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In a recent analysis Woodroffe (2000) found a positive relationship between historical patterns of large carnivore extinction probability and human population density. However, much of the data in this analysis came from a period when carnivore extermination was a management objective. In order to explore the hypothesis that large carnivores can persist at high human densities when the management regime is more favourable we have repeated the analysis using up-to-date data from North America and Europe. In North America we found that large carnivore populations have increased after favourable legislation was introduced, despite further increases in human population density. In Europe we found no clear relationship between present carnivore distribution and human population density. We therefore believe that the existence of effective wildlife management structures is more important than human density per se.
Predators and people: conservation of large carnivores is
possible at high human densities if management policy
is favourable
In our modern and crowded world, large carnivores are
among the most challenging taxonomic groups to con-
serve (Mech, 1995). Their massive area requirements
and predatory behaviour (on both wild prey and live-
stock) lie at the core of the problem (Nowell & Jackson,
1996). In addition, their populations have been dramat-
ically reduced during the last 200 years. However, their
decline has not been uniform throughout the world, and
while some populations have been exterminated, others
have survived to a far greater degree. In a recent analy-
sis of historic trends, Woodroffe (2000) attempted to
explain some of this variation by examining the rela-
tionship between large carnivore extinction probability
and increasing human population density. For a variety
of species, Woodroffe found a clear positive relationship
between human density and extinction probability.
However, we believe that while being a fair analysis of
past processes her analysis does not present an accurate
picture of the ability for large carnivores to persist in the
modern world under favourable management regimes.
Instead, against a background of European experience
and an examination of more modern North American
data (which were not covered by Woodroffe), we pre-
sent the thesis that large carnivore persistence is more
adequately explained by management policy, and the
enforcement of this policy, than human population den-
sity per se.
The North American extinction data used by Woodroffe
(2000) stem from the late 1800s and early 1900s. During
this entire period the widespread social agenda, and
politically sanctioned policy, was to eradicate large car-
nivores (Mech, 1970; Brown, 1983; chapters in Novak
et al., 1987). Bounties were offered at various times by
county, state and federal administrations. In addition,
large amounts of federal money were used to support
professional hunters who used all available methods (e.g.,
traps, poison, aerial hunting) to kill carnivores. During
the same time period, there was widespread conversion
of forest habitats to farmland, and decimation of the prey
base of native ungulates on which large carnivores
depend. As human population size also correlates with
time, the data analyzed by Woodroffe (2000) describe
the progressive success of this extermination policy, and
the temporal progression of immigrant expansion into
relatively unsettled territory, rather than a simple causal
density-dependent relationship between human density
and carnivore extinction. Woodroffe’s critical human
density appears to be a measure of the effort that humans
must make in order to exterminate large carnivores
when they are trying. Therefore we believe that it is not
Animal Conservation (2001) 4, 345–349 © 2001 The Zoological Society of London Printed in the United Kingdom
John D. C. Linnell1, Jon E. Swenson1,2 and Reidar Andersen1,3
1Norwegian Institute for Nature Research, Tungasletta 2, 7485 Trondheim, Norway
2Department of Biology and Nature Conservation, Agricultural University of Norway, PO Box 5014, 1432 Ås, Norway
3Zoology Department, Norwegian University of Science and Technology, 7491 Trondheim, Norway
(Received 12 September 2000; accepted 11 June 2001)
In a recent analysis Woodroffe (2000) found a positive relationship between historical patterns of
large carnivore extinction probability and human population density. However, much of the data in
this analysis came from a period when carnivore extermination was a management objective. In order
to explore the hypothesis that large carnivores can persist at high human densities when the man-
agement regime is more favourable we have repeated the analysis using up-to-date data from North
America and Europe. In North America we found that large carnivore populations have increased
after favourable legislation was introduced, despite further increases in human population density. In
Europe we found no clear relationship between present carnivore distribution and human population
density. We therefore believe that the existence of effective wildlife management structures is more
important than human density per se.
All correspondence to: John Linnell. Tel: ++ 47 73 801 442;
Fax: ++ 47 73 801 401; E-mail:
directly relevant to the discussion about how to conserve
large carnivores when we actually try.
If our hypothesis on the role of management policy is
correct, large carnivore populations should have stabi-
lized or recovered once policy objectives changed,
despite the fact that human density remained stable or
increased further. Official policy towards all predators,
including large carnivores, began changing after the
1940s, but the most dramatic changes occurred during
the early 1970s (Novak et al., 1987, and references
therein). The indiscriminate use of toxicants for carni-
vore control was banned in the United States in 1972,
and wolves (Canis lupus) and grizzly bears (Ursus arc-
tos) were placed on the endangered species list (in
the lower 48 states) in 1974 and 1975, respectively.
Similarly, bounties were removed from wolves in
the various Canadian provinces between 1949
(Saskatchewan) and 1975 (Northwest Territories). By
the mid-1970s wolves, grizzly bears and cougars (Puma
concolor) were all either protected or managed as har-
vestable game species (game or furbearer designations)
throughout Canada and the United States (Novak et al.,
1987, and references therein).
In the subsequent 25 years, there have been no fur-
ther extinctions of these three species in their range
states/provinces (Table 1). Although there have been
some local declines, these either have been due to
planned population reductions, or were reversed after the
decline was detected. In fact, most populations have
expanded. Wolves have naturally expanded from north-
eastern Minnesota (the only area where they persisted in
the lower 48 states) to recolonize central Minnesota,
upper Michigan and parts of Wisconsin and North
Dakota. In addition, northern Montana has been recolo-
nized from Alberta (Mech, 1995). In addition, the delib-
erate reintroduction of wolves into formerly occupied
habitats in Idaho and the Greater Yellowstone ecosys-
tem has been a success (Bangs et al., 1998), and a new
reintroduction is underway in the southwestern states
(Parsons, 1998). Grizzly bear populations in Alaska and
Canada remain secure, and even the five remnant pop-
ulations in the lower 48 states have generally held their
own (Servheen, Herrero & Peyton, 1999). Augmentation
of the grizzly bear population in the Cabinet–Yaak area
of Montana has been carried out, and a reintroduction
into the Selway–Bitteroot area on the Idaho–Montana
border is being planned (Servheen et al., 1999). Wildlife
managers in 15 states and provinces have reported that
their cougar populations are either stable or increasing,
including the isolated population of cougars in Florida
(reports in Paldey, 1997). This is all despite the fact that
the human population of North America has almost
quadrupled since 1900 (Woodroffe’s survey date) and
has increased by 25% since 1975 when the modern era
of conservation-orientated large carnivore management
began. Many of these states (Table 1) have human pop-
ulations well above Woodroffe’s cut-off densities (4–14
people km–2), and wolf recovery plans are being seriously
evaluated for northeastern states like New York which
has 148 people per km2 (Mladenoff & Sickley, 1998).
If large carnivore persistence is simply linked to human
population density per se, we should expect to find a sim-
ilar relationship between carnivore persistence and
human population density in an area not considered by
Woodroffe. To examine this issue we collated data on
the past distribution and present status of brown bear
(Ursus arctos), wolf and Eurasian lynx (Lynx lynx, the
ecological equivalent of a cougar) in Europe from a series
of action plans, recently published by the Council of
Europe (Boitani, 2000; Breitenmoser et al., 2000;
Swenson et al., 2000) and the IUCN (Nowell & Jackson,
1996; Servheen et al., 1999). Additional status updates
presented at a meeting of the ‘Group of Experts on Large
Carnivores to the Council of Europe’s Bern Convention’
in Oslo in June 2000 were included in some cases. We
considered countries to be former-range states if large
carnivore populations had persisted into the early 1800s
(this excludes cases like wolf extinction from Britain and
Ireland that occurred in the 1600s for example).
Extinction was defined if a given species did not occur
in a consistently reproducing status for a period of at least
some decades (Table 2). In order to test for the ability
of large carnivores to persist under modern manage-
ment regimes we repeated the analysis using present
346 J. D. C. L
Table 1. Present trends in wolf and cougar populations in North
American states in relation to present human population density.
Human population densities are for the year 2000 (US Census
Bureau). Carnivore population trends are indicated by arrow symbols
("= increasing, #= stable, $= decreasing)
State/province Human density Cougar1Wolf2
Alaska 0.4 #
Alberta 4.1 "#
Arizona 16.2 #
BC 3.9 ""
California 82.1 "
Colorado 15.1 "
Florida 108.1 #
Idaho 5.8 "
Labrador 1.4 #
Manitoba 1.7 #
Michigan 67.0 "
Minnesota 23.2 "
Montana 2.3 ""
Nevada 6.4 "
New Mexico 5.5 "
NWT30.02 #
Ontario 10.0 "
Oregon 13.3 "
Quebec 4.6 "
Saskatchewan 1.5 #
Texas 29.6 "
Utah 10.0 "
Washington 33.4 "
Wisconsin 37.3 "
Wyoming 1.9 "
Yukon 0.06 #
1Source = state-by-state survey from fifth mountain lion workshop
in 1996 (Paldey, 1997).
2Source = Hayes & Gunson, 1995; Stephenson et al., 1995; Thiel &
Ream, 1995; figures generally include up to 1992.
3Trend does not include High Arctic areas where data are lacking.
distributions of reproductive populations (including the
results of both natural recolonization and reintroduction).
There was some subjectivity associated with classify-
ing a population within a national border as simply
present or extinct, because many populations straddle
international borders and are in a dynamic state. This
was especially true for Norway, as wolves only recolo-
nized in 1998 (represented by only three packs that use
Norwegian territory exclusively in 2000) and no repro-
ducing female bears exclusively use Norwegian territory
(Swenson, Sandegren & Söderberg, 1998). As Norway
has by far the lowest human population density in main-
land Europe, the classification of its wolf and bear pop-
ulations can have a dramatic effect on the analysis.
Therefore, we carried out separate analyses where these
populations were considered as either present or extinct,
respectively. Human population densities were taken
from the estimated present densities (year 2000) by the
United States Census Bureau. Although some countries’
populations may have grown at slightly different rates
during the last two centuries, we believe that the rela-
tive rankings should be unchanged, and present human
density is directly relevant to the analysis for persistence
at the present time.
The only species showing a significant relationship
between human population density and historical extinc-
tion since the early 1800s was the Eurasian lynx (Tables
2 and 3). This probably reflects the greater vulnerabil-
ity of lynx to human influences on their ungulate prey
base rather than disproportionate human persecution.
Lynx are strictly carnivorous and therefore cannot sur-
vive in the absence of prey species; wolves and bears
are better able to survive on garbage and plants, respec-
tively. With regard to present coexistence with humans,
lynx showed no relationship to human density, owing to
their successful reintroduction and recolonization in
many countries in central Europe. Although the present
status of both wolves and bears appeared to show a rela-
tionship with human density, this was due to the influ-
ence of Norway as an outlying data point (Table 3). If
Norwegian wolf and bear populations were included in
the analysis as functionally extinct, then there was no
significant relationship between human density and car-
nivore presence.
There is no doubt that Europe’s large carnivores have
been greatly reduced owing to human activities during
past centuries. Direct persecution, destruction of their
prey base and deforestation have all led to dramatic
reductions in distribution and numbers (Boitani, 1995;
Breitenmoser, 1998). Large carnivores were driven to
extinction in many countries, often early in historic or
even prehistoric times. However, the results from our
analysis show that, in general, there are few consistent
relationships between human population density and
large carnivore extinction in Europe. In addition, the crit-
ical densities are far higher than those found by
Woodroffe for North American large carnivores. Why is
We believe that it is due to two factors. First, it is
important to remember that Europeans have shared their
continent with large carnivores for around 30,000 years.
347Large carnivores, human density and management policy
Table 2. Present trends in large carnivore populations in European
countries in relation to present human population density. P? = repro-
ducing population present but trend is uncertain; T = only transient
individuals present; E = extinct; NP = never present. Human popu-
lation densities are for the year 2000 (US Census Bureau). Carnivore
population trends are indicated by arrow symbols ("= increasing,
#= stable, $= decreasing)
Country Human Lynx1Bear2Wolf3
density (km–2)
Albania 121.40 ?P? #"
Austria 96.97 T "E
Bosnia 75.02 ?P? ?P? $
Bulgaria 70.30 E $#
Croatia 75.73 ## "
Czech Republic 130.30 #T "
Estonia 31.73 ## #
Finland 15.33 """
France 107.98 "#"
Germany 232.12 "E T
Greece 80.35 ?P? $#
Hungary 108.99 T E #T#
Italy 191.33 T #"
Latvia 37.76 ###
Lithuania 55.54 #T "
Macedonia (FYROM) 79.37 ?P? #"
Moldova 131.48 E E #
Norway 13.82 #" "
Poland 123.59 ## "
Portugal 109.12 NP E #
Romania 94.36 #($)4"
Slovakia 110.29 $"#
Slovenia 95.21 ## "
Spain 79.24 NP $"
Sweden 19.73 """
Switzerland 175.89 #E #T"
Ukraine 81.42 ?P? $#
Yugoslavia 104.36 ?P? ?P? ?P?
1Source = Breitenmoser et al., 2000; figures are for 1998.
2Source = Swenson et al., 2000; figures are for 1998.
3Source = Boitani, 2000; figures are for 1998.
4Reducing the brown bear population is currently a management goal
in Romania.
Table 3. Logistic regression analysis of large carnivore extinction in
European countries with respect to human population density. ‘Past
extinction’ includes countries where the species became extinct for a
period of at least several decades after 1800. ‘Present status’ is based
on the data in Table 2, and includes the results of population persis-
tence, recolonization and reintroduction. The later analysis has been
presented with and without Norway, as the country’s low population
density gives it a strong effect on the analysis, and the status of wolves
and bears is undergoing rapid change
N c2PMean human Mean human
density at density at
extinction persistence
Past extinction 26 9.0 0.003
Present status 26 0.2 0.677 94.0 ± 32.8 94.7 ± 55.1
Brown bear
Past extinction 28 1.1 0.3
Present status 28 4.8 0.03 135.5 ± 61.2 83.4 ± 42.4
Present status 28 0.4 0.52
(Norway set as extinct)
Past extinction 28 0.01 0.904
Present status 28 6.7 0.01 168.3 ± 67.9 85.8 ± 41.7
Present status 28 0.08 0.773
(Norway set as extinct)
This long-term overlap has led to a relatively high degree
of coexistence, for example with wolves exploiting
anthropomorphic food sources when wild prey are
absent (Vos, 2000), and with shepherds adopting effec-
tive methods of guarding their livestock (Coppinger &
Schneider, 1995). The second factor is clearly one of tra-
dition, which is expressed through management regula-
tion (Boitani, 1995). Royal decrees to regulate hunting
of bears date back to the 1600s in some cases, and most
countries were managing bears as game species by the
early- to mid-1900s. There is no doubt that the concept
of hunting large carnivores as game species is far older
in Europe than in North America and contributed greatly
to their persistence. In addition, despite the very high
human densities in Europe today (Table 2), the historic
declines in large carnivore numbers appear to have been
reversed with only a few exceptions. Large carnivore
population trends in most countries are stable or increas-
ing, and intensive conservation efforts are underway to
reverse the slow declines occurring in a few areas.
One example that clearly shows the importance of
management policy is that of brown bears in Scandinavia
(Swenson et al., 1995). Both countries have low human
population densities (14 km–2 in Norway, 20 km–2 in
Sweden). Bounties on bears were introduced early (1733
in Norway, 1647 in Sweden). As a result, bear popula-
tions were rapidly reduced in both countries. However,
management policy diverged in the late 1800s. Bounties
were removed in Sweden in 1893, and increasing levels
of protection were phased in from 1909. This led to such
an increase that managed hunting could begin in 1943.
Today there is a population of about 1000 bears, that is
still increasing despite providing an annual harvest of 50
bears (Sandegren & Swenson, 1997). In contrast, despite
phasing out the state bounty in 1930 in Norway, unreg-
ulated killing was still permitted up until 1972, when
bears were finally given protection. By this time they
were functionally extinct (Swenson et al., 1995, 1998).
Recolonization from Sweden, Russia and Finland is
presently allowing a slow recovery of the Norwegian
In conclusion, the data support our hypothesis that pat-
terns of large carnivore extinction and persistence in
Europe and North America are more adequately
explained by management policy and its enforcement
than by human population density. We therefore predict
that human density and carnivore density interact dif-
ferently in two phases of the development of wildlife
management structures. First, where there is no effec-
tive regulation of human behaviour, weapons (and poi-
son) are available, and a rapid period of human
expansion occurs into areas where resource exploitation
is not controlled, large carnivore extinction should be
related positively to human density (the ‘frontier’ phase).
This is mediated by a combination of habitat change,
destruction of prey base and direct persecution. This sit-
uation broadly corresponds to North America up until
the mid-1900s, and much of the developing world today.
Woodroffe’s (2000) analysis of North American data has
clearly shown how large carnivore extermination can be
achieved (if desired) even at very low human densities.
Second, where there is effective regulation of human
behaviour and established human populations in areas
where resource exploitation is regulated, there should be
no strong correlation between human density and carni-
vore extinction (the ‘stabilised’ or ‘wildlife manage-
ment’ phase). This corresponds to most of Europe and
North America today. In this phase, large carnivore
recovery into remaining habitat can occur, through either
natural recolonization or planned reintroduction. The
European experience shows how brown bears, lynx and
wolves can survive at high human densities.
The important implication of our results is that large
carnivore conservation requires the rapid establishment
of effective wildlife management and enforcement struc-
tures that either make protection effective or regulate
harvest of both large carnivores and their prey at sus-
tainable levels. Of course, achieving this in the devel-
oping world requires a whole range of measures, like
slowing human population growth, and fostering sus-
tainable socio-economic development. The point is that
large carnivore conservation is possible at high human
density, and that even wilderness protection is no guar-
antee of persistence (Woodroffe & Ginsberg, 1998).
European and North American experience clearly shows
that large carnivores and their prey can persist within
many heavily modified habitats (though not all) at high
human densities and even where both predators and their
prey are being harvested. In the face of the pressures on
wilderness areas today, this is extremely good news for
large carnivores (Linnell, Swenson & Andersen, 2000).
Implementation of such a policy requires an urgent
building of bridges between the academic field of con-
servation biology and the hands-on field of wildlife man-
We would like to thank Hans C. Pedersen, Henrik
Brøseth, John Odden and Erling J. Solberg for con-
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349Large carnivores, human density and management policy
... A popular example is the case of large carnivore species that have undergone substantial range contractions due to intensive persecution by humans. While many species continue to struggle, some have in recent decades successfully recolonized part of their historic range, particularly in Western Europe and North America (Linnell et al. 2001, Zedrosser et al. 2011, Chapron et al. 2014, Ripple et al. 2014, Ingeman et al. 2022. Limited understanding of factors shaping the spatial configuration of carnivore populations poses a challenge to science and management, and the current knowledge gaps may hinder predictions of future responses in the face of increasing human pressure. ...
... In Scandinavia, population and landscape-level determinants of wolverine distribution and density are poorly known. Historical (Landa et al. 2000) and current (Chapron et al. 2014) range maps suggest that recolonization in this anthropogenic landscape has been facilitated by favorable legislation and improved cultural acceptance (Linnell et al. 2001, Flagstad et al. 2004, Aronsson and Persson 2017. However, there is evidence that biophysical constraints, such as climate, habitat, and terrain, have played a greater role in shaping the current distribution of the wolverine at the continental scale (Cretois et al. 2021). ...
... historical and current core) or the species was pushed into the alpine refuge areas during the peak of the persecution is not fully understood (Flagstad et al. 2004, Kerley et al. 2012, Zigouris et al. 2013. Nonetheless, wolverine recolonization in Scandinavia matches the general pattern of return of other large carnivore species in Western Europe and North America (Linnell et al. 2001, Chapron et al. 2014. Successful recovery of these species is partially attributed to changing public attitudes towards large carnivores and effective law enforcement which, in turn, have lowered the risk of direct killing by humans (Zedrosser et al. 2011, Ingeman et al. 2022. ...
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After centuries of intense persecution, several large carnivore species in Europe and North America have experienced a rebound. Today's spatial configuration of large carnivore populations has likely arisen from the interplay between their ecological traits and current environmental conditions, but also from their history of persecution and protection. Yet, due to the challenge of studying population‐level phenomena, we are rarely able to disentangle and quantify the influence of past and present factors driving the distribution and density of these controversial species. Using spatial capture‐recapture models and a data set of 742 genetically identified wolverines Gulo gulo collected over ½ million km² across their entire range in Norway and Sweden, we identify landscape‐level factors explaining the current population density of wolverines in the Scandinavian Peninsula. Distance from the relict range along the Swedish–Norwegian border, where the wolverine population survived a long history of persecution, remains a key determinant of wolverine density today. However, regional differences in management and environmental conditions also played an important role in shaping spatial patterns in present‐day wolverine density. Specifically, we found evidence of slower recolonization in areas that had set lower wolverine population goals in terms of the desired number of annual reproductions. Management of transboundary large carnivore populations at biologically relevant scales may be inhibited by administrative fragmentation. Yet, as our study shows, population‐level monitoring is an achievable prerequisite for a comprehensive understanding of the distribution and density of large carnivores across an increasingly anthropogenic landscape.
... Some investigators have suggested that mountain lions avoid residential development and human infrastructure, like roads [18][19][20]. However, like other large carnivores in North America and Europe [21,22], habitat restoration and conservation actions have facilitated mountain lion population persistence and even recoveries of their previously occupied range in increasingly human-dominated landscapes [15,23]. This inevitably leads to increases in conflict with their new neighbours, humans [19,24]. ...
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Artificial light at night (ALAN) is increasing in extent and intensity across the globe. It has been shown to interfere with animal sensory systems, orientation and distribution, with the potential to cause significant ecological impacts. We analysed the locations of 102 mountain lions ( Puma concolor ) in a light-polluted region in California. We modelled their distribution relative to environmental and human-disturbance variables, including upward radiance (nearby lights), zenith brightness (sky glow) and natural illumination from moonlight. We found that mountain lion probability of presence was highly related to upward radiance, that is, related to lights within approximately 500 m. Despite a general pattern of avoidance of locations with high upward radiance, there were large differences in degree of avoidance among individuals. The amount of light from artificial sky glow was not influential when included together with upward radiance in the models, and illumination from moonlight was not influential at all. Our results suggest that changes in visibility associated with lunar cycles and sky glow are less important for mountain lions in their selection of light landscapes than avoiding potential interactions with humans represented by the presence of nearby lights on the ground. This article is part of the theme issue ‘Light pollution in complex ecological systems’.
... Instances of HPC may originate where predators prey on livestock (Wang & Macdonald, 2006;, utilise resources of recreational value (Pederson et al., 1999;Skonhoft, 2006), damage human property (Gunther et al., 2004), pose a threat to the safety of humans (Loe & Roskaft, 2004;Thavarajah, 2008), or compete with other species of conservation or economic value (Engeman, Shwiff, Constantin, Stahl & Smith, 2002). In response, humans employ a range of management strategies to moderate the costs that they incur from HPC. W HILE many predation management strategies have shown some success in reducing livestock losses (Linnell, Swenson & Andersen, 2001), negative consequences of predation management have also been demonstrated, including: (1) the extinction or near extinction of predators in certain areas because of eradication programmes (Woodroffe & Ginsberg, 1999;Bauer & Van der Merwe, 2004;Chapter 2); (2) the alteration of ecosystems and apparent increases in the numbers of some primary consumers and/or meso-predators where predators were excluded or eradicated (Estes, 1996;Chapter 8); (3) threats to populations of non-target species because of non-specific management techniques (Glen, Gentle & Dickman, 2007; also see "Predation management methods"); (4) counterproductive predation management approaches, with more livestock losses occurring after their implementation (Allen, 2014;Treves, Krofel & McManus, 2016); and (5) the straining of relationships between livestock producers, different sectors of society and policy makers (Madden, 2004;Thompson, Aslin, Ecker, Please & Tresrail, 2013;Chapter 4). ...
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This assessment provides a policy relevant synthesis on the topic of livestock predation and its management in South Africa, as well as recommendations for future research. See also
... leopards are timid species that live solitary. Their numbers are in rapid decline due to several mortality factors stemming from human activities such as industrialization, forest fires, tourism, and poaching (Madden, 2008;Linnell et al., 2001;Sarı, 2018;Zak and Riley, 2016;Ünal et al., 2020). ...
... Assessing habitat suitability appears to be exceptionally important for the carnivore conservation, mainly because the human attitude towards them has dramatically changed worldwide, where, in the last decades, persecution and hunting has been replaced with various forms of protection (Linnell, Swenson, & Andersen, 2001). This change has contributed considerably to the recently observed increase in numbers and the range of some species of carnivores in Europe, resulting from both, reintroductions and natural expansions (Chapron et al., 2014). ...
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Large European carnivores are generally considered forest animals. However, there are a number of interacting factors that may have different impact on the availability and suitability of habitat for individual species. Felids, because of their stalking hunting mode, are habitat specialists requiring a heterogeneous environment, making them specifically vulnerable to habitat disturbance. The Eurasian lynx ( Lynx lynx ), despite protection in many European countries, has a surprisingly limited range. To explain environmental factors that affect its distribution, we undertook habitat selection and habitat suitability analyses at the macrohabitat and microhabitat scales, based on lynx occurrence and environmental data in Poland. Since the species occurs in two populations, one of which inhabits lowland and the other mountainous area, we modelled habitat suitability separately in both areas and then extrapolated it for the whole country scale. The lynx selected forests with medium undergrowth density in the lowlands and highly rugged terrain in the mountain areas—a proxy of stalking cover. Habitat suitability modelling performed at the macrohabitat scale identified around 110 000 km ² of habitat available from which 55 700 km ² was classified as high quality including large tracts of forests in western Poland that are beyond the natural range of the lynx. However, the microhabitat model built by including stalking cover variables, decreased high‐quality habitats to only 33% of the area designated at the macrohabitat scale. This model is largely consistent with the current distribution of lynx in Poland. This suggests that the simplified internal structure of forests (lacking understory cover) may act as a hindrance to increasing the distribution of lynx populations and helps to explain its limited range in the Central European lowlands. This research suggests that the microhabitat structure may play the crucial role in the effective conservation of the Eurasian lynx.
... Conflict with recolonizing grey wolf (Canis lupus) populations is becoming common ( Lozano et al. 2019 ), typically including human safety and livelihood issues, such as livestock depredation and associated impacts on farmers. This conflict is being exacerbated by the loss of husbandry practices that incorporated damage prevention measures after the long absence of large carnivores and conservation legislation, which have led to the recovery of wolves whose ranges overlap with human activities ( Linnell et al. 2001 ; nonpredator species ( Treves and Naughton-Treves 2005 ;Gehring et al. 2010a ;Lieb et al. 2021 ). ...
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The efficacy of livestock guarding dogs (LGDs; Canis familiaris) on modern ranches in the dense multiuse landscape of rural northern Israel is controversial. Minimal time is spent by the ranchers with the herd and LGDs, and the LGDs are known to wander to nearby army bases, homesteads, villages, and other facilities. Thirteen Akbash and six mixed-breed LGDs guarding cattle in a paddock were observed through direct observations and tracking with Global Positioning System collars. Predator presence and interaction with LGDs were recorded using telemetry and trail cameras. In addition, 10 local ranchers were interviewed to assess the effects of management and LGD use on depredation. We expected Akbash LGDs to exhibit behavioral traits consistent with depredation mitigation and that differing ranch-LGD management methods would impact depredation levels. At the study ranch, depredations were at a minimum despite the presence of three wolf packs (Canis lupus) and jackals (Canis aureus) in the vicinity of the observed ranch. The Akbash LGDs spatially displaced wolves and temporally displaced jackals, but they also regularly roamed away from the paddock and returned. In addition, Akbash LGDs were more likely to follow the herd than mixed-breed LGDs; the total number of LGDs in the paddock increased with the number of newborn calves; and LGD intra-aggression increased with the number of LGDs present in the paddock. In the survey, we found little relationship between ranch management type and depredation outcomes. In particular, the use of protective enclosures by some ranches did not mitigate depredation compared with ranches without enclosures. In modern multiuse landscapes, Akbash LGDs show potential for being an important component of depredation mitigation, but their relative contribution needs to be studied further. In addition, the use of protective enclosures, which are known to have negative ecological impacts, should be reconsidered. Several improvements to LGD management are suggested.
Large carnivores strongly shape ecological interactions within their respective ecosystems, but experience significant conflicts with humans across their range due to their specific ecological resource requirements. The Tiger (Panthera tigris) typifies the challenges faced by large carnivore species globally. India retains the majority of the global Tiger population with a substantial number occurring outside protected areas where they are prone to conflict through livestock predation and injury or death to people and Tigers. Tiger food habits was investigated across the Indian part of the Terai-Arc Landscape (TAL), a globally important Tiger conservation landscape, to understand Tiger prey selection patterns and hotspots of livestock predation-related conflict. 510 genetically confirmed Tiger feces were collected across the landscape and 10 wild ungulates and livestock as prey species were identified. Large-bodied species (Sambar, Swamp Deer, Nilgai, Chital, Wild Pig, and livestock) comprised ~94% of the diet, with Sambar, Chital, and livestock having the highest relative proportions. Habitat-specific (Shivalik-Bhabar and Terai) analyses indicate that prey selection is driven by prey abundance and body weight but not determined by protection status (protected areas vs non-protected areas). Results also suggest that PAs and non-PAs in the Terai region were more prone to livestock predation-related conflict. Careful management interventions with community involvement should be utilized to reduce such threats. In this study, we suggest long-term conservation plans including prey abundance estimation outside PAs, reduction of grazing pressures, and detailed records of Tiger mortalities with causal investigations to ensure future conflict-free Tiger persistence across TAL.
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1. Wildlife populations live in increasingly human-altered landscapes. Either because of their intrinsic values or due to instrumental values to humans, wildlife populations are monitored to inform about their current status and population trends and to forecast their future status in response to possible changes in their environment. Monitoring wildlife across spatial units and over time is a first step towards adaptive and evidence-based management. 2. This PhD dissertation consists of four articles that are centered on developing new methods, enhancing concepts, and showcasing applications of novel analytical approaches for quantifying landscape-level wildlife population density using noninvasive monitoring data. At the core of this PhD dissertation lie spatially explicit analytical models, namely spatial capture-recapture (SCR), with the ability to yield scale-transcending estimates of population parameters, while accounting for imperfect detection. This PhD dissertation is motivated by applied questions raised during noninvasive genetic monitoring of large carnivores in the Scandinavian Peninsula. However, the methodology and findings have broader implications. 3. The first two articles focus on understanding and mitigating the consequences of spatially variable and autocorrelated detection probability when analyzing wildlife monitoring data. Detection probability – the probability of detecting an individual from the target population, can vary across the study area, because of, for example, certain landscape characteristics or the specifics of the sampling design. Spatial autocorrelation in detection probability occurs when detectability is more similar among neighboring than distant sampling locations or devices. Both articles I and II use simulations to create and test many scenarios that may occur during real-life sampling of wildlife in monitoring studies. Article I evaluates the consequences of not accounting for spatial variation in detectability when analyzing monitoring data with SCR, with a specific focus on the impact on estimates of population size. This study shows that a misspecified SCR model performs reasonably well in many situations, from low to even intermediate levels of spatial variation in detectability. However, Article I identifies problematic cases of highly spatially variable and autocorrelated detection, which can lead to pronounced negative bias in population size estimates. Some of these extreme scenarios are expected in the large-scale monitoring of large carnivores in Scandinavia, which led to a follow-up study in the next chapter of this PhD. 4. Article II describes and tests three novel modeling approaches to account for spatially variable and autocorrelated detection probability in SCR with random effects. This study extends SCR with generalized linear mixed models (GLMMs) and compares the performance of the SCR-GLMMs that do and do not specifically account for spatial autocorrelation in detection probability. Article II then applies the new modeling approaches to Scandinavian brown bear Ursus arctos monitoring data from central Sweden, where the majority of the DNA data was collected opportunistically by volunteers and no reliable measure of sampling effort was available to infer spatially variable detectability. This empirical case study demonstrates the application of the proposed modeling approaches and suggests considerable spatial heterogeneity in the detection of bears, where detectability decreases in an east-to-west direction towards the Swedish-Norwegian border. Further, Article II discusses solutions to identify potential sampling gaps, where variation in the effort is not fully known and highlights computation trade-offs in using such novel SCR analyses in wildlife monitoring studies. 5. The next two articles demonstrate empirical applications of quantifying variation in wildlife population density and its determinants at the population level. Our current understanding of wildlife space use and habitat selection is dominated by geographically limited studies that often make inferences from a few instrumented individuals. Both articles III and IV use noninvasive genetic monitoring data of the wolverine Gulo gulo across the species’ entire range in the Scandinavian Peninsula and assess sex-specific responses of the wolverine density to a suit of historical and present-day environmental covariates. Both these articles predict the Scandinavian wolverine density distribution and provide estimates of population size. Article III, as a prelude to the next chapter, identifies the factors influencing the current density distribution of the wolverine, with a focus on the role of the relict range along the Swedish-Norwegian border, where the wolverine survived intense human persecution by early 1970s. Article III reveals that distance from this transboundary alpine region is still one of the most important determinants of wolverine density and the highest female and male wolverine densities are expected closer to the relict range. However, current management conditions to limit wolverine expansion, especially in southern Norway, interact with distance from the relict range, and together with other topographic, climatic, and prey-related factors, have shaped the current density distribution of the wolverine in Scandinavia. This study is the first to look into the density determinants of the Scandinavian wolverine population across its entire geographic range. 6. Article IV builds on the findings from Article III and quantifies the dynamics of density determinants of the Scandinavian wolverine over a nine-year monitoring period. This study quantified the change in the impact of the environmental covariates over the past decade, as the wolverine has successfully expanded from the alpine relict range into the boreal forest. Article IV uses recently developed open-population SCR models that provide not only estimates of annual density and its determinants, but also estimates of the demographic parameters (i.e., recruitment and survival) needed to predict changes in the population dynamics. This study reveals that, on the one hand, whereas the role of the relict range is still important for determining the wolverine’s density distribution, its significance is diminishing over time. On the other hand, forest is appearing more and more as a significant predictor of today’s wolverine density. Article IV tracks temporal trends in the main determinants of male and female wolverine densities and it discusses the results in relation to the population recovery of the wolverine in Scandinavia in the presence of ongoing human pressure.
Records of bountied brown bears Ursus arctos in Norway and Sweden were analysed to estimate population size in the mid-1800's, and changes in population size and distribution in relation to the bear management policies of both countries. In the mid-1800's about 65% of the bears in Scandinavia were in Norway (perhaps 3,100 in Norway and 1,650 in Sweden). Both countries tried to eliminate the bear in the 1800's; Sweden was more effective. By the turn of the century, the numbers of bears were low in both countries. The lowest population level in the population remnants that have subsequently survived occurred around 1930 and was estimated at 130 bears. Sweden's policy was changed at the turn of the century to save the bear from extinction. This policy was successful, and the population is now large and expanding. Norway did not change its policy and bears were virtually eliminated by 1920-30. Since 1975, bear observations increased in Norway. This coincided temporally with an abrupt increase in the Swedish bear population, and bears reappeared sooner in areas closer to the remnant Swedish populations. Both conditions support our conclusion that the bear was virtually exterminated in Norway and suggest that bears observed now are primarily immigrants from Sweden, except for far northern Norway, which was recolonised from Russia and Finland. Today, we estimate that the Scandinavian bear population numbers about 700, with about 2% in Norway (on average about 14 in Norway, 650-700 in Sweden). This is a drastic reduction in the estimate of bears in Norway, compared with earlier studies. The trends in bear numbers responded to the policies in effect. The most effective measures used in Scandinavia to conserve bears were those that reduced or eliminated the economic incentive for people to kill them. Our analysis also suggests that population estimates based on reports from observations made by the general public can be greatly inflated.
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.