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REVIEW: The management of wild large herbivores to meet economic, conservation and environmental objectives

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Abstract

Summary • Wild large herbivores provide goods and income to rural communities, have major impacts on land use and habitats of conservation importance and, in some cases, face local or global extinction. As a result, substantial effort is applied to their management across the globe. To be effective, however, management has to be science-based. We reviewed recent fundamental and applied studies of large herbivores with particular emphasis on the relationship between the spatial and temporal scales of ecosystem response, management decision and implementation. • Long-term population dynamics research has revealed fundamental differences in how sex/age classes are affected by changes in density and weather. Consequently, management must be tailored to the age and sex structure of the population, rather than to simple population counts. • Herbivory by large ungulates shapes the structure, diversity and functioning of most terrestrial ecosystems. Recent research has shown that fundamental herbivore/vegetation interactions driving landscape change are localized, often at scales of a few metres. For example, sheep and deer will selectively browse heather Calluna vulgaris at the edge of preferred grass patches in heather moorland. As heather is vulnerable to heavy defoliation, in the long term this can lead to loss of heather cover despite the average utilization rate of heather in a management area being low. Therefore, while herbivore population management requires a large-scale approach, management of herbivore impacts on vegetation may require a much more flexible and site-specific approach. • Localized impacts on vegetation have cascading effects on biodiversity, because changes in vegetation structure and composition, induced by large herbivores affect habitat suitability for many other species. As such, grazing should be considered as a tool for broader biodiversity management requiring a more sophisticated approach than just, for example, eliminating grazing from conservation areas through the use of exclosures. • Synthesis and applications. The management of wild large herbivores must consider different spatial scales, from small patches of vegetation to boundaries of an animal population. It also requires long-term planning based on a deep understanding of how population processes, such a birth rate, death rate and age structure, are affected by changes in land use and climate and how these affect localized herbivore impacts. Because wild herbivores do not observe administrative or political boundaries, adjusting their management to socio-political realities can present a challenge. Many developing countries have established co-operative management groups that allow all interested parties to be involved in the development of management plans; developed countries have a lot to learn from the developing world's example. Journal of Applied Ecology (2004) 41, 1021 –1031
Journal of Applied
Ecology
2004
41
, 1021– 1031
© 2004 British
Ecological Society
Blackwell Publishing, Ltd.Oxford, UKJPEJournal of Applied Ecology0021-8901British Ecological Society, 200412 20044161021
Review ArticleManagement of wild large herbivoresI. J. Gordon, A. J. Hester & M. Festa-Bianchet
REVIEW
The management of wild large herbivores to meet
economic, conservation and environmental objectives
IAIN J. GORDON,*† ALISON J. HESTER* and MARC O FESTA-BIANCHET‡
*
Macaulay Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK;
CSIRO-Davies Laboratory, PMB PO Aitkenvale,
Queensland 4814, Australia; and
Department of Biology, University of Sherbrooke, Sherbrooke, Canada PQ J1K 2R1
Summary
1.
Wild large herbivores provide goods and income to rural communities, have major
impacts on land use and habitats of conservation importance and, in some cases, face
local or global extinction. As a result, substantial effort is applied to their management
across the globe. To be effective, however, management has to be science-based. We
reviewed recent fundamental and applied studies of large herbivores with particular
emphasis on the relationship between the spatial and temporal scales of ecosystem
response, management decision and implementation.
2.
Long-term population dynamics research has revealed fundamental differences
in how sex/age classes are affected by changes in density and weather. Consequently,
management must be tailored to the age and sex structure of the population, rather
than to simple population counts.
3.
Herbivory by large ungulates shapes the structure, diversity and functioning of most
terrestrial ecosystems. Recent research has shown that fundamental herbivore/vegeta-
tion interactions driving landscape change are localized, often at scales of a few metres.
For example, sheep and deer will selectively browse heather
Calluna vulgaris
at the edge
of preferred grass patches in heather moorland. As heather is vulnerable to heavy
defoliation, in the long term this can lead to loss of heather cover despite the average
utilization rate of heather in a management area being low. Therefore, while herbivore
population management requires a large-scale approach, management of herbivore
impacts on vegetation may require a much more flexible and site-specific approach.
4.
Localized impacts on vegetation have cascading effects on biodiversity, because
changes in vegetation structure and composition, induced by large herbivores affect habitat
suitability for many other species. As such, grazing should be considered as a tool for
broader biodiversity management requiring a more sophisticated approach than just,
for example, eliminating grazing from conservation areas through the use of exclosures.
5.
Synthesis and applications
. The management of wild large herbivores must consider
different spatial scales, from small patches of vegetation to boundaries of an animal
population. It also requires long-term planning based on a deep understanding of how
population processes, such a birth rate, death rate and age structure, are affected by
changes in land use and climate and how these affect localized herbivore impacts.
Because wild herbivores do not observe administrative or political boundaries, adjusting
their management to socio-political realities can present a challenge. Many developing
countries have established co-operative management groups that allow all interested
parties to be involved in the development of management plans; developed countries
have a lot to learn from the developing world’s example.
Key-words
:bighorn sheep, conservation, habitat management, impala, population
dynamics, red deer, saiga antelope, ungulates
Journal of Applied Ecology
(2004)
41
, 1021–1031
Correspondence: I. J. Gordon, CSIRO-Davies Laboratory, PMB PO Aitkenvale, Qld 4814, Australia (fax + 61 74753 8600; e-mail
iain.gordon@csiro.au).
1022
I. J. Gordon,
A. J. Hester &
M. Festa-Bianchet
© 2004 British
Ecological Society,
Journal of Applied
Ecology
,
41
,
1021–1031
Introduction
In many parts of the world, populations of wild large
herbivores provide a substantial resource supplying
local and regional communities with goods and eco-
nomic income (Conover 1997; Barnes, Schier & van
Rooy 1999; Loibooki
et al
. 2002; Ogutu 2002). They
also have a major impact on land use and habitats of
conservation importance (Hobbs 1996; Kirby 2001).
Some species are the targets of policies to conserve
dwindling populations (Stanley Price 1989; IUCN
2002) while others are increasing in number and need
to be controlled, for example deer in UK woodlands
(Putman & Moore 1998). In this review, we highlight
how recent ecological research has investigated the
relationships between large herbivores and their re-
sources, yielding insights into the dynamics of the
herbivores and the vegetation upon which they subsist.
We emphasize the role of spatial and temporal variation
in herbivore and vegetation abundance, giving examples
of how this information could provide guidance to
those responsible for devising and implementing the
conservation, harvesting and culling of large herbivores
across the globe.
Historically, the vast populations of large herbivores
that roamed the plains of Africa, the steppes of Asia
and the prairies of America appeared to offer a vast,
bountiful resource for humans to exploit (Roosevelt
1910). However, overexploitation, predation, disease
and changes in climate and land use have reduced many
large herbivore species to levels at which they now need
to be actively conserved (Beard 1988; Teer
et al
. 1996;
Danz 1997). On the other hand, in the developed world
some species have benefited from climate and land-use
changes, reduced human off-take and the removal of
predators, and now require management to ensure that
their numbers do not affect other land-use objectives,
including agriculture, forestry and habitat requirements
for other species (Gill 1990; McShea, Underwood &
Rappole 1997).
For well over half a century, one of the prime justifica-
tions of applied ecological research has been to provide
objective information for ecosystem managers who
wish to meet environmental and economic objectives
(Elton 1924; Sheail 1985, 1987). For example, since the
mid-1950s information derived from large game counts
has been used to set harvest quotas for many ungulates
in Africa, North America and Europe, either for sport
hunting (Caughley & Sinclair 1994) or to reduce
impacts on, for example, commercial timber stocks
(Putman & Moore 1998; Terry, Mclellan & Watts
2000). While this long history of linking ecological
research with management advice has been valuable to
both parties (Sheail 1987; Sutherland 2000), ecologists
are now expected to link their science more closely with
the needs of the public if scarce public funds are to be
channelled into research rather than competing uses
such as education, health, transport and the military
(Dale
et al
. 2000). Furthermore, natural resource
managers are seeking increasingly sophisticated advice,
for example the escalating costs of both surveying
and culling large herbivores means that more precise
information is needed for managers regarding how
many animals to cull or which sections of the population
(e.g. age/sex classes and geographical location) are
damaging natural resources (Gill 1992; Georgiadis,
Hack & Turpin 2003).
Recently, both the research and management com-
munities have been questioned about the extent to
which advances in the understanding of the ecology of
natural resources have been used to guide management
(Stinchcombe
et al
. 2002). In an effort to address this
issue we present recent developments in large herbivore
ecology that are most likely to guide the development
of management planning to meet economic, conservation
and environmental objectives. For these developments
to be taken up by managers, ecologists must collaborate
with researchers in the humanities to develop method-
ologies by which ecological science-based management
is adopted by managers and policy makers.
Why does large herbivore management matter?
First, large herbivores have high economic value; they
are often an important source of revenue through sport
hunting (Williamson & Doster 1981; van der Waal &
Dekker 2000; Leader-Williams, Smith & Walpole
2001) and ecotourism (Barnes, Schier & van Rooy
1999; Ogutu 2002). They can also be major pests to
agriculture, forestry and conservation areas, and they
may present serious traffic hazards (Ratcliffe 1987;
McShea, Underwood & Rappole 1997; Ramsay 1997;
Malo, Suárez & Díez 2004). For example, at present
a trophy value of approximately US$10500 is placed
on a male elephant
Loxodonta africana
in Zimbabwe
(http://safariconsultants.com/zornframespage.htm), with
much of this revenue returning to natural resource manage-
ment organizations and local communities (Murphree
2001). In Scotland, the cull of more than 70000 red
deer
Cervus elaphus
per year generates more than £5
million per annum, and 300 permanent and 450 part-
time jobs for the rural economy (Reynolds & Staines
1997). The latter value is likely to be substantially
higher when ancillary activities such as accommodation,
transport, craft and food and drink purchases are taken
into account (K. Thomson, W. Slea & D. Macmillan,
personal communication). As long ago as 1975, deer
hunters in the USA were estimated to spend more than
$1 billion annually on pursuing their sport (Williamson
& Doster 1981) and this is likely to be substantially
higher today.
Secondly, some large mammalian herbivores are
priorities for conservation because their populations are
critically low as a consequence of habitat loss, persecution
and overhunting. Of the approximately 175 species of
ungulates in the world, 84 are listed as critically endan-
gered, endangered or vulnerable in the 2002
Red Data
Book
of the International Union for the Conservation
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Management of
wild large
herbivores
© 2004 British
Ecological Society,
Journal of Applied
Ecology
,
41
,
1021–1031
of Nature (IUCN) (IUCN 2002; http://www.redlist.org/).
Large herbivores are often used as flagship species for
conservation management planning because of their
high public profile (Stanley Price 1989; Bowen-Jones &
Entwistle 2002) and because they are keystone species
in many ecosystems (Danell
et al
. in press).
Finally, across the globe, large areas are grazed by
wild herbivores that drive the structure, composition
and functioning of these ecosystems (Miles 1985; Mar-
tin 1993; Thompson, Hester & Usher 1995; Pickup,
Bastin & Chewings 1998; Wallis de Vries, Bakker & van
Wieren 1998). High densities of large herbivores can
impact upon the agricultural, conservation and envi-
ronmental value of the landscape (McShea, Under-
wood & Rappole 1997).
Successful large herbivore management, be it driven
by economic goals or by the desire to conserve and
expand specific habitats or species, requires a clear
understanding of the processes involved in plant–
herbivore interactions and their consequences for the
dynamics of both plants and herbivores; in this context
applied ecological research is crucial. The following
sections address key areas of importance to managers
to demonstrate the value of ecological research in
understanding the population dynamics of large
herbivores and their impacts on natural resources.
Density-dependent and density-independent
drivers of large herbivore population dynamics
An understanding of what factors cause animal popula-
tions to increase, decrease or remain stable is fundamental
to the provision of advice on how to manage them.
While it is advocated that species restoration and con-
servation plans should be based upon sound studies of
the species’ population ecology and habitat requirements
(Bodmer, Fang & Ibanez 1988; Stanley Price 1989),
there are still many cases where the fundamental data
required to inform the process are lacking (Stinchcombe
et al
. 2002) or where developments in theoretical ecology
are not incorporated into management plans.
Long-term ecological studies of population dynamics
in large mammalian herbivores provide a detailed under-
standing of the effects of intrinsic and extrinsic factors
in determining population size and composition
(Saether 1997; Gaillard, Festa-Bianchet & Yoccoz 1998;
Gaillard
et al
. 2000). These fundamental studies have
focused on the relationships between population density,
weather and individual survival rates of different sex/
age classes (Gaillard, Festa-Bianchet & Yoccoz 1998;
Gaillard
et al
. 2000). Density-independent effects
(Milner-Gulland 1997; Smith & Anderson 1998; Coulson
et al
. 2001) also impact upon large mammal popula-
tions. There are often interactions between density-
dependent and density-independent effects, because
malnourished animals are more likely to succumb to
severe climatic events at high than at low population
densities (e.g. roe deer
Capreolus capreolus
, Gaillard
et al
. 1997; moose
Alces alces
, Crete & Courtois 1997;
bighorn sheep
Ovis canadensis
, Portier
et al
. 1998;
alpine ibex
Capra ibex
, Jacobson
et al
. 2004). More
importantly, it has become evident that the impacts of
both density-dependent and density-independent effects
vary substantially according to a population’s sex/age
structure. This is because the survival of different sex/ age
classes is not equally affected by resource abundance
and inclement weather. In general, adults are relatively
impervious to density and weather effects, while
juveniles (and possibly senescent individuals) are
highly susceptible to both (Gaillard, Festa-Bianchet &
Yoccoz 1998; Gaillard
et al
. 2000; Coulson
et al
. 2001).
This finding has crucial relevance to management strat-
egies, first because it underlines that population projec-
tion forecasts must take sex/age structure into account
(Gaillard, Loison & Toïgo 2003), and secondly because
it suggests possible fundamental differences in how
exploited and unexploited populations will react to
changes in density and weather. The proportion of
juveniles and yearlings (the age classes most sensitive to
both weather and density) tends to be much greater in
harvested than in unharvested populations, while the
proportion of senescent individuals (with higher
mortality and sometimes lower fecundity; Gaillard
et al
. 2000) is much lower (Langvatn & Loison 1999;
Apollino, Bassano & Mustoni 2003; Festa-Bianchet 2003;
Festa-Bianchet, Gaillard & Côté 2003). It therefore
seems reasonable to predict that the growth rate of
heavily harvested populations may vary more than that
of unharvested or lightly harvested populations in
response to changes in weather and density. This idea
merits further consideration, because much of our
current understanding of population dynamics in un-
gulates comes from long-term monitoring of unharvested
populations (Gaillard
et al
. 2000). In particular, un-
gulate populations subject to heavy harvest should show
steep declines following seasonally harsh weather
(because of the high proportion of juveniles) and pos-
sibly rapid increases following either mild weather or a
relaxation of harvest (because of the sudden influx of
young reproducing females, and the very high adult
survival given the young age structure). If those predic-
tions are correct, sport hunting, as currently practised
in many areas, may increase population variability,
the opposite of the often-stated goal of management
programmes (Fryxell
et al
. 1991; Langvatn & Loison
1999). Management programmes that target young of the
year for a substantial proportion of the harvest should
be less likely to increase the amplitude of weather-
related population fluctuations and more likely to
maintain an age structure not radically different from
that in naturally regulated populations.
Recent research on population dynamics of herbivores
has also underlined the importance of time lags in both
weather effects and density-dependence, because of a
combination of delays in the recovery of overgrazed
vegetation and the effects of changes in the age struc-
ture of the population (Saether 1997; Post & Stenseth
1998). An important applied consequence of time lags
1024
I. J. Gordon,
A. J. Hester &
M. Festa-Bianchet
© 2004 British
Ecological Society,
Journal of Applied
Ecology
,
41
,
1021–1031
in the population response of herbivores is that if
managers determine harvest quotas based on current
population estimates, they risk overharvesting declin-
ing populations and underharvesting recovering ones,
amplifying rather than dampening fluctuations in
population density. This has been reported for white-
tailed deer
Odocoileus virginianus
in Canada and
moose
Alces alces
in Scandinavia (Fryxell
et al
. 1991;
Solberg
et al
. 1999).
The saiga antelope
Saiga tartarica
L. demonstrates
the interaction between density-dependent and density-
independent effects on a species for which management
is critical for both the economy of local communities
and for saiga conservation. The saiga occupies the
semi-arid steppes of Kazakstan, Russia and Mongolia
(Bekenov, Grachev & Milner-Gulland 1998). Historic-
ally, the species was exploited for its meat in a regulated
fashion. However, with the opening of the Chinese
medicine market in the 1990s, there has been increasing
pressure on male saiga, the horns of which fetch a
high price (Chan, Maksimuk & Zhirnov 1995; Milner-
Gulland 1997), leading to a dramatic decline in numbers
(Sharp 2002). The species was listed under Appendix
II of the Convention on the International Trade in
Endangered Species of Wild Fauna and Flora (CITES)
in 1995 (Baillie & Groombridge 1996) and was assessed
as critically endangered by IUCN in 2002 (IUCN 2002;
http://www.redlist.org/). Saiga antelope populations
are characterized by large fluctuations in size, primarily
attributed to density-independent factors (Milner-
Gulland 1997; Coulson
et al
. 2001). Summer droughts
and severe winters affect birth rates of adult and
yearling females, and mortality of both young and
old animals. Recent modelling has suggested that
sustainable legal harvests of saiga can be achieved
through risk-averse management (Milner-Gulland
1997), with quotas set that account for vulnerability to
severe weather. This example demonstrates how an
increased understanding of density-independent
and density-dependent effects could be incorporated
into future models, which could then provide more
realistic predictions of population dynamics. However,
as has been demonstrated for saiga antelope over
the past 2 years, no amount of ecologically based
advice will save a species from decimation if legal
frameworks are not implemented to reduce poaching.
This requires an understanding of proximate causes
of poaching that include local poverty, lack of law
enforcement and open trade across national boarders
(Milner-Gulland
et al
. 2001; Sharp 2002). Currently,
saiga antelope cannot sustain any harvest (Milner-
Gulland
et al
. 2003).
To date most studies on large mammalian herbivores
have concentrated on temperate species (reviewed by
Gaillard
et al
. 2000) and have focused on long-term
monitoring programmes of a few populations, mostly
in the northern hemisphere and mostly unexploited
(Clutton-Brock, Guiness & Albon 1982; Festa-Bianchet,
Gaillard & Côté 2003). These populations may behave
differently from those in other environmental contexts,
or those subject to controlled harvests. As such there
are limits to the generalizations and extrapolations that
can be made from these studies. We encourage more
research to further our understanding of the impact of
intrinsic and extrinsic processes on population dynamics
in tropical ungulates, including predation (Messier
1994) and the effects of harvests on sex/age structure
and on age-specific vital rates (Sinclair 1977; Owen-Smith
1993; Mduma, Sinclair & Hilborn 1999).
Population response to age- and sex-specific
culling
Many management schemes prescribe sex-specific levels
of culling. Ecological research has demonstrated how
culling different sexes has very different impacts on
population dynamics (Mysterud, Coulson & Stenseth
2002). A failure to take this into account can lead to
unexpected and often undesirable consequences
(Gaillard, Loison & Toïgo 2003).
Many African antelope species have been put forward
as possible candidates for sustainable wildlife harvest-
ing schemes (Darling 1960), to the extent that attempts
were made in the 1970s to domesticate some species
(e.g. Lewis 1975). The impala
Aerycerus melampus
is a
medium-sized antelope, ubiquitous in the semi-arid
bush savannas of southern Africa (Kingdon 1972;
Smithers 1983). It is a highly social species in which the
females range in medium to large groups, with each
group accompanied by an adult male (Murray 1982).
As is common in many polygynous antelope species
(Jarman 1974), the males carry horns whereas the
females are hornless. Historically, the hunting pressure
on impala was very heavily male-biased as the species
was hunted for its trophy value (Fairall 1985). It was
suggested that male-biased hunting pressure may limit
population size because female fecundity may be
reduced when trophy males are removed (Fairall 1985;
Ginsberg & Milner-Gulland 1994). This was disputed
by other authors because young males can fertilize
females in the absence of trophy males (Mysterud,
Coulson & Stenseth 2002). In saiga antelope, however,
the sex-biased harvest is thought to have led to repro-
ductive collapse (Milner-Gulland
et al
. 2003).
Modelling, using parameters derived from auteco-
logical studies of impala, suggests that, under certain
circumstances, strongly sex- and age-biased hunting
(as occurs in game ranches and under trophy hunting)
can lead to population collapse in ungulates (Fairall
1985; Mysterud, Coulson & Stenseth 2002). This may
also be true in other species where males represent a
greater economic resource than females (e.g. elephant
Loxodonta africana
, Milner-Gulland & Mace 1991;
moose
Alces alces
, Solberg
et al
. 2002; but see Laurian
et al
. 2000; saiga
Saiga tartarica
, Milner-Gulland
et al
.
2003). For example, many hunted populations of
wapiti
Cervus elaphus canadensis
have post-hunt ratios of
five or fewer males per 100 females (Bender
et al
. 2002)
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Management of
wild large
herbivores
© 2004 British
Ecological Society,
Journal of Applied
Ecology
,
41
,
1021–1031
and few males survive past 4 years of age (Biederbeck,
Boulay & Jackson 2001), possibly affecting the timing
of conceptions (Noyes
et al
. 1996). Most of the evidence,
however, currently suggests that extreme sex ratio biases
(less than five males per 100 females) are required to
affect population productivity.
More recently, concerns have been raised about how
sport hunting mortality leads to sex- and age-specific
mortality rates that are radically different from those in
unhunted populations. Sport harvest may have evolu-
tionary consequences such as changes in life-history
parameters, as have been recorded in commercially
exploited fish, including changes in size and age at
maturity and possibly in reproductive effort (Jennings,
Reynolds & Mills 1998; Law 2001; Harris, Wall &
Allendorf 2002; Festa-Bianchet 2003; Olsen
et al
. 2004).
Recent evidence strongly suggests that high levels of trophy
hunting, whereby males with the largest horns are targeted,
can select for small-horned males over a few generations
(Coltman
et al
. 2003). It is becoming evident that managers
should consider evolution, as well as population dynamics,
in deciding which animals to cull. Moving towards ‘evo-
lutionarily enlightened management’ (Ashley
et al
. 2003)
will be a major challenge facing the management of
large herbivores over the next few years.
The link between sex-specific culling programmes
and trophy harvest opportunities is clearly demonstrated
in red deer, where recent research has concluded that
emigration of male red deer from natal areas increased
with female density (Clutton-Brock
et al
. 2002). The
authors incorporated this information into an economic
model to assess optimal culling strategies on Scottish
estates, taking account of deer numbers on neighbouring
estates. They advocated that to maximize economic
returns from hunting stags, estate managers should
reduce female densities to around 50% of the ecological
carrying capacity. This will reduce male emigration and
possibly encourage immigration from neighbouring
populations. However, this does not account for the
fact that stags may move large distances in search of
hinds during the mating season (mating commutes;
sensu
Hogg 2000). As the mating season coincides
with the hunting season in Scotland, stags are likely to
be shot on land holdings (estates) other than those
where they spend most of their lives (Sibbald, Hooper
& Gordon 2001). In bighorn sheep, ram movements
during the rut are affected by both social rank and the
relative availability of ewes in neighbouring populations.
Middle-ranking rams are more likely to move to ewe
groups up to 50 km away in years when there are few
breeding opportunities in their natal population (Hogg
2000). There is clearly a need to understand the role
of both short-term movement (mating commutes)
and long-term dispersal among hunted populations
(McCullouch 1996) and between hunted populations and
protected areas (Hogg 2000), if managers are to more
effectively account for metapopulation responses to
management strategies. Large-scale male movements
during the rut also demonstrate that biological processes
often occur at a much larger scale than that affected
by individual management plans, hence there is great
value in co-operation between different resource managers
to ensure that their management targets are not jeopard-
ized by the activities of others (see below, Managing large
herbivores to meet multiple objectives: the future).
Herbivore impacts on vegetation: local to
landscape
Herbivore distribution and associated impacts on
vegetation are scale-dependent (Senft
et al
. 1987;
Bailey
et al
. 1996; Roguet, Dumont & Prache 1998;
Rietkerk
et al
. 2000). It is, therefore, fundamentally
important to understand the scales of impact driving
vegetation or landscape change in large herbivore
dominated ecosystems. For example, at the landscape
scale heavy grazing may lead to increasing dominance
of grazing-tolerant or unpreferred plant species that may
reduce diversity, whereas at local scales heavy pressure
on preferred vegetation might locally increase diversity
through the provision of new germination niches by
trampling or improved nutrient cycling (Crawley 1997).
Large herbivores generally have extensive ranges, and
therefore their management tends to be focused at a large
scale, which may not be the most appropriate scale of
management for the resources themselves (Palmer
et al
.
2003). Much work has been done to define desirable
densities of different herbivores for particular aims, and
to explore how culling or other management regimes
should be employed to achieve those aims (Welch 1984;
Beaumont
et al
. 1994). Other studies have focused on the
vegetation responses to grazing pressure (utilization
rates) rather than on management through fixed her-
bivore densities, particularly in grass–shrub systems
(Archer 1996; Armstrong
et al
. 1997). Without a full
understanding of what drives herbivores to distribute
themselves across the landscape, however, all these
‘large-scale’ approaches have their limitations.
Ecological research has shown how key resources,
such as vegetation, water and shelter, together with aspects
of herbivore sociability and gregariousness, all drive the
distribution of herbivores and thus their impacts on
resources at a range of scales (Hunter 1962; Kolasa &
Pickett 1991; Milchunas & Lauenroth 1993; Schaefer
& Messier 1995; Bailey, Dumont & Wallis de Vries
1998; Pastor
et al
. 1998; Illius & O’Connor 2000; Apps
et al
. 2001). Much of this research suggests that the
distribution of herbivores is primarily determined by
abiotic factors, such as terrain or distance to shelter/water,
and herbivore responses to vegetation heterogeneity
operate within these higher level constraints (Bailey
et al
. 1996; Tainton, Morris & Hardy 1996; Adler, Raff
& Lauenroth 2001; Landsberg
et al
. 2003). The effects
of vegetation heterogeneity on herbivore distribution
are complex. Herbivores are generally attracted to pre-
ferred vegetation, but the spatial relationship between
preferred and non-preferred vegetation is of para-
mount importance in driving the system dynamics
1026
I. J. Gordon,
A. J. Hester &
M. Festa-Bianchet
© 2004 British
Ecological Society,
Journal of Applied
Ecology
,
41
,
1021–1031
(Reichman, Benedix & Seastedt 1993; Archer 1996;
Hester
et al
. 1999; Illius & O’Connor 2000; Palmer
et al
. 2003). Recent research has clearly shown that dif-
ferent spatial patterns of vegetation types can change
herbivore behaviour and their concomitant impacts on
the dynamics of the vegetation itself (Clarke, Welch &
Gordon 1995; Wallis de Vries 1996; Illius & O’Connor
2000; Oom
et al
. 2002). For example, Palmer
et al
.
(2003) examined the impacts of red deer on heather
Calluna vulgaris
moorland. As predicted from previous
studies (Clarke, Welch & Gordon 1995; Hester & Baillie
1998), patterns of impact on heather were strongly linked
with its location relative to preferred grass patches
(at a 1-km
2
scale or less), demonstrating that it was
impossible to predict the severity and pattern of heather
utilization from only management-scale (> 100 km
2
)
parameters such as herbivore density and total area
of grassland (Stohlgren, Schell & van den Heuvel
1999; Ryerson & Parmenter 2001). Thus, it appears
as though the impacts of large herbivores on non-
preferred resources are most strongly driven by the
position of these resources relative to preferred res-
ources (Ball, Danell & Sunesson 2000). The success of
large-scale herbivore management to control impacts
on vegetation is unpredictable, because of the weakness
of the relationship between herbivore density and dis-
tribution of foraging impact in large, heterogeneous
areas. These studies demonstrate that, before accurate
predictions can be made about the consequences of dif-
ferent natural resource management scenarios, there
has to be a shift of focus from simple consideration of
the relative abundance of different resources and/or
species (Archer 1996), to a consideration of their spa-
tial distribution within the landscape. Refinements to
management might include ‘artificial’ manipulation of
localized vegetation composition (e.g. through targeted
grazing by domestic stock), with the aim of manipulat-
ing the distribution of other, free-ranging herbivores in
the area (Gordon 1989). For example, if herbivore use
of a vulnerable, highly preferred area of vegetation is
‘unacceptably’ high even after major reductions in
overall herbivore densities, manipulation of the vege-
tation elsewhere could alter herbivore distributions
and consequently their impact (Rea 2003). When linked
to spatially explicit process models (Boone
et al
. 2002),
new technology, such as remote sensing, GPS and
GIS, will be able to provide valuable information at the
appropriate spatial scale for informing management
decisions (Sibbald & Gordon 2001; Danks & Klein
2002; Johnson
et al
. 2002; Stalmans, Witkowski &
Balkwill 2002).
Implications for biodiversity conservation
With increasing concern for biodiversity and conserva-
tion internationally, many countries have now signed
agreements targeted at specific plant or animal species
and habitats designated as of international or national
importance (Department of the Environment 1994;
CITES, http://www.cites.org/). These obligations require
strong, underpinning ecological knowledge upon which
to devise appropriate management regimes to achieve
the agreed targets. However, in many cases these obli-
gations highlighted a widespread lack of understand-
ing of what drives the impacts of free-ranging large
herbivores on biodiversity (Wallis de Vries 1996).
Notwithstanding the fundamentally important effects
of abiotic factors, maximization of vegetation diversity
in a landscape is widely hypothesized to require inter-
mediate levels of herbivory (Grime 1973; Crawley
1997; Olff & Ritchie 1998; Ritchie & Olff 1999; Bullock
et al
. 2001), although definitions of ‘intermediate’ are
not always easy. To integrate the management of large
herbivores with biodiversity/environmental objectives,
the relationships between grazing and biodiversity
must be understood. A recurring problem, however,
has been that many experimental treatments of ecosys-
tems have tended to be either grazing ‘on’ (unknown
grazing species’ contribution to grazing pressure,
unknown herbivore density, unknown seasonality of
grazing) or grazing ‘off’ (using exclosures) (Hester
et al
. 2000). ‘Exclosure’ use as a management tool has
already highlighted the inappropriateness or short-term
nature of the ‘benefits’ of simple removal of herbivores,
rather than manipulation of their densities. But managers
are unlikely to develop management plans based on
varying wild herbivore densities until qualitative theor-
etical hypotheses about desirable herbivore impacts
can be expressed as recommendations for actual densities
under a range of different conditions. This problem is
gradually being redressed (Bullock 1996; Bullock
et al
.
2001) but generally requires complex or costly experi-
mental designs and careful measurement of all key
driving factors in different systems, before widespread
practical generalizations can be made.
One example of the widespread use of grazing
removal, to conserve or expand a vulnerable habitat, as
opposed to the manipulation of herbivore density,
is the case of woodland regeneration in Scotland.
Native woodland and scrub now covers less than 4% of
Scotland’s land area (Mackenzie 1999), yet theoretically
it could cover more than 50% (Towers
et al
. 2004).
Many woodland communities and some of their
associated plant and animal species have now been
designated for protection and/or expansion under the
UK Habitats and Species Directive. Grazing is thought
to have played a major role in woodland decline
across the whole of the UK (Birks 1988; Milne
et al
.
1998), and the impacts of both red deer and sheep in
suppressing regeneration have been clearly demon-
strated (Beaumont
et al
. 1994; Hester, Mitchell & Kirby
1996; Miller, Cummins & Hester 1998). Elsewhere in
Europe, widespread deforestation and suppression
of regeneration by large herbivores is also a major problem
(Humphrey, Gill & Claridge 1998; Hester
et al
. 2004),
with several European countries having designations
to protect and expand such habitats. The knock-on
effects of forest declines of such magnitude on other
1027
Management of
wild large
herbivores
© 2004 British
Ecological Society,
Journal of Applied
Ecology
,
41
,
1021–1031
aspects of biodiversity are relatively poorly understood
(Hester
et al
. 2000). One exclosure study, for example,
found higher densities of invertebrate species in un-
grazed Scottish native pinewoods than in grazed
pinewoods (Baines, Sage & Baines 1994). To date,
where woodland cover is now greatly restricted, fencing
has been widely used as a ‘quick fix’ in protecting
woodland sites and encouraging regeneration. How-
ever, problems associated with fencing include deaths
of protected species such as woodland grouse (e.g.
capercaillie
Tetrao urogallus
), high cost, frequent snow
damage, adverse landscape impact and problems asso-
ciated with higher densities of wild herbivores in the
surrounding areas due to loss of land within their range
(Hester
et al
. 2000).
Managing large herbivores to meet multiple
objectives: the future
The future management of wild large herbivores will
require ecologists to co-operate with sociologists, econ-
omists, politicians and the public. As shown by the
severe decline of the saiga (Milner-Gulland
et al
. 2003)
and the reintroduced Arabian oryx
Oryx leucoryx
(Spalton, Lawrence & Brend 1999), it is irrelevant how
much information from ecological research is provided
to policy makers for the conservation of target species
if other factors are not taken into account. For ex-
ample, if herbivore populations are being decimated
by poaching because of local poverty, lack of law en-
forcement and open illegal trade across national borders,
then these sociological issues must be addressed. If they
are not brought under control, extinction is a real
likelihood for many large herbivore species (Ludwig,
Hilborn & Walters 1993). The management of large
herbivores must undergo a sea-change, where the
ecological understanding of population dynamics and
habitat relationships is linked with socio-economic
studies that address the issues relating to human–wildlife
interactions (du Toit, Walker & Campbell 2004).
In many countries, wildlife (usually referring only to
large mammals) belongs to the state and the right to
hunt wildlife is regulated by a government, as is the
protection of wildlife within national parks and
reserves (Geist 1994). Over the past two decades, par-
ticularly in developing countries, there has been a shift
in government policy towards handing over the right to
use, if not the ownership of, wildlife outside protected
areas to local communities (Harris & Shilai 1997;
Hulme & Murphree 2001; but see Prins, Grootenhuis &
Dolan 2000). This change in approach is derived from
the philosophy that, in order to conserve wildlife out-
side protected areas, local people must derive some
benefit (usually financial) that outweighs the costs of
co-existing with that wildlife (Murphree 1998). Much
research has been concentrated on the benefits of the
community conservation approach to rural economies
and people’s attitude to wildlife (Hulme & Murphree
2001). Ecological research is now required to help local
communities determine the most effective ways of
managing wildlife in their area (Féron
et al
. 1998; De
Garine & de Garine-Wichatitsky 1999) and to provide
cost-effective means of population assessment. Costly
aerial surveys (Jolly 1969; du Toit 2002; Jachmann 2002)
are inappropriate in this context but low-cost methods
could be employed, such as dung surveys (Laing
et al
.
2003), bicycle surveys (Gaidet, Fritz & Nyahuma
2003) or by using information from culls and harvests
(e.g. age structure and fecundity rates). Over time, indi-
ces of population responses to environmental condi-
tions and management decisions should become
available. While there are arguments as to the value of
this approach to wildlife conservation (Hulme &
Murphree 2001; du Toit, Walker & Campbell 2004), the
philosophy is still valid and should be adopted in
developed countries, where local communities could be
encouraged to have a more positive attitude towards
wildlife in their local area.
The home range of wild herbivores often extends
over land held under more than one ownership, pro-
viding an additional challenge to management. To
date, the management of ungulate populations has
tended to focus on the management of single popula-
tions within defined management units, for example
estates, community lands and nature reserves/national
parks. Ecological research needs to develop a more
detailed understanding of the interactions between
subpopulations (e.g. immigration and emigration rates)
and the consequences of management of one popula-
tion on neighbouring populations, especially where the
management units have very different goals (e.g. hunt-
ing and conservation). The outcomes of this research
should be coupled with policy and management instru-
ments that facilitate the co-operative management of
large herbivore populations. Management units must
more closely reflect the biology of the populations rather
than the human-defined ownership and jurisdictional
boundaries. In many respects, the developing world is
leading the way in approaches to public involvement in
management and co-operative management, and the
developed world would do well to learn from the relative
success or otherwise of different attempts to manage
large herbivore populations more holistically, as part
of a socio-ecological system rather than in isolation.
Acknowledgements
Thanks go to Jean-Michel Gaillard, Glenn Iason, Norman
Owen Smith, Robin Pakeman and an anonymous referee
for their valuable comments on the manuscript. I.J.G.
and A.J.H. acknowledge the support of the Scottish
Executive Environment and Rural Affairs Department.
In addition, I.J.G. was supported by CSIRO.
References
Adler, P.B., Raff, D.A. & Lauenroth, W.K. (2001) The effect
of grazing on the spatial heterogeneity of vegetation. Oecologia,
128, 465–479.
1028
I. J. Gordon,
A. J. Hester &
M. Festa-Bianchet
© 2004 British
Ecological Society,
Journal of Applied
Ecology, 41,
1021–1031
Apollino, M., Bassano, B. & Mustoni, A. (2003) Behavioral
aspects of conservation and management of European
mammals. Animal Behavior and Wildlife Conservation (eds
M. Festa-Bianchet & M. Apollino), pp. 157–170. Island
Press, Washington, DC.
Apps, C.D., Mclellan, B.N., Kinley, T.A. & Flaa, J.P. (2001)
Scale-dependent habitat selection by mountain caribou,
Columbia Mountains, British Columbia. Journal of Wild-
life Management, 65, 65–77.
Archer, S. (1996) Assessing and interpreting grass: woody
plant dynamics. The Ecology and Management of Grazing
Systems (eds J. Hodgson & A.W. Illius), pp. 101–134. CAB
International, Wallingford, UK.
Armstrong, H.M., Gordon, I.J., Sibbald, A.R., Hutchings,
N.J., Illius, A.W. & Milne, J.A. (1997) A model of grazing by
sheep on hill systems in the UK. II. The prediction of
offtake by sheep. Journal of Applied Ecology, 34, 186–207.
Ashley, M.V., Willson, M.F., Pergams, O.R.W., O’Dowd, D.J.,
Gende, S.M. & Brown, J.S. (2003) Evolutionarily enlightened
management. Biological Conservation, 111, 115–123.
Bailey, D.W., Dumont, B. & Wallis de Vries, M.F. (1998)
Utilization of heterogeneous grassland by domestic
herbivores: theory to management. Annales Zootechnie, 47,
321–333.
Bailey, D.W., Gross, J.E., Laca, E.A., Rittenhouse, L.R.,
Coughenour, M.B., Swift, D.M. & Sims, P.L. (1996) Mech-
anisms that result in large herbivore grazing distribution
patterns. Journal of Range Management, 49, 386– 400.
Baillie, J. & Groombridge, B. (1996) 1996 IUCN Red List of
Threatened Animals. International Union for the Con-
servation of Nature, Gland, Switzerland.
Baines, D., Sage, R.B. & Baines, M.M. (1994) The implications
of red deer grazing to ground vegetation and invertebrate
communities of Scottish native pinewoods. Journal of Applied
Ecology, 31, 776–783.
Ball, J.P., Danell, K. & Sunesson, P. (2000) Response of a her-
bivore community to increased food quality and quantity:
an experiment with nitrogen fertilizer in a boreal forest.
Journal of Applied Ecology, 37, 247–255.
Barnes, J.I., Schier, C. & van Rooy, G. (1999) Tourists’ will-
ingness to pay for wildlife viewing and wildlife conservation
in Namibia. South African Journal of Wildlife Research, 29,
101–111.
Beard, P. (1988) The End of the Game. Chronicle Books, San
Francisco, CA.
Beaumont, D., Dugan, D., Evans, G. & Taylor, S. (1994)
Deer management and tree regeneration in the RSPB
reserve at Abernethy Forest. Our Pinewood Heritage
(ed. J.R. Aldhous), pp. 186–195. Forestry Commission,
Edinburgh, UK.
Bekenov, A.B., Grachev, I.A. & Milner-Gulland, E.J. (1998)
The ecology and management of the saiga antelope in
Kazakhstan. Mammal Review, 28, 1–52.
Bender, L., Fowler, P.E., Bernatouwicz, J.A., Masser, J.L.
& Stream, L.E. (2002) Effects of open-entry spike-bull,
limited-entry branched-bull harvesting on elk composition
in Washington. Wildlife Society Bulletin, 30, 1078–1084.
Biederbeck, H.H., Boulay, M.C. & Jackson, D.H. (2001)
Effects of hunting regulations on bull elk survival and age
structure. Wildlife Society Bulletin, 29, 1271–1277.
Birks, H.J.B. (1988) Long-term ecological change in the
British uplands. Ecological Change in the Uplands (eds
M.B. Usher & D.B.H. Thompson), pp. 37–56. Blackwell
Scientific Publications, Oxford, UK.
Bodmer, R.E., Fang, T.G. & Ibanez, L.M. (1988) Ungulate
management and conservation in the Peruvian Amazon.
Biological Conservation, 45, 303–3310.
Boone, R.B., Coughenour, M.B., Galvin, K.A. & Ellis, J.E.
(2002) Addressing management questions for Ngorongoro
Conservation Area, Tanzania, using the SAVANNA model-
ling system. African Journal of Ecology, 40, 138–150.
Bowen-Jones, E. & Entwistle, A. (2002) Identifying appropri-
ate flagship species: the importance of culture and local
contexts. Oryx, 36, 189–195.
Bullock, J.M. (1996) Plant competition and population
dynamics. The Ecology and Management of Grazing Sys-
tems (eds J. Hodgson & A.W. Illius), pp. 69–100. CAB
International, Wallingford, UK.
Bullock, J.M., Franklin, J., Stevenson, M.J., Silvertown, J.,
Coulson, S.J., Gregory, S.J. & Tofts, R. (2001) A plant trait
analysis of responses to grazing in a long-term experiment.
Journal of Applied Ecology, 38, 253–267.
Caughley, G. & Sinclair, A.R.E. (1994) Wildlife Ecology and
Management. Blackwell Science, Oxford, UK.
Chan, S., Maksimuk, A.V. & Zhirnov, L.V. (1995) From
Steppe to Store: The Trade in Saiga Antelope Horn. Species
in Danger Series. TRAFFIC, Cambridge, UK.
Clarke, J.L., Welch, D. & Gordon, I.J. (1995) The influence of
vegetation pattern on the grazing of heather moorland by
red deer and sheep. II. The impact on heather. Journal of
Applied Ecology, 32, 177–186.
Clutton-Brock, T.H., Coulson, T.N., Milner-Gulland, E.J.,
Thomson, D. & Armstrong, H.M. (2002) Sex differences in
emigration and mortality affect optimal management of
deer populations. Nature, 415, 633– 637.
Clutton-Brock, T.H., Guiness, F.E. & Albon, S.D. (1982) Red
Deer, Behavior and Ecology of Two Sexes. University of
Chicago Press, Chicago, IL.
Coltman, D.W., O’Donoghue, P., Jorgenson, J.T., Hogg, J.T.,
Strobeck, C. & Festa-Bianchet, M. (2003) Undesirable
evolutionary consequences of trophy hunting. Nature, 426,
655–658.
Conover, M.R. (1997) Monetary and intangible valuation of
deer in the United States. Wildlife Society Bulletin, 25, 298–
305.
Coulson, T., Mace, G.M., Hudson, E. & Possingham, H.
(2001) The use and abuse of population viability analysis.
Trends in Ecology and Evolution, 16, 219– 221.
Crete, M. & Courtois, R. (1997) Limiting factors might
obscure population regulation of moose (Cervidae: Alces
alces) in unproductive boreal forests. Journal of Zoology,
London, 242, 765–781.
Crawley, M.J. (1997) Plant Ecology, 2nd edn. Blackwell
Science, Oxford, UK.
Dale, V.H., Brown, S., Haeuber, R.A., Hobbs, N.T., Huntly,
N., Naiman, R.J., Riebsame, W.E., Turner, M.G. & Valone,
T.J. (2000) Ecological principles and guidelines for manag-
ing the use of land. Ecological Applications, 10, 639–670.
Danell, K., Bergström, R., Duncan, P., Pastor, J. & Olff, H.
(in press) Large Herbivore Ecology and Ecosystem Dynamics.
Cambridge University Press, Cambridge, UK.
Danks, F.S. & Klein, D.R. (2002) Using GIS to predict potential
wildlife habitat: a case study of muskoxen in northern Alaska.
International Journal of Remote Sensing, 23, 4611–4632.
Danz, H.P. (1997) Of Bison and Man: from the Annals of a
Bison Yesterday to a Refreshing Outcome from Human
Involvement with America’s Most Valiant of Beasts. Colorado
University Press, Boulder, COL.
Darling, F.F. (1960) An ecological reconnaissance of the Mara
plains in Kenya Colony. Wildlife Monographs, 5, 1–41.
De Garine, I. & de Garine-Wichatitsky, M. (1999) Providing
impala meat (Aepyceros melampus) to local populations
in Nyaminyami (Omay, Zimbabwe). Bois et Forêts des
Tropiques, 262, 61–73.
Department of the Environment (1994) Biodiversity: The UK
Action Plan. HMSO, London, UK.
Du Toit, J.T. (2002) Wildlife harvesting guildelines for community-
based wildlife management: a southern African perspective.
Biodiversity and Conservation, 11, 1403–1416.
Elton, C.S. (1924) Periodic fluctuations in the number of animals:
their causes and effects. British Journal of Experimental
Biology, 2, 119–163.
1029
Management of
wild large
herbivores
© 2004 British
Ecological Society,
Journal of Applied
Ecology, 41,
1021–1031
Fairall, N. (1985) Manipulation of age and sex-ratios to optimize
production from impala Aepyceros melampus populations.
South African Journal of Wildlife Research, 15, 85–88.
Féron, E., Tafira, J.K., Belemsobgo, U., Blomme, S. &
Garine-Wichatitsky (de), M. (1998) Transforming wild
African herbivores into edible meat for local communities.
A community owned mechanism for the sustainable use of
impala (Aepyceros melampus) in the CAMPFIRE Pro-
gramme, Zimbabwe. Revue Elevage et Médecine Vétérinaire
Pays Tropicale, 51, 265–272.
Festa-Bianchet, M. (2003) Exploitative wildlife management
as a selective pressure for the life-history evolution of large
mammals. Animal Behavior and Wildlife Conservation (eds
M. Festa-Bianchet & M. Apollonio), pp. 191–207. Island
Press, Washington, DC.
Festa-Bianchet, M., Gaillard, J.-M. & Côté, S.D. (2003)
Variable age structure and apparent density-dependence in
survival of adult ungulates. Journal of Animal Ecology, 72,
640–649.
Fryxell, J.M., Hussell, D.J.T., Lambert, A.B. & Smith, P.C.
(1991) Time lags and population fluctuations in white-
tailed deer. Journal of Wildlife Management, 55, 377– 385.
Gaidet, N., Fritz, H. & Nyahuma, C. (2003) A participatory
method to monitor populations of large mammals in non-
protected areas: a case study of bicycle counts in the Zambezi
Valley. Biodiversity and Conservation, 12, 1571–1585.
Gaillard, J.M., Boutin, J.M., Delorme, D., Van Laere, G.,
Duncan, P. & Lebreton, J.D. (1997) Early survival in roe
deer: causes and consequences of cohort variation in two
contrasted populations. Oecologia, 112, 502– 513.
Gaillard, J.-M., Festa-Bianchet, M. & Yoccoz, N.G. (1998)
Population dynamics of large herbivores: variable recruit-
ment with constant adult survival. Trends in Ecology and
Evolution, 13, 58– 63.
Gaillard, J.-M., Festa-Bianchet, M., Yoccoz, N.G., Loison, A.
& Toigo, C. (2000) Temporal variation in fitness com-
ponents and population dynamics of large herbivores. Annual
Review of Ecology and Systematics, 31, 367–393.
Gaillard, J.-M., Loison, A. & Toïgo, C. (2003) Variation in life
history traits and realistic population models for wildlife
management: the case of ungulates. Animal Behavior and
Wildlife Conservation (eds M. Festa-Bianchet & M. Apollonio),
pp. 115–132. Island Press, Washington, DC.
Geist, V. (1994) Wildlife conservation as wealth. Nature, 368,
491–492.
Georgiadis, N., Hack, M. & Turpin, K. (2003) The influence
of rainfall on zebra population dynamics: implications for
management. Journal of Applied Ecology, 40, 125–136.
Gill, R.M.A. (1990) Monitoring the Status of European and
North American Cervids. Information Series 8. Global
Environment Monitoring System, United Nations Environ-
ment Programme, Nairobi, Kenya.
Gill, R.M.A. (1992) A review of damage by deer in north
temperate forests. I. Deer. Forestry, 65, 145–169.
Ginsberg, J.R. & Milner-Gulland, E.J. (1994) Sex-biased
harvesting and population dynamics in ungulates: implications
for conservation and sustainable use. Conservation Biology,
8, 157–166.
Gordon, I.J. (1989) Vegetation community selection by ungulates
on the Isle of Rhum. II. Vegetation community selection.
Journal of Applied Ecology, 26, 53–64.
Grime, J.P. (1973) Competitive exclusion in herbaceous vegeta-
tion. Nature, 242, 344– 347.
Harris, R.B. & Shilai, M. (1997) Initiating a hunting ethic in
Lisu villages, western Yunnan, China. Mountain Research
and Development, 17, 171–176.
Harris, R.B., Wall, W.A. & Allendorf, F.W. (2002) Genetic
consequences of hunting: what do we know and what
should we do? Wildlife Society Bulletin, 30, 634– 643.
Hester, A.J. & Baillie, G.J. (1998) Spatial and temporal pat-
terns of heather use by sheep and red deer within natural
heather/grass mosaics. Journal of Applied Ecology, 35, 772 –
784.
Hester, A.J., Edenius, L., Buttenshøn, R.M. & Kuiters, A.T.
(2000) Interactions between forests and herbivores: the role
of controlled grazing experiments. Forestry, 73, 381–391.
Hester, A.J., Gordon, I.J., Baillie, G.J. & Tappin, E. (1999)
Foraging behaviour of sheep and red deer within natural heather /
grass mosaics. Journal of Applied Ecology, 36, 133–146.
Hester, A.J., Millard, P., Baillie, G.J. & Wendler, R. (2004)
How does timing of browsing affect above- and below-ground
growth of Betula pendula, Pinus sylvestris and Sorbus
aucuparia? Oikos, 105, 536–550.
Hester, A.J., Mitchell, F.J.G. & Kirby, K.J. (1996) Effects of
season and intensity of sheep grazing on tree regeneration
in a British upland woodland. Forest Ecology and Manage-
ment, 88, 99–106.
Hobbs, N.T. (1996) Modification of ecosystems by ungulates.
Journal of Wildlife Management, 60, 695–713.
Hogg, J.T. (2000) Mating systems and conservation at large
spatial scales. Vertebrate Mating Systems (eds M. Apollonio,
M. Festa-Bianchet & D. Mainardi), pp. 214–252. World
Scientific, Toh Tuck Link, Singapore.
Hulme, D. & Murphree, M. (2001) African Wildlife and Live-
lihoods. The Promise and Performance of Community Con-
servation. James Curry Ltd, Oxford, UK.
Humphrey, J.W., Gill, R.M. & Claridge, J. (1998) Grazing as a
Management Tool in European forest Ecosystems. Technical
Paper 25. Forestry Commission, Edinburgh, UK.
Hunter, R.F. (1962) Hill sheep and their pasture: a study of
sheep-grazing in south east Scotland. Journal of Ecology,
50, 651–680.
Illius, A.W. & O’Connor, T.G. (2000) Resource heterogeneity
and ungulate population dynamics. Oikos, 89, 283–294.
IUCN (2002) Red Data Book. International Union for the Con-
servation of Nature., Gland Switzerland. http://www.redlist.org/
Jachmann, H. (2002) Comparison of aerial counts with
ground counts for large African herbivores. Journal of
Applied Ecology, 9, 841–852.
Jacobson, A.R., Provenzale, A., Hardenberg, A.V., Bassano, B.
& Festa-Bianchet, M. (2004) Climate forcing and density-
dependence in a mountain ungulate population. Ecology,
85, 1598–1610.
Jarman, P.J. (1974) The social organisation of antelope in rela-
tion to their ecology. Behaviour, 48, 215–267.
Jennings, S., Reynolds, J.D. & Mills, S.C. (1998) Life history
correlates of responses to fisheries exploitation. Proceedings
of the Royal Society, B, 265, 333–339.
Johnson, C.J., Parker, K.L., Herad, D.C. & Gillingham, M.P.
(2002) Movement parameters of ungulates and scale-
specific responses to the environment. Journal of Animal
Ecology, 71, 225–235.
Jolly, G.M. (1969) Sampling methods for aerial censuses of
game animals. East African Agricultural Forestry Journal,
34, 46–49.
Kingdon, J. (1972) East African Mammals: An Atlas of
Evolution in Africa. Academic Press, London, UK.
Kirby, K. (2001) Where have all the flowers gone? Are our
woodland flowers disappearing? Biologist, 48, 182 –186.
Kolasa, J. & Pickett, S.T. (1991) Ecological Heterogeneity.
Ecological Studies 86. Springer Verlag, Berlin, Germany.
Laing, S.E., Buckland, S.T., Burn, R.W., Lambie, D. &
Amphlett, A. (2003) Dung and nest surveys: estimating
decay rates. Journal of Applied Ecology, 40, 1102–1111.
Landsberg, J., James, C.D., Morton, S.R., Muller, W.J. & Stol,
J. (2003) Abundance and composition of plant species
along grazing gradients in Australian rangelands. Journal
of Applied Ecology, 40, 1008–1024.
Langvatn, R. & Loison, A. (1999) Consequences of harvest-
ing on age structure, sex ratio and population dynamics of
red deer Cervus elaphus in central Norway. Wildlife Biology,
5, 213–223.
1030
I. J. Gordon,
A. J. Hester &
M. Festa-Bianchet
© 2004 British
Ecological Society,
Journal of Applied
Ecology, 41,
1021–1031
Laurian, C., Ouellet, J.P., Courtois, R., Breton, L. & St-Onge, S.
(2000) Effects of intensive harvesting on moose reproduction.
Journal of Applied Ecology, 37, 515–531.
Law, R. (2001) Phenotypic and genetic changes due to
selective exploitation. Conservation of Exploited Species (eds
J.D. Reynolds, G.M. Mace, K.H. Redford & J.G. Robinson),
pp. 323– 342. Cambridge University Press, Cambridge, UK.
Leader-Williams, N., Smith, R.J. & Walpole, M.J. (2001) Eleph-
ant hunting and conservation. Science, 293, 2203–2204.
Lewis, J.G. (1975) A comparative study of the activity of some
indigenous East African ungulates and conventional stock
under domestication. Unpublished PhD Thesis. University
of London, London, UK.
Loibooki, M., Hofer, H., Campbell, K.L.I. & East, M.L.
(2002) Bushmeat hunting by communities adjacent to the
Serengeti National Park, Tanzania: the importance of live-
stock ownership and alternative sources of protein and
income. Environmental Conservation, 29, 391–398.
Ludwig, D., Hilborn, R. & Walters, C. (1993) Uncertainty,
resource exploitation, and conservation: lessons from his-
tory. Science, 260, 17–18.
Mackenzie, N. (1999) The Native Woodland Resource of
Scotland. A Review 1993–98. Technical Paper 30. Forestry
Commission, Edinburgh, UK.
McCullough, D.R. (1996) Spatially structured populations
and harvest theory – Invited paper. Journal of Wildlife
Management, 60, 1–9.
McShea, W.J., Underwood, H.B. & Rappole, J.H. (1997) The
Science of Overabundance. Deer Ecology and Population
Management. Smithsonian Institution Press, Washington,
DC.
Malo, J.E., Suárez, F. & Díez, A. (2004) Can we mitigate
animal–vehicle accidents using predictive models? Journal
of Applied Ecology, 41, 701–710.
Martin, P. (1993) Vegetation responses and feedbacks to
climate: a review of models and processes. Climate Dynamics,
8, 201–210.
Mduma, S.A.R., Sinclair, A.R.E. & Hilborn, R. (1999) Food
regulates the Serengeti wildebeest: a 40-year record. Journal
of Animal Ecology, 68, 1101–1122.
Messier, F. (1994) Ungulate population models with predation:
a case study with the North American moose. Ecology, 75,
478–488.
Milchunas, D.G. & Lauenroth, W.K. (1993) Quantitative effects
of grazing on vegetation and soils over a global range of
environments. Ecological Monographs, 63, 327–366.
Miles, J. (1985) The pedogenic effects of different species and
vegetation types and the implications of succession. Journal
of Soil Science, 36, 571–584.
Miller, G.R., Cummins, R. & Hester, A.J. (1998) Red deer and
woodland regeneration in the Cairngorms. Scottish For-
estry, 52, 14–20.
Milne, J.A., Birch, C.P.D., Hester, A.J., Armstrong, H.M. &
Robertson, A. (1998) The impact of vertebrate herbivores
on the natural heritage of the Scottish uplands: a review.
Scottish Natural Heritage Review, 95, 1–127.
Milner-Gulland, E.J. (1997) A stochastic dynamic programming
model for the management of the saiga antelope. Ecological
Applications, 7, 130–142.
Milner-Gulland, E.J. & Mace, R.H. (1991) The impact of the
ivory trade on the elephant population of the trade, as
assessed by data from the trade. Biological Conservation,
55, 215–229.
Milner-Gulland, E.J., Bukreeva, O.M., Coulson, T.,
Lushchekina, A.A., Kholodova, M.V., Bekenov, A.B.
& Grachev, I.A. (2003) Reproductive collapse in a harem-
breeding ungulate. Nature, 422, 135.
Milner-Gulland, E.J., Kholodova, M.V., Bekenov, A.,
Bukreeva, O.M., Grachev, I.A., Amgalan, L. & Lushchekina,
A.A. (2001) Dramatic declines in saiga antelope populations.
Oryx, 35, 340–345.
Murphree, M.W. (1998) Ex Africa simper aliquid novi?
Considerations in linking African environmental scholarship,
policy and practice. Communities and Sustainable Use: Pan-
African Perspectives (eds N. Christoffersen, B. Campbell &
J. du Toit), pp. 3–7. IUCN, Gland, Switzerland.
Murphree, M. (2001) A case study in ecotourism development
from Mahenye, Zimbabwe. African Wildlife and Livelihoods.
The Promise and Performance of Community Conservation
(eds D. Hulme, & M. Murphree), pp. 177–194. James Curry
Ltd, Oxford, UK.
Murray, M.G. (1982) Home range, dispersal and the clan sys-
tem of impala. African Journal of Ecology, 20, 53–269.
Mysterud, A., Coulson, T. & Stenseth, N.C. (2002) The role of
males in the dynamics of ungulate populations. Journal of
Animal Ecology, 71, 907–915.
Noyes, J.H., Johnson, B.K., Bryant, L.D., Findholt, S.L. &
Thomas, J.W. (1996) Effects of bull age on conception dates
and pregnancy rates of cow elk. Journal of Wildlife Man-
agement, 60, 508–517.
Ogutu, Z.A. (2002) The impact of ecotourism on livelihood and
natural resource management in Eselenkei, Amboseli ecosystem,
Kenya. Land Degradation and Development, 13, 251–256.
Olff, H. & Ritchie, M.E. (1998) Effects of herbivores on grass-
land plant diversity. Trends in Ecology and Evolution, 13,
261–265.
Olsen, E.M., Heino, M., Lilly, G.R., Morgan, M.J., Brattey,
J., Ernande, B. & Dieckmann, U. (2004) Maturation trends
indicative of rapid evolution preceded the collapse of north-
ern cod. Nature, 428, 932–935.
Oom, S.P., Hester, A.J., Elston, D.A. & Legg, C.J. (2002)
Spatial interaction models: from human geography to
plant–herbivore interactions. Oikos, 98, 65–74.
Owen-Smith, N. (1993) Comparative mortality rates of male
and female kudus: the costs of sexual size dimorphism.
Journal of Animal Ecology, 62, 428–440.
Palmer, S.C.F., Hester, A.J., Elston, D.A., Gordon, I.J. &
Hartley, S.E. (2003) The perils of having tasty neighbors:
grazing impacts of large herbivores at vegetation bounda-
ries. Ecology, 84, 2877–2890.
Pastor, J., Dewey, B., Moen, R., Mladenoff, D.J., White, M. &
Cohen, Y. (1998) Spatial patterns in the moose–forest–soil
ecosystem on Isle Royale, Michigan, USA. Ecological
Applications, 8, 411–424.
Pickup, G., Bastin, G.N. & Chewings, V.H. (1998) Identifying
trends in land degradation in non-equilibrium rangelands.
Journal of Applied Ecology, 35, 365–377.
Portier, C., Festa-Bianchet, M., Gaillard, J.M., Jorgenson, J.T.
& Yoccoz, N.G. (1998) Effects of density and weather on
survival of bighorn sheep lambs (Ovis canadensis). Journal
of Zoology, 245, 271–278.
Post, E. & Stenseth, N.C. (1998) Large-scale climatic fluctua-
tion and population dynamics of moose and white-tailed
deer. Journal of Animal Ecology, 67, 537–543.
Prins, H.H.T., Grootenhuis, J.G. & Dolan, T.T. (2000) Wild-
life Conservation by Sustainable Use. Conservation Biology
Series. Kluwer Academic Publishers, Boston, MA.
Putman, R.J. & Moore, N.P. (1998) Impact of deer in lowland
Britain on agriculture, forestry and conservation habitats.
Mammal Review, 28, 141–164.
Ramsay, P. (1997) Revival of the Land: Creag Meagaidh
National Nature Reserve. Scottish Natural Heritage, Perth,
UK.
Ratcliffe, P.R. (1987) The Management of Red Deer in Upland
Forests. Forestry Commission Bulletin 71. HMSO, London,
UK.
Rea, R.V. (2003) Modifying roadside vegetation management
practices to reduce vehicular collisions with moose Alces
alces. Wildlife Biology, 9, 81–91.
Reichman, O.J., Benedix, J.H. Jr & Seastedt, T.R. (1993)
Distinct animal-generated edge effects in a tallgrass prairie
community. Ecology, 74, 1281–1285.
1031
Management of
wild large
herbivores
© 2004 British
Ecological Society,
Journal of Applied
Ecology, 41,
1021–1031
Reynolds, P. & Staines, B. (1997) Deer management in
Scotland. Conservation and the Use of Wildlife Resources
(ed. M. Bolton), pp. 171–190. Chapman & Hall, London, UK.
Rietkerk, M., Ketner, P., Burger, J., Hoorens, B. & Olff, H.
(2000) Multiscale soil and vegetation patchiness along a
gradient of herbivore impact in a semi-arid grazing system
in West Africa. Plant Ecology, 148, 207–224.
Ritchie, M.E. & Olff, H. (1999) Spatial scaling laws yield a
synthetic theory of biodiversity. Nature, 400, 557–560.
Roosevelt, T. (1910) African Game Trails; An Account of the
African Wanderings of an American Hunter-Naturalist.
Scribner’s, New York, NY.
Rouget, C., Dumont, B. & Prache, S. (1998) Selection and use
of feeding sites and feeding stations by herbivores: a review.
Productions Animales, 11, 273– 284.
Ryerson, D.E. & Parmenter, R.R. (2001) Vegetation change
following removal of keystone herbivores from desert
grasslands in New Mexico. Journal of Vegetation Science,
12, 167–180.
Saether, B.E. (1997) Environmental stochasticity and popula-
tion dynamics of large herbivores: a search for mechanisms.
Trends in Ecology and Evolution, 12, 143–149.
Schaefer, O.J.A. & Messier, F. (1995) Habitat selection as a
hierarchy: the spatial scales of winter foraging by muskoxen.
Ecography, 18, 333–344.
Senft, R.L., Coughenour, M.B., Bailey, D.W., Rittenhouse,
L.R., Sala, O.E. & Swift, D.M. (1987) Large herbivore forag-
ing and ecological hierarchies. Bioscience, 37, 789–799.
Sharp, R. (2002) Saiga antelope facing catastrophe. Oryx, 36,
323–323.
Sheail, J. (1985) Pesticides and Nature Conservation: The British
Experience 1950– 1975. Clarendon Press, Oxford, UK.
Sheail, J. (1987) Seventy-Five Years in Ecology. The British
Ecological Society. Blackwell Scientific Publications, Oxford,
UK.
Sibbald, A.M. & Gordon, I.J. (2001) Tracking Animals with
GPS. Macaulay Land Use Research Institute, Aberdeen,
UK.
Sibbald, A.M., Hooper, R.J. & Gordon, I.J. (2001) Using
GPS to study the effects of human disturbance on the
behaviour of red deer stags on a highland estate in Scotland.
Tracking Animals with GPS (eds A.M. Sibbald & I.J. Gor-
don), pp. 39–43. Macaulay Land Use Research Institute,
Aberdeen, UK.
Sinclair, A.R.E. (1977) The African Buffalo; A Study of
Resource Limitation of Populations. University of Chicago
Press, Chicago, IL.
Smith, B.L. & Anderson, S.H. (1998) Juvenile survival and
population regulation of the Jackson elk herd. Journal of
Wildlife Management, 62, 1036–1045.
Smithers, R.H.N. (1983) The Mammals of the Southern African
Sub-Region. University of Pretoria Press, Pretoria, South
Africa.
Solberg, E.J., Loison, A., Ringsby, T.H., Saether, B.E. &
Heim, M. (2002) Biased adult sex ratio can affect fecundity
in primiparous moose Alces alces. Wildlife Biology, 8, 117 –128.
Solberg, E.J., Sæther, B.E., Strand, O. & Loison, A. (1999)
Dynamics of a harvested moose population in a variable
environment. Journal of Animal Ecology, 68, 186 –204.
Spalton, J.A., Lawrence, M.W. & Brend, S.A. (1999) Arabian
oryx reintroduction in Oman: successes and setbacks.
Oryx, 33, 168–175.
Stalmans, M.E., Witkowski, E.T.F. & Balkwill, K. (2002)
Evaluating the ecological relevance of habitat maps for wild
herbivores. Journal of Range Management, 55, 127–134.
Stanley Price, M.R. (1989) Animal Reintroductions: The
Arabian Oryx in Oman. Cambridge University Press,
Cambridge, UK.
Stinchcombe, J., Moyle, L.C., Hudgens, B.R., Loch, P.L.,
Chinnadurai, S. & Morris, W.F. (2002) The influence of the
academic conservation biology literature on endangered
species recovery planning. Conservation Ecology, 6, 15.
Stohlgren, T.J., Schell, L.D. & van den Heuvel, B. (1999) How
grazing and soil quality affect native and exotic plant diver-
sity in rocky mountain grasslands. Ecological Applications,
9, 45–64.
Sutherland, W.J. (2000) The Conservation Handbook.
Research, Management and Policy. Blackwell Science Ltd,
Oxford, UK.
Tainton, N.M., Morris, C.D. & Hardy, M.B. (1996) Complexity
and stability in grazing systems. The Ecology and Manage-
ment of Grazing Systems (eds J. Hodgson & A.W. Illius),
pp. 275–300. CAB International, Wallingford, UK.
Teer, J.G., Neronov, V.M., Zhirnov, L.V. & Blizniuk, A.I. (1996)
Status and exploitation of the saiga antelope in Kalmykia.
The Exploitation of Mammal Populations (eds V.J. Taylor &
N. Dunstone), pp. 75–87. Chapman & Hall, London, UK.
Terry, E.L., Mclellan, B.N. & Watts, G.S. (2000) Winter
habitat ecology of mountain caribou in relation to forest
management. Journal of Applied Ecology, 37, 589–602.
Thompson, D.B.A., Hester, A.J. & Usher, M.B. (1995) Heaths
and Moorland: Cultural Landscapes. HMSO, Edinburgh,
UK.
du Toit, J.T., Walker, B.H. & Campbell, B.M. (2004) Conserv-
ing tropical nature: current challenges for ecologists. Trends
in Ecology and Evolution, 19, 12–17.
Tow ers, W., Hall, J., Hester, A.J. & Malcolm, A. (2004) The
potential for native woodland in Scotland: the native wood-
land model. Scottish Natural Heritage, Battleby, UK.
van der Waal, C. & Dekker, B. (2000) Game ranching in the
Northern Province of South Africa. South African Journal
of Wildlife Research, 30, 151–156.
Wallis de Vries, M.F. (1996) Effects of resource distribu-
tion patterns on ungulate foraging behaviour. A modelling
approach. Forest Ecology and Management, 88, 167–177.
Wallis de Vries, M.F., Bakker, J.P. & van Wieren, S.E. (1998)
Grazing and Conservation Management. Conservation Biol-
ogy Series. Kluwer Academic Publishers, Dordrecht, the
Netherlands.
Welch, D. (1984) Studies in the grazing of heather moorland
in Northeast Scotland. I. Sites descriptions and patterns of
utilization. Journal of Applied Ecology, 21, 179–195.
Williamson, L.L. & Doster, G.L. (1981) Socio-economic
aspects of white-tailed deer disease. Diseases and Parasites
of White-Tailed Deer (ed. W.R. Davidson), pp. 434–439.
Tall Timbers Research Station, Tallahassee, FL.
Received 14 March 2003; final copy received 7 September 2004
... A key advantage of shooting is its specificity, which enables practitioners to target individuals or cohorts within the population (such as senescents, females or diseased individuals), that disproportionally contribute to ecological impacts or may be important for maintaining population health [10,75]. In contrast, poisoning and capture (trapping and snaring) are less discriminate and so are typically only legally permitted for use on non-native invasive species. ...
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Introduction: Over recent decades, the abundance and geographic ranges of wild ungulate species have expanded in many parts of Europe, including the UK. Populations are managed to mitigate their ecological impacts using interventions, such as shooting, fencing and administering contraception. Predicting how target species will respond to interventions is critical for developing sustainable, effective and efficient management strategies. However, the quantity and quality of evidence of the effects of interventions on ungulate species is unclear. To address this, we systematically mapped research on the effects of population management on wild ungulate species resident in the UK. Methods: We searched four bibliographic databases, Google Scholar and nine organisational websites using search terms tested with a library of 30 relevant articles. Worldwide published peer-reviewed articles were considered, supplemented by 'grey' literature from UK-based sources. Three reviewers identified and screened articles for eligibility at title, abstract and full-text levels, based on predefined criteria. Data and metadata were extracted and summarised in a narrative synthesis supported by structured graphical matrices. Results: A total of 123 articles were included in the systematic map. Lethal interventions were better represented (85%, n = 105) than non-lethal interventions (25%, n = 25). Outcomes related to demography and behaviour were reported in 95% of articles (n = 117), whereas effects on health, physiology and morphology were studied in only 11% of articles (n = 14). Well-studied species included wild pigs (n = 58), red deer (n = 28) and roe deer (n = 23). Conclusions: Evidence for the effects of population management on wild ungulate species is growing but currently limited and unevenly distributed across intervention types, outcomes and species. Priorities for primary research include: species responses to non-lethal interventions, the side-effects of shooting and studies on sika deer and Chinese muntjac. Shooting is the only intervention for which sufficient evidence exists for systematic review or meta-analysis.
... Changes in climate, plant biomass, and phenology over time are not consistent across space, precipitating changes in herbivore populations that also vary over space (Gordon et al. 2004;Zhao et al. 2019). Thus, analyses of large-scale plant-herbivore systems require the incorporation of spatial information (Mårell et al. 2006;Ndegwa Mundia and Murayama 2009;Serneels and Lambin 2001). ...
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Global temperatures are increasing, affecting timing and availability of vegetation along with relationships between plants and their consumers. We examined the effect of population density, herd body condition in the previous year, elevation, plant productivity and phenology, snow, and winter onset on juvenile body mass in 63 semi-domesticated populations of Rangifer tarandus throughout Norway using spatiotemporal generalized additive models (GAMs) and varying coefficient models (VCMs). Optimal climate windows were calculated at both the regional and national level using a novel nonlinear climate window algorithm optimized for prediction. Spatial and temporal variation in effects of population and environmental predictors were considered using a model including covariates decomposed into spatial, temporal, and residual components. The performance of this decomposed model was compared to spatiotemporal GAMs and VCMs. The decomposed model provided the best fit and lowest prediction errors. A positive effect of herd body condition in the previous year explained most of the deviance in calf body mass, followed by a more complex effect of population density. A negative effect of timing of spring and positive effect of winter onset on juvenile body mass suggested that a snow free season was positive for juvenile body mass growth. Our findings suggest early spring onset and later winter permanent snow cover as reinforcers of early-life conditions which support more robust reindeer populations. Our methodological improvements for climate window analyses and effect size measures for decomposed variables provide important contributions to account for, measure, and interpret nonlinear relationships between climate and animal populations at large scales.
... Our work highlights the importance of considering the effect of varying age-structure on population dynamics, suggests minimum combinations of vital rates required for increasing or decreasing elk population growth rates to general management objectives, and provides the framework required for future management-specific recommendations using stochastic population projection matrices. (Persson 2003, Parsons et al. 2013, and the substantial economic and cultural benefits derived from their exploitation (Gordon et al. 2004, Peterson et al. 2011, understanding the limiting and regulatory factors associated with elk population dynamics has received considerable attention (Raithel et al. 2007, Eacker et al. 2016. ...
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The dynamics of ungulate populations across variable ecosystems and management strategies demonstrate disparate trajectories such that some populations are overabundant, while other populations are subject to recovery efforts. Understanding how variation in vital rates such as pregnancy and survival integrate to shape the trajectories of populations is, therefore, helpful for informed management, particularly given that our understanding of the dynamics of harvested ungulate populations is often limited. Age‐related variation in vital rates among elk (Cervus canadensis) suggest that suitable population matrix models require age‐specific vital rates that can be logistically and analytically challenging to obtain. Our goals were to use a large, long‐term data set on elk and hierarchical Bayesian models to estimate age‐specific pregnancy and annual survival rates and their process variances, use stochastic population projection matrices to understand the effects of additional mortality from harvest on population dynamics, and identify the influence of different combinations of vital rates on population trajectories. We found that median age‐specific pregnancy rates increased with age from yearlings (0.52, 90% credible interval [CrI] = 0.37, 0.65) to a plateau among prime ages (e.g., 9‐year‐old: 0.91, 90% CrI = 0.87, 0.94), followed by a decline for the oldest ages (e.g., 19‐year‐old: 0.10, 90% CrI = 0.03, 0.28). Annual survival rates plateaued among prime‐aged animals (e.g., 9‐year‐old: 0.94, 90% CrI = 0.92, 0.96), and declined for the oldest‐ages (e.g., 19‐year‐old: 0.21, 90% CrI = 0.04, 0.56). We found higher process variation in pregnancy rates than survival rates; annual pregnancy rates for a 7‐year‐old varied from 0.82 (90% CrI = 0.67, 0.92) to 0.98 (90% CrI = 0.95, 0.99), and annual survival rates varied from 0.94 (90% CrI = 0.85, 0.96) to 0.96 (90% CrI = 0.93, 0.99). Simulated population trajectories indicated that additional mortality due to harvest resulted in a shift in the age structure towards younger animals with lower probabilities of pregnancy. When we held calf survival between 0.48 and 0.50 and specified constant pregnancy rates, changes in age structure alone resulted in variation of the recruitment of female calves from 0.20 to 0.16. We found that populations with a low mean value of calf survival (0.25) and no additional mortality due to harvest had marginal demographic performance ( λ geo ¯ = 1.02) and could sustain no additional mortality from harvest and still increase. In contrast, productive populations with a high mean value of calf survival (0.75) required high harvests to abate population growth (e.g., harvest rate = 0.20, λ geo ¯ = 0.94). Finally, we found a temporally lagged effect of harvest on age structure such that a shift towards younger animals could persist for multiple years following a reduction in harvest, suggesting that harvest may have multi‐year lagged depressive effects on population growth rates above and beyond the direct effects on survival rates. Our work highlights the importance of considering the effect of varying age‐structure on population dynamics, suggests minimum combinations of vital rates required for increasing or decreasing elk population growth rates to general management objectives, and provides the framework required for future management‐specific recommendations using stochastic population projection matrices. We found evidence for age‐related variation in elk pregnancy and survival rates. Our results suggest that additional mortality due to harvest shifts the age structure towards generally less‐productive younger elk and provide guidelines for the combinations of calf survival and harvest required to achieve population recovery or reduction goals.
... Ungulates such as rusa deer are known as ecosystem engineers, since they maintain the heterogeneity of landscapes, but when they are introduced into regions where they become invasive, they can adversely affect local biodiversity (Gordon et al., 2004;Davis et al., 2016). For instance, in New Zealand (Allen et al., 1984), Australia (Keith & Pellow, 2005) and south-western PNG (Bowe et al., 2007) the vegetation structure has been substantially altered by browsing of rusa deer. ...
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Abstract The rusa deer has been introduced to Merauke region and later to Vogelkop Peninsula in Indonesian New Guinea (West Papua) in 1928. It has widely dispersed across much of the West Papuan lowlands, but little is known on population size and its role for the livelihoods of rural communities. Here, our aim was to assess the population status of rusa deer, and to investigate the extent of hunting practices on this mammal in West Papua. We conducted camera trapping and line transect surveys simultaneously to estimate rusa deer population abundance in the Kwoor basin of the Tambrauw regency, Papua Barat province, Indonesia. We also interviewed hunters (n = 134), informants (n = 9) and households (n = 91) to assess hunting patterns and socioeconomic importance of rusa deer across 15 districts of the Tambrauw regency. We estimated rusa deer density within a 48‐km2 forested area at 10.34 (5.36–19.98) and 21.04 individuals/km2 using line transect and N‐mixture modelling approach using camera trapping data, respectively. Both density estimates are considerably higher than those from its native range in Java and Bali (0.08 individual/km2). Almost 92% of hunters reported that they hunted rusa deer in their traditional forests, being the most frequent amongst the 18 hunted species, particularly for commercial (62%) and subsistence (38%) purposes. Our results suggest that traditional hunting has become a significant livelihood activity and important income source in the study area. It is therefore imperative to identify potential management strategies on wildlife hunting while also considering that the high densities of introduced rusa deer may potentially exert adverse effects on native flora and fauna. This study further suggests that traditional knowledge (locally called ‘sasi’ system) and wildlife taboos still govern wildlife hunting and utilization of forest resources in West Papua, and these need to play a role in integrated community‐based wildlife management.
... The administrative boundaries used in wildlife management are as much a product of political and social influence as they are defined by knowledge of ecological processes (Meisingset et al. 2018). If management units do not closely match the distribution of a population, immigration and emigration 96 between units can impact the effectiveness of management decisions (Gordon et al. 2004, Limiñana et al. 2012. For example, the regulation of harvested populations is often determined at regional scales, where agencies make local management decisions based on the distribution of populations across a defined area (Williams et al. 1999, Robinson et al. 2016). ...
Article
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Wild turkeys are a wide-ranging species with considerable cultural and economic significance. As they can exist across a variety of ecosystems, understanding how land use affects population vital rates can be a crucial component of informed population management. This is even more important for turkey populations in Maine, where harsh winters can have negative impacts on survival and reproduction. I used a combination of banding and tracking data to better understand the relationship between turkey population ecology at their northern range limit and the diverse landscape gradient they occupy in Maine. I produced wildlife management district specific estimates of turkey abundance that accounted for spatial variation in harvest rate. I examined how turkeys moderated their movement behavior and resource selection according to weather factors during the winter. I expanded on traditional methods used to assess nesting habitat to produce a holistic estimate of turkey nesting habitat quality that accounted for multiple nesting stages and spatial scales. Finally, I simulated movement of turkeys during their seasonal movements between winter and spring to better understand how turkey populations were connected across the state. Turkey populations in Maine appear to be largely stable over the past decade, with populations being most dense in the southern portion of Maine and becoming increasingly less dense farther north and inland. Turkeys during the winter adjust their movement behavior, which was associated with changes in resource selection, in response to increased snow depths and decreased wind chill. Such changes likely allow turkeys to shelter and reserve energy during periods of severe winter weather. During the spring, turkeys depart their winter ranges and establish nesting ranges according to large-scale landscape characteristics. Resource selection changed throughout the nesting period according to the specific behavioral phase a turkey was in, with turkeys interacting with their environment at increasingly finer scales as movement became more localized. Finally, we expect that a considerable number of turkeys move among wildlife management districts during seasonal movements between winter and spring ranges, which warrants consideration for management and monitoring efforts.
... Globally, hunting of wildlife is a major and geographically widespread activity (Gordon et al. 2004, Fischer et al. 2013. Hunting provides important services to society, and also controls disservices produced by wildlife (Apollonio et al. 2010). ...
Article
Hunting is a widespread but often overlooked land-use activity, providing major benefits to society. Hunting takes place in most landscapes, yet it remains unclear which types of landscapes foster or dampen hunting-related services, and how hunting relates to other land uses. A better understanding of these relationships is key for sustainable land-use planning that integrates wildlife management. This is particularly urgent for Europe, where wildlife populations are increasing. Focusing on Sweden, we explored the spatial associations among hunting, agriculture, and forestry to identify archetypical combinations of these land uses. Specifically, we combined indicators on the extent and intensity of agriculture and forestry, with data on hunting bags for 63 game species using self-organizing maps, a non-parametric clustering approach. We identified 15 typical bundles of co-occurring land uses at the municipality level across Sweden. The harvest of forest grouse, bears, and moose co-occurred with forestry in northern Sweden, whereas the harvest of small game, different deer species, and wild boar co-occurred with agriculture across southern Sweden, reflecting species' biology, environmental factors, and management. Our findings also highlight the strength of associations among hunting and other land uses. Importantly, we identified large areas in central Sweden where harvest of game was below average, possibly indicating that intensity of hunting is out of balance with that of agriculture or forestry, potentially fostering conflict between wildlife and land use. Collectively, our results suggest that (1) hunting should be considered a major land use that, in Sweden, is more widespread than agriculture and forestry; (2) land-use planning must therefore integrate wildlife management; and (3) such an integration should occur in a regionalized manner that considers social-ecological context. Our approach identifies a first spatial template within which such context-specific land-use planning, aiming at aligning wildlife and diverse land uses, can take place.
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Deer are key components of many ecosystems and estimating deer abundance or density is critical to understanding these roles. Many field methods have been used to estimate deer abundance and density, but the factors determining where, when, and why a method was used, and its usefulness, have not been investigated. We systematically reviewed journal articles published during 2004–2018 to evaluate spatio‐temporal trends in study objectives, methodologies, and deer abundance and density estimates, and determine how they varied with biophysical and anthropogenic attributes. We also reviewed the precision and bias of deer abundance estimation methods. We found 3,870 deer abundance and density estimates. Most estimates (58%) were for white‐tailed deer (Odocoileus virginianus), red deer (Cervus elaphus), and roe deer (Capreolus capreolus). The 6 key methods used to estimate abundance and density were pedestrian sign (track or fecal) counts, pedestrian direct counts, vehicular direct counts, aerial direct counts, motion‐sensitive cameras, and harvest data. There were regional differences in the use of these methods, but a general pattern was a temporal shift from using harvest data, pedestrian direct counts, and aerial direct counts to using pedestrian sign counts and motion‐sensitive cameras. Only 32% of estimates were accompanied by a measure of precision. The most precise estimates were from vehicular spotlight counts and from capture–recapture analysis of images from motion‐sensitive cameras. For aerial direct counts, capture–recapture methods provided the most precise estimates. Bias was robustly assessed in only 16 studies. Most abundance estimates were negatively biased, but capture–recapture methods were the least biased. The usefulness of deer abundance and density estimates would be substantially improved by 1) reporting key methodological details, 2) robustly assessing bias, 3) reporting the precision of estimates, 4) using methods that increase and estimate detection probability, and 5) staying up to date on new methods. The automation of image analysis using machine learning should increase the accuracy and precision of abundance estimates from direct aerial counts (visible and thermal infrared, including from unmanned aerial vehicles [drones]) and motion‐sensitive cameras, and substantially reduce the time and cost burdens of manual image analysis. A minority of deer abundance and density estimates were accompanied by a measure of precision, and bias was seldom evaluated. The usefulness of deer abundance and density estimates would be substantially improved by reporting key methodological details, robustly assessing bias, using methods that increase detection probability, and reporting the precision of estimates.
Article
Wild ungulates are of fundamental importance for balancing ecosystems, as well as being the species of economic interest. Increasing concern over the accelerated population reduction of these species has resulted in the development of assisted reproduction techniques, such as in vitro fertilization (IVF), as a tool for conservation and multiplication. In the present scenario, IVF protocols were developed based on the methodologies used for domestic ungulates. Nevertheless, owing to the physiological and reproductive differences among the species, several factors associated with IVF and its relationship with the characteristics of the species of interest require clarification. In vitro conditions for the collection and selection of female and male gametes, oocyte maturation, sperm capacitation, co-incubation of gametes, and embryonic development can influence IVF results. Therefore, the present review considers the main advances in the methodologies already used for wild ungulates, emphasizing the strategies for improving the protocols to obtain better efficiency rates. Additionally, we discuss the conditions of each IVF stage, with emphasis on aspects related to in vitro manipulation and comparability with the protocols for domestic ungulates.
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p>Abandonment of agricultural land is widespread in many parts of the world, leading to shrub and tree encroachment. The increase of flammable plant biomass, that is, fuel load, increases the risk and intensity of wildfires. Fuel reduction by herbivores is a promising management strategy to avoid fuel build-up and mitigate wildfires. However, their effectiveness in mitigating wildfire damage may depend on a range of factors, including herbivore type, population density and feeding patterns. Here, we review the evidence on whether management with herbivores can reduce fuel load and mitigate wildfires, and if so, how to identify suitable management that can achieve fire mitigation objectives while providing other ecosystem services. We systematically reviewed studies that investigated links between herbivores, fire hazard, fire frequency and fire damage. We found that, in general, herbivores reduce fuel load most effectively when they are mixed feeders, when grazing and browsing herbivores are combined and when herbivore food preferences match the local vegetation. In some cases, the combination of herbivory with other management strategies, such as mechanical clearing, is necessary to reduce wildfire damage. Synthesis and Applications. We conclude that herbivores have the capacity to mitigate wildfire damage, and we provide guidance for grazing management for wildfire mitigation strategies. As areas undergoing land abandonment are particularly prone to wildfires, the maintenance or promotion of grazing by domestic or wild herbivores is a promising tool to reduce wildfire risk in a cost-effective way, while also providing other ecosystem services. Relevant land-use policies, including fire suppression policies, agricultural and forest(ry) policies could incentivise the use of herbivores for better wildfire prevention.</p
Book
One of the major challenges of sustainable development is the interdisciplinary nature of the issues involved. To this end, a team of conservation biologists, hunters, tourist operators, ranchers, wildlife and land managers, ecologists, veterinarians and economists was convened to discuss whether wildlife outside protected areas in Africa can be conserved in the face of agricultural expansion and human population growth. They reached the unequivocal - if controversial - conclusion that wildlife can be an economic asset, especially in the African savannas, if this wildlife can be sustainably utilized through safari hunting and tourism. Using the African savannas as an example, Wildlife Conservation by Sustainable Use shows that in many instances sustainable wildlife utilization comprises an even better form of land use than livestock keeping. Even when population pressure is high, as in agricultural areas or in humid zones, and wild animal species can pose a serious cost to agriculture, these costs are mainly caused by small species with a low potential for safari hunting. Although ranching has a very low rate of return and is hardly ever profitable, the biggest obstacle to the model of sustainable wildlife use outlined in Wildlife Conservation by Sustainable Use is from unfair competition from the agricultural sector, such as subsidies and lack of taxation, resulting in market distortion for wildlife utilization. This book thus gives valuable evidence for a different way of working, providing arguments for removing such distortions and thereby facilitating financially sound land use and making it a rationally sound choice to conserve wildlife outside protected areas. The expert team of authors, most of whom came together at a workshop to thrash out the ideas that were then developed into the various chapters, has written a superb account of recent research on this complex subject, resulting in a book that is a major contribution to our understanding of sustainable use of land. The important conclusion is that wildlife conservation can be possible for landholders and local communities if they have a financial interest in protecting wildlife on their lands.
Chapter
As a wildlife resource, the red deer (Cervus elaphus) population in Scotland is of considerable ecological, utilitarian and aesthetic importance. Scotland’s largest native herbivore, red deer, alone or in combination with domestic stock, can drive vegetation successions in the uplands. For example, where browsing is sufficiently intense, woodland is converted to open grass or dwarf-shrub dominated habitats. Therefore, red deer have profound implications for vegetation and associated animal communities.
Chapter
From a population of over 750 000 in 1958, the number of saiga antelope in the northwestern Caspian region of the Autonomous Republic of Kalmykia, Russian Federation, is now about 160 000. The range of the species has been reduced from over 120 000 km2 to about 20 000 km2. Intensive grazing, principally by sheep and also by cattle, and attempts to farm chernozemic (black) soils are major causes of habitat loss. Overgrazing has resulted in severe degradation of carrying capacity of the habitats for both livestock and saiga antelope. Over 20% of the semi-arid steppe habitat is desert and of little value to herbivores. In recent months poaching for horns used in oriental medicines has become a serious factor in population loss and distortion of the sex ratio of adults. This distortion in Kalmykia has put reproduction of the species at an unknown risk. Irrigation canals emanating from the Volga River, roads, fences, power lines and other contrivances are also important in disruption of migration routes and mortality. Although hunting and other uses of this species in Kalmykia are now prohibited, the antelope is at serious risk and management must be implemented to restore it to former numbers and use. Local people must receive some benefits from saiga to ensure its future.