013.
Personal Communication with Joseph A. Kath, Endangered Species Manager, Illinois
Department of Natural Resources. May 15, 2013.
12/15/02 Spalding, Greeley
County, Nebraska
Western Great
Lakes DPS 350 Shot and
killed
U.S. Fish and Wildlife Service. 2003. Status of Gray Wolf Recovery, Weeks of 3/28 to 4/04,
2003. Weekly Report, Gray Wolves in the Northern Rocky Mountains. Accessed at:
http://www.fws.gov/mountain-prairie/species/mammals/wolf/WeeklyRpt03/wk04042003.htm
2002 Morgan, Utah Yellowstone
NP 240
Trapped and
released in
Yellowstone
Hollenhorst, J. 2002. Wolf Capture in Utah Ignites Controversy. KSL-TV. Accessed at:
http://web.ksl.com/dump/news/cc/local/wolf_return.php
2003
Southwest (SW 1/4
Sec. 10, T19N,
R13E) Randolph
County, Indiana
Jackson
County,
Wisconsin
428 Found dead
Wisconsin Department of Natural Resources. 1999. Wisconsin Wolf Management Plan.
Madison, Wisconsin. Accessed at: http://dnr.wi.gov/files/pdf/pubs/er/er0099.pdf;
http://www.predatormastersforums.com/forums/ubbthreads.php?ubb=showflat&Number=8926
1
6/7/04 I-70, 30 mi west of
Denver, Colorado
Northwest
corner of
Yellowstone
NP
446 Killed by
motor vehicle
U.S. Fish and Wildlife Service. 2004. News Release: Preliminary Necropsy Results For Gray
Wolf Found Dead Near Denver, Colorado. U.S. Fish and Wildlife Mountain-Prairie Region,
Lakewood, Colorado. Accessed at: http://www.fws.gov/mountain-prairie/pressrel/04-43.htm
Oct-04 Lower Peninsula,
Michigan
Upper
Peninsula,
Michigan
Unknown Killed U.S. Fish and Wildlife Service. 2011. Revisiting the Listing of the Gray Wolf in the Western
Great Lakes. Federal Register, Vol. 76, No. 249.
2/17/05
Chain O'Lakes
State Park, Lake
County, Illinois
Wisconsin Unknown Killed by
motor vehicle
University of Illinois. 2013. Wildlife Directory: Gray Wolf (Canis lupus). Accessed at:
http://web.extension.illinois.edu/wildlife/directory_show.cfm?species=wolf; Kath, J.A. 2013.
Personal Communication with Joseph A. Kath, Endangered Species Manager, Illinois
Department of Natural Resources. May 15, 2013.
Dec-05 New Canton, Pike
County, Illinois
Central
Wisconsin 300 Shot and
killed
U.S. Fish and Wildlife Service. 2011. Revisiting the Listing of the Gray Wolf in the Western
Great Lakes. Federal Register, Vol. 76, No. 249; University of Illinois. 2013. Wildlife
Directory: Gray Wolf (Canis lupus). Accessed at:
http://web.extension.illinois.edu/wildlife/directory_show.cfm?species=wolf; Young, C. 2006.
Wild wolf killed in Pike County Illinois. Wolf Saga. Accessed at:
http://wolfsaga.blogspot.com/2006/02/wild-wolf-killed-in-pike-county.html; Kath, J.A. 2013.
Personal Communication with Joseph A. Kath, Endangered Species Manager, Illinois
Department of Natural Resources. May 15, 2013.
20
Apr-06 Sturgis, South
Dakota
Yellowstone
NP 300 Killed by
motor vehicle
Maughan, R. 2006. Wolf hit on I-90 near Sturgis, SD last April was a Yellowstone area wolf.
Wolf Report 8-15-2006. Accessed at: http://www.forwolves.org/ralph/sturgis-wolf.htm; Stark,
M. 2007. Yellowstone wolf hit near Sturgis. The Billings Gazette. Accessed at:
http://helenair.com/news/article_cee1229e-ec91-575c-a7ea-30287aac9b33.html
Oct-06 North Troy,
Vermont Unknown Unknown Shot and
killed
Maine Wolf Coalition. Wolves in the Northeast. Accessed at:
http://mainewolfcoalition.org/wolves-in-the-northeast/; Urbigkit, C. 2007. Wolf killed in
Vermont. Pinedale Online! Accessed at:
http://www.pinedaleonline.com/news/2007/10/WolfkilledinVermont.htm
2006 Tremonton, Utah
Northern
Rocky
Mountain DPS
Unknown Killed
U.S. Fish and Wildlife Service. 2007. Rocky Mountain Wolf Recovery 2006 Annual Report.
C.A. Sime and E.E. Gangs, eds. USFWS, Ecological Services, 585 Shepard Way, Helena,
Montana. 59601. 235 pp.
Oct-07 Shelburne,
Massachusetts Unknown Unknown Shot and
killed
Maine Wolf Coalition. Wolves in the Northeast. Accessed at:
http://mainewolfcoalition.org/wolves-in-the-northeast/; Reitz, S. 2008. Rare Gray Wolf
Appears in Western Massachusetts. National Geographic News. Accessed at:
http://news.nationalgeographic.com/news/2008/03/080305-AP-wolf-return.html
2/19/08 Lena, Illinois Western Great
Lakes DPS Unknown Shot and
killed (MC)
University of Illinois. 2013. Wildlife Directory: Gray Wolf (Canis lupus). Accessed at:
http://web.extension.illinois.edu/wildlife/directory_show.cfm?species=wolf; Kath, J.A. 2013.
Personal Communication with Joseph A. Kath, Endangered Species Manager, Illinois
Department of Natural Resources. May 15, 2013.
2008 Okanogan County,
Washington
"Coastal B.C.
and NE B.C.,
NW Alberta, or
reintroduced
populations in
central ID and
GYE”
Unknown Unknown Wiles, G.J., H.L. Allen, and G.E. Hayes. 2011. Wolf conservation and management plan for
Washington. Washington Department of Fish and Wildlife, Olympia, Washington. 297 pp.
Jul-08 Twisp, Washington
Coastal/Southe
rn British
Columbia
Unknown Unknown
U.S. Fish and Wildlife Service. 2011. Rocky Mountain Wolf Recovery 2010 Interagency
Annual Report. C.A. Sime and E.E. Bangs, eds. USFWS, Ecological Services, 585 Shepard
Way, Helena, Montana, 59601.
2009 Kane County,
Illinois Unknown Unknown Shot and
killed (MC)
University of Illinois. 2013. Wildlife Directory: Gray Wolf (Canis lupus). Accessed at:
http://web.extension.illinois.edu/wildlife/directory_show.cfm?species=wolf; Kath, J.A. 2013.
Personal Communication with Joseph A. Kath, Endangered Species Manager, Illinois
Department of Natural Resources. May 15, 2013.
Apr-09 South of Meeker,
Colorado
South of
Bozeman,
Montana
400
Killed by
Compound
1080
The Southwest Environmental Center. 2011. Lone wolf travels 3,000 miles before being
poisoned. Accessed at: http://www.wildmesquite.org/news/lone-wolf-travels-3000-miles-
being-poisoned/071511
21
May-09
Pend Oreille
County,
Washington
Northwestern
Montana/north
ern Idaho
Unknown Unknown Wiles, G.J., H.L. Allen, and G.E. Hayes. 2011. Wolf conservation and management plan for
Washington. Washington Department of Fish and Wildlife, Olympia, Washington. 297 pp.
Mar-10
Bellevue,
Sandusky County,
Ohio
Unknown Unknown Shot and
killed
Butterworth, S. 2013. Personal communication with Scott Butterworth, District Manager,
Wildlife District Two, Ohio Department of Natural Resources. May 14, 2013.;
http://www.toledoblade.com/StevePollick/2010/03/19/Wolf-shooting-piques-curiosity.html
Jul-10 Rich County, Utah Unknown Unknown Shot and
killed
Linnell, M. 2013. Personal communication with Mike Linnell, State Director, Utah, USDA-
Wildlife Services. May 10, 2013.
2010 Cache County,
Utah
Northern
Rocky
Mountain DPS
Unknown
Shot and
killed in
Idaho
Love, C. 2010. Wolf Range Expands into Utah. Field and Stream. Accessed at:
http://www.fieldandstream.com/blogs/hunting/2010/07/wolf-range-expands-utah
2010
12 miles northeast
of Carrolton,
Carroll County,
Missouri
Western Great
Lakes DPS Unknown Shot and
killed (MC)
Jerek, J. 2013. DNA shows hunter-shot canine from October to be wandering wolf. Missouri
Department of Conservation. Accessed at: http://mdc.mo.gov/newsroom/dna-shows-hunter-
shot-canine-october-be-wandering-wolf; Beringer, J. Personal communication with Jeff
Beringer, Resource Scientist, Missouri Department of Conservation. May 9, 2013.
2011 Western
Washington
Northern
Rocky
Mountain DPS
Unknown
Two packs
established
outside of
NRM DPS
U.S. Fish and Wildlife Service. 2012. Northern Rocky Mountain Wolf Recovery Program
2011 Interagency Annual Report. M.D. Jimenez and S.A. Becker, eds. USFWS, Ecological
Services, 585 Shepard Way, Helena, Montana, 59601.
2011
Southeast Jo
Daviess County,
Illinois
Unknown Unknown Shot and
killed (male)
University of Illinois. 2013. Wildlife Directory: Gray Wolf (Canis lupus). Accessed at:
http://web.extension.illinois.edu/wildlife/directory_show.cfm?species=wolf; Kath, J.A. 2013.
Personal Communication with Joseph A. Kath, Endangered Species Manager, Illinois
Department of Natural Resources. May 15, 2013.
2011
Southeast Jo
Daviess County,
Illinois
Unknown Unknown
Shot and
killed
(female)
University of Illinois. 2013. Wildlife Directory: Gray Wolf (Canis lupus). Accessed at:
http://web.extension.illinois.edu/wildlife/directory_show.cfm?species=wolf; Kath, J.A. 2013.
Personal Communication with Joseph A. Kath, Endangered Species Manager, Illinois
Department of Natural Resources. May 15, 2013.
Jan-11 Hillsboro, North
Dakota Unknown Unknown Shot and
killed (MC)
Associated Press. 2011. Federally protected gray wolf shot in North Dakota. Twin Cities
Pioneer Press. Accessed at: http://www.twincities.com/news/ci_17555251
Oct-11 Clinton County,
Missouri
Western Great
Lakes DPS Unknown Shot and
killed (MC)
Beringer, J. Personal communication with Jeff Beringer, Resource Scientist, Missouri
Department of Conservation. May 9, 2013; Leonard, J. 2012. Gower man unknowingly bags
wolf. News-Press Now. Accessed at: http://www.newspressnow.com/sports/outdoors/
article_917229af-fbd3-5ba4-9386-05f9e928cec9.html
22
12/28/11 Northern California
Northeastern
Oregon
(Imnaha pack)
350
Travelled
back to
Oregon in
March 2013
Oregon Department of Fish and Wildlife. 2013. Wolves in Oregon: Wolf Program Updates.
Accessed at: http://www.dfw.state.or.us/wolves/; California Department of Fish and Wildlife.
Wildlife and Habitat Management: OR-7 - A Lone Wolf's Story. Accessed at:
http://www.dfg.ca.gov/wildlife/nongame/wolf/OR7story.html
Feb-12 Custer County,
South Dakota
Western Great
Lakes DPS Unknown Killed
Woster, K. 2012. Wolf killed near Custer likely from Great Lakes population. Rapid City
Journal. Accessed at: http://rapidcityjournal.com/news/wolf-killed-near-custer-likely-from-
great-lakes-population/article_92dc1eb8-6be8-11e1-8ce3-001871e3ce6c.html; Custer County
Chronicle Online. 2012. Wolf killed near Custer. Accessed at:
http://www.custercountynews.com/cms/news/story-427443.html
May-12 Pine Ridge, South
Dakota
Southeast
Yellowstone
NP
400
Found dead,
likely hit by
motor vehicle
Woster, K. 2012. Wolf found near Pine Ridge migrated from Yellowstone. Rapid City Journal.
Accessed at: http://rapidcityjournal.com/news/wolf-found-near-pine-ridge-migrated-from-
yellowstone/article_f6d01210-9f07-11e1-a76d-001a4bcf887a.html
Oct-12
Franklin Island
Conservation Area,
Howard County,
Missouri
Western Great
Lakes DPS Unknown Shot and
killed (MC)
Jerek, J. 2013. DNA shows hunter-shot canine from October to be wandering wolf. Missouri
Department of Conservation. Accessed at: http://mdc.mo.gov/newsroom/dna-shows-hunter-
shot-canine-october-be-wandering-wolf; Beringer, J. Personal communication with Jeff
Beringer, Resource Scientist, Missouri Department of Conservation. May 9, 2013.
Dec-12 Trego County,
Kansas
Western Great
Lakes DPS Unknown Shot and
killed (MC)
Kansas Department of Wildlife, Parks and Tourism. 2013. Weekly News: Wolf Found In
Kansas. Accessed at: http://kdwpt.state.ks.us/KDWPT-Info/News/Weekly-News/1-31-
13/WOLF-FOUND-IN-KANSAS; Peek, M. 2013. Personal Communication with Matt Peek,
Wildlife Research Biologist, Kansas Department of Wildlife, Parks & Tourism. May 10, 2013.
Dec-12 Coleta, Whiteside
County, Illinois Unknown Unknown Trapped and
released
University of Illinois. 2013. Wildlife Directory: Gray Wolf (Canis lupus). Accessed at:
http://web.extension.illinois.edu/wildlife/directory_show.cfm?species=wolf; Kath, J.A. 2013.
Personal Communication with Joseph A. Kath, Endangered Species Manager, Illinois
Department of Natural Resources. May 15, 2013.
Mar-13
Apple Canyon
Lake, Jo Daviess
County, Illinois
Wisconsin 250 Found dead
University of Illinois. 2013. Wildlife Directory: Gray Wolf (Canis lupus). Accessed at:
http://web.extension.illinois.edu/wildlife/directory_show.cfm?species=wolf; Kath, J.A. 2013.
Personal Communication with Joseph A. Kath, Endangered Species Manager, Illinois
Department of Natural Resources. May 15, 2013.
Dec-13 La Salle County,
IL Unknown Unknown Killed by
vehicle
University of Illinois. 2013. Wildlife Directory: Gray Wolf (Canis lupus). Accessed at:
http://web.extension.illinois.edu/wildlife/directory_show.cfm?species=wolf; Kath, J.A. 2013.
Personal Communication with Joseph A. Kath, Endangered Species Manager, Illinois
Department of Natural Resources. May 15, 2013.
Mar-14
Munfordville,
Kentucky (Hart
County)
Western Great
Lakes DPS 750 Shot and
killed
Associated Press. 2013. Officials confirm gray wolf killed in Ky. Accessed at:
http://www.wkyt.com/home/headlines/officials-confirm-gray-wolf-killed-in-ky-
219749481.html
23
MC Wolf was mistaken for coyote when shot.
1 shot by bear hunter who was prosecuted by USFWS
Feb-14 Fairbank, Iowa
(Buchanan County)
Western Great
Lakes DPS 250 Shot and
killed (MC)
Love, Orlan. 2014. First wolf in Iowa in 89 years killed in Buchanan County. Accessed at:
http://www.kcrg.com/subject/news/first-wolf-in-iowa-in-89-years-killed-in-buchanan-county-
20140506
May-14 Jones County, Iowa
Awaiting info
from Iowa
DNR
Unknown Shot and
killed (MC)
Love, Orlan. 2014. http://thegazette.com/subject/environment/nature/endangered-
species/another-wolf-slain-in-iowa-20140717
24
ResearchGate has not been able to resolve any citations for this publication.
Conference Paper
Full-text available
The foraging and feeding ecology of gray wolves is an essential component to understanding the role that top carnivores play in shaping the structure and function of terrestrial ecosystems. In Yellowstone National Park (YNP), predation studies on a highly visible, reintroduced population of wolves are increasing our understanding of this aspect of wolf ecology. Wolves in YNP feed primarily on elk, despite the presence of other ungulate species. Patterns of prey selection and kill rates in winter have varied seasonally each year from 1995 to 2004 and changed in recent years as the wolf population has become established. Wolves select elk based on their vulnerability as a result of age, sex, and season and therefore kill primarily calves, old cows, and bulls that have been weakened by winter, Summer scat analysis reveals an increased variety in diet compared with observed winter diets, including other ungulate species, rodents, and vegetation. Wolves in YNP hunt in packs and, upon a successful kill, share in the evisceration and consumption of highly nutritious organs first, followed by major muscle tissue, and eventually bone and hide. Wolves are adapted to a feast-or-famine foraging pattern, and YNP packs typically kill and consume an elk every 2-3 d. However, wolves in YNP have gone without fresh meat for several weeks by scavenging off old carcasses that consist mostly of bone and hide. As patterns of wolf density, prey density, weather, and vulnerability of prey change, in comparision with the conditions of the study period described here, we predict that there will also be significant changes in wolf predation patterns and feeding behavior.
Technical Report
Full-text available
This Wolf Conservation and Management Plan summarizes the historical and current distribution and abundance of wolves in Washington state and describes factors that affect wolf recovery. It provides recovery goals for downlisting and delisting the species and prescribes strategies to achieve these goals, including management of conflicts with livestock and ungulates. As such, it serves as the recovery plan for wolves in Washington.
Article
Full-text available
Large carnivores face serious threats and are experiencing massive declines in their populations and geographic ranges around the world. We highlight how these threats have affected the conservation status and ecological functioning of the 31 largest mammalian carnivores on Earth. Consistent with theory, empirical studies increasingly show that large carnivores have substantial effects on the structure and function of diverse ecosystems. Significant cascading trophic interactions, mediated by their prey or sympatric mesopredators, arise when some of these carnivores are extirpated from or repatriated to ecosystems. Unexpected effects of trophic cascades on various taxa and processes include changes to bird, mammal, invertebrate, and herpetofauna abundance or richness; subsidies to scavengers; altered disease dynamics; carbon sequestration; modified stream morphology; and crop damage. Promoting tolerance and coexistence with large carnivores is a crucial societal challenge that will ultimately determine the fate of Earth’s largest carnivores and all that depends upon them, including humans.
Article
Full-text available
The reintroduction of the gray wolf into the Northern Rocky Mountains has created many difficult management issues; ranchers fear for their livestock, hunters worry about game populations, ecologists and biologists support the reintroduction, and resource management agencies are caught in the middle. To date (2000), the one hundred plus wolves in the Yellowstone National Park area and approximately 200 more in Idaho and Montana have been monitored and managed using action/reaction techniques. Consequently, as wolves disperse through these areas, little preparation or planning has been conducted due to a lack of information about wolf locations, movements, and habitat preferences. To improve the management of the gray wolf in the Northern Rocky Mountains, and to assist with pro-active planning, a geographic information system (GIS) was developed to create a wolf habitat suitability model. There were two main objectives to this project: the first was to identify the most effective mapping unit (Idaho Game Management Units, 33x33 km grid, 16x16 km grid) for modeling wolf habitat, and the second was to analyze four landscape variables (land cover, land ownership, road density, elk density) using logistic regression to predict wolf habitat suitability. Habitat models were built using data from Idaho, then the best model was tested using data from Montana and Wyoming for out-of- sample validation. Results indicated that a 33 x33 kilometer grid worked best for modeling wolf habitat, and that road density and land cover were the most influential landscape variables for determining wolf habitat suitability. Overall accuracies of 83%, 89%, and 75% were achieved for predicting the presence/absenceof wolves in Idaho, Montana, and Wyoming, respectively. The resulting habitat suitability maps can assist management,agencies in the identification of potential wolf habitats, areas where human/wolf conflicts are likely to occur, and areas that should be considered essential wolf habitat, thus contributing to the improved management,and protection of the gray wolf in the Northern Rocky Mountains.
Article
During 1991, Booth Gardner (Governor of Washington at that time) called upon Washington State residents to pressure relevant agencies to work toward wolf reintroduction to the Olympic Peninsula. Six years later, Representative Norm Dicks, Washington, and Defenders of Wildlife President, Roger Schlickeisen, announced plans for a feasibility study. During February 1998, the U.S. Fish and Wildlife Service (USFWS) distributed a request for proposals for the study, and a cooperative agreement for the study was established between the USFWS, the Idaho Cooperative Research Unit, and the University of Idaho in April 1998. We identified and examined factors that influence feasibility of reintroducing wolves to the Olympic Peninsula, Washington. From review of the literature and interviews with interested parties we identified the following relevant factors: (1) current and historical status, (2) cultural and spiritual considerations, (3) habitat suitability, (4) demography and distribution of potential prey, (5) adequacy of habitat and prey for supporting a viable population, (6) future projections for an established population of wolves, (7) socio-economic factors, and (8) data limitations and needs as relevant factors. Our analysis was constrained from a lack of relevant data regarding prey populations for much of the region. Almost all lands outside of Olympic National Park had road densities considered too restrictive for long-term occupation by wolves, thus we restricted analyses mostly to Park lands. Based on previously published models, we predicted a wolf population of 56 animals causing little to moderate negative impact on ungulate populations, and minimal livestock depredation. We also predicted little domestic animal interaction, minimal disease concerns, and a negligible risk of direct aggression toward humans. Although we concluded that reintroduction of wolves to the Park is feasible for establishment of a marginally viable population, we cautioned that such action may not be prudent. That is, we predicted substantial negative political, social, and financial consequences. Key concerns included potential loss of some isolated and culturally important elk herds, negative reactions to wolves expressed by local residents and sportspersons, concerns regarding livestock and pet depredation, and long-term funding of an appropriate wolf-management program.
Article
The northeastern United States was previously identified under the U.S. Endangered Species Act (ESA) as a potential location for restoration of a population of the endangered eastern timber wolf or gray wolf (Canis lupus). The gray wolf has been protected under the ESA since 1974. We used Geographic Information Systems (GIS) and a logistic regression model based on regional road abundance to estimate that the Northeastern states from Upstate New York to Maine contain >77,000 km2 of habitat suitable for wolves. Using current habitat distribution and available ungulate prey (deer and moose), we estimate the area is capable of sustaining a population of approximately 1,312 wolves (90% CI = 816-1,809). This estimate is equivalent to new, much higher potentials estimated for northern Wisconsin and Upper Michigan, where wolves are rapidly recovering in the U.S. Midwest. Potential wolf densities vary from a low of <12/1,000 km2 in the Adirondack Region of Upstate New York, where prey densities are lowest, to 20-25/1,000 km2 in northern Maine and New Hampshire. A contiguous area of favorable habitat from Maine to northeastern Vermont (>53,500 km2) is capable of supporting approximately 1,070 wolves (90% CI = 702-1,439). Such large areas are increasingly rare and important for wolf recovery if populations large enough to have long-term evolutionary viability are to be maintained within the United States. However, large-scale restoration of a top carnivore like the wolf has other consequences for overall forest biodiversity in eastern forests because wolf recovery is dependent on high levels of ungulate prey, which in turn have other negative effects on the ecosystem. In the United States, planning for wolf restoration in the Northeast should take advantage of experience elsewhere, especially the upper Midwest.
Article
We explored multiple linkages among grey wolves (Canis lupus), elk (Cervus elaphus), berry-producing shrubs and grizzly bears (Ursus arctos) in Yellowstone National Park. We hypothesized competition between elk and grizzly bears whereby, in the absence of wolves, increases in elk numbers would increase browsing on berry-producing shrubs and decrease fruit availability to grizzly bears. After wolves were reintroduced and with a reduced elk population, we hypothesized there would be an increase in the establishment of berry-producing shrubs, such as serviceberry (Amelanchier alnifolia), which is a major berry-producing plant. We also hypothesized that the percentage fruit in the grizzly bear diet would be greater after than before wolf reintroduction. We compared the frequency of fruit in grizzly bear scats to elk densities prior to wolf reintroduction during a time of increasing elk densities (1968-1987). For a period after wolf reintroduction, we calculated the percentage fruit in grizzly bear scat by month based on scats collected in 2007-2009 (n = 778 scats) and compared these results to scat data collected before wolf reintroduction. Additionally, we developed an age structure for serviceberry showing the origination year of stems in a northern range study area. We found that over a 19-year period, the percentage frequency of fruit in the grizzly diet (6231 scats) was inversely correlated (P < 0·001) with elk population size. The average percentage fruit in grizzly bear scats was higher after wolf reintroduction in July (0·3% vs. 5·9%) and August (7·8% vs. 14·6%) than before. All measured serviceberry stems accessible to ungulates originated since wolf reintroduction, while protected serviceberry growing in a nearby ungulate exclosure originated both before and after wolf reintroduction. Moreover, in recent years, browsing of serviceberry outside of the exclosure decreased while their heights increased. Overall, these results are consistent with a trophic cascade involving increased predation by wolves and other large carnivores on elk, a reduced and redistributed elk population, decreased herbivory and increased production of plant-based foods that may aid threatened grizzly bears.