ArticlePDF Available

Unsustainable vs. Sustainable Hunting for Food in Gabon: Modeling Short- and Long-Term Gains and Losses

Authors:

Abstract and Figures

Today, rural people continue to consume wild animals (aquatic and terrestrial) because they are often cheaper and more available than farmed livestock and fish. In many places where the meat from wild animals is an important source of food and income for poor rural families, the capture, consumption or trade of wild animals is illegal and remains within the informal sector and outside of national accounting and regulatory systems. Few studies exist to help policy makers and wildlife managers develop and implement systems designed to halt unsustainable hunting, prevent species loss, and maintain, over the long term, flows of wildlife available to people as a source of food and income. This paper uses empirical data from a tropical forest area in Gabon within a heuristic simulation model to explore how hunter capture rates would need to change over time to halt unsustainable hunting and to maximize the nutritional and economic value of wildlife as a source of food and income over the long term. Results show that sustainable hunting of wildlife populations that are at or near 50% of carrying capacity (0.5 K) generates more biomass available for consumption and income generation over 25 years than either hunting to maintain current population densities or continuing to hunt unsustainably. Unsustainable hunting generates more biomass than sustainable hunting but only for the first 1 to 3 years after which offtake dwindles rapidly. Achieving sustainable hunting will require that hunters reduce their offtake for 3–13 years until depleted populations recover, which may be unlikely unless they have access to alternative sources of food and income.
Content may be subject to copyright.
ORIGINAL RESEARCH
published: 24 September 2019
doi: 10.3389/fevo.2019.00357
Frontiers in Ecology and Evolution | www.frontiersin.org 1September 2019 | Volume 7 | Article 357
Edited by:
Krithi K. Karanth,
Wildlife Conservation Society, India
Reviewed by:
Zuzana Burivalova,
Princeton University, United States
Nathalie Van Vliet,
Center for International Forestry
Research, Indonesia
*Correspondence:
David S. Wilkie
dwilkie@wcs.org
Specialty section:
This article was submitted to
Conservation,
a section of the journal
Frontiers in Ecology and Evolution
Received: 19 October 2018
Accepted: 09 September 2019
Published: 24 September 2019
Citation:
Wilkie DS, Wieland M and Poulsen JR
(2019) Unsustainable vs. Sustainable
Hunting for Food in Gabon: Modeling
Short- and Long-Term Gains and
Losses. Front. Ecol. Evol. 7:357.
doi: 10.3389/fevo.2019.00357
Unsustainable vs. Sustainable
Hunting for Food in Gabon: Modeling
Short- and Long-Term Gains and
Losses
David S. Wilkie 1
*, Michelle Wieland 2and John R. Poulsen 3
1Global Conservation Program, Wildlife Conservation Society, Bronx, NY, United States, 2Africa Program, Wildlife
Conservation Society, Bronx, NY, United States, 3Nicholas School of the Environment, Duke University, Durham, NC,
United States
Today, rural people continue to consume wild animals (aquatic and terrestrial) because
they are often cheaper and more available than farmed livestock and fish. In many places
where the meat from wild animals is an important source of food and income for poor
rural families, the capture, consumption or trade of wild animals is illegal and remains
within the informal sector and outside of national accounting and regulatory systems. Few
studies exist to help policy makers and wildlife managers develop and implement systems
designed to halt unsustainable hunting, prevent species loss, and maintain, over the long
term, flows of wildlife available to people as a source of food and income. This paper uses
empirical data from a tropical forest area in Gabon within a heuristic simulation model to
explore how hunter capture rates would need to change over time to halt unsustainable
hunting and to maximize the nutritional and economic value of wildlife as a source of
food and income over the long term. Results show that sustainable hunting of wildlife
populations that are at or near 50% of carrying capacity (0.5 K) generates more biomass
available for consumption and income generation over 25 years than either hunting to
maintain current population densities or continuing to hunt unsustainably. Unsustainable
hunting generates more biomass than sustainable hunting but only for the first 1 to 3
years after which offtake dwindles rapidly. Achieving sustainable hunting will require that
hunters reduce their offtake for 3–13 years until depleted populations recover, which may
be unlikely unless they have access to alternative sources of food and income.
Keywords: bushmeat, hunting, unsustainable, protein deficit, simulation
INTRODUCTION
Across the planet many forests, grasslands, rivers, lakes, and coastal waters are empty or being
emptied of their wildlife to meet growing human demand for animal-source foods. If demand
exceeds the capacity of a wildlife population to replace harvested individuals the population will
decline, potentially to local extinction.
The human population continues to grow by over 80 million people annually and is expected
to reach 8.6 billion by 2030 (Desa, 2015) – nearly nine times the human population in 1,800. Half
of the future increase in human population will be in Africa, and by 2030 one in every four people
will be African (Desa, 2015). We are increasingly becoming an urban species, and global economic
Wilkie et al. Unsustainable vs. Sustainable Hunting for Food
development and poverty alleviation is making most of
us wealthier, changing what we want and can afford to
eat (Bodirsky et al., 2015). This combination of growth,
urbanization, and wealth is driving up demand for animal-
source foods (Alexandratos and Bruinsma, 2012). In many
places, production of animal-source foods is not keeping
pace with growing demand, and hunting and fishing of wild
animals often increases to unsustainable levels to fill the gap
(Wilkie et al., 2011; Ripple et al., 2016).
If this situation continues unchanged, we risk the wide-spread
loss of aquatic and terrestrial biodiversity as hungry people eat
species after species to extinction (Ripple et al., 2016). Millions
of people, particularly poor people, will face a looming protein
deficit that will make child malnutrition and “failure to thrive” an
appalling norm (Golden et al., 2011). Loss of wildlife populations
used as food will change plant and animal species composition
and distribution within ecosystems (Poulsen et al., 2013; Trolliet
et al., 2019). As a consequence, food webs will be disrupted and
destabilized, decreasing ecosystem resilience to climate shocks
and risking a cascade of species extinctions.
Estimates of the current volume and value of wild caught
terrestrial and aquatic animals are encouraging many
governments and development assistance organizations to
promote policies that would legalize the trade in wildlife as
food and bring this largely informal, weakly regulated economy
into a more regulated marketplace. However, guiding policy
reform solely on the current dietary and financial value of
wildlife used as food fails to take into account that most wildlife
populations captured for food are being over-exploited, and thus
current capture rates are too high and cannot be sustained over
the long-term.
Few studies exist to help policy makers and wildlife managers
develop and implement systems designed to halt unsustainable
hunting, prevent species loss, and maintain, over the long term,
flows of wildlife as a source of food and income (Robinson
and Bennett, 2000b; Bennett et al., 2007). Studies that explore
the impact that different management decisions would likely
have on wildlife population status and annual productivity
are particularly lacking. Exploring different scenarios would
help determine the approaches for optimizing both species
conservation and maintenance of wildlife as a provisioning
ecosystem service delivering food and income to families.
This paper uses empirical estimates of the abundance of
hunted species in the forests of Gabon to simulate, over 25 years,
the impact of three different hunting management scenarios,
on wildlife populations, annual production of wildlife, and the
benefits wildlife confer to people as a source of food and
income. The three scenarios are: (1) reduction of hunting to
sustainable levels at current wildlife population densities; (2)
managing annual harvest levels (offtake) to move the hunted
wildlife population levels toward 50% of carrying capacity
(0.5 K) where annual production is greatest, enabling maximum
sustainable offtake; and, (3) business-as-usual (i.e., continuation
of unsustainable hunting).
We acknowledge that the model presented in this paper
is, like all models, a simplification of reality. But as the
statistician George Box so sagely noted “All models are wrong,
but some are useful” (Box, 1979). Our model is offered as a
heuristic device designed to explore the outcomes of different
approaches to managing hunting of wildlife for food and income.
Whether managers and policy makers: (a) should attempt to
halt unsustainable hunting through spatial closures, individual or
community quotas, exclusion of non-rights holders, or taxation
and (b) how they should assess what is or is not sustainable
offtake is beyond the scope of this paper.
MATERIALS AND METHODS
To explore what happens to the supply of wild meat as hunting
transitions from being unsustainable to sustainable, we will use
an example based on data reported from recent research in
5,807 km2of tropical moist forest around the town of Makokou,
Gabon (Koerner et al., 2017). The authors conducted surveys of
terrestrial and arboreal wildlife within three zones of increasing
distance from villages (0–6 km to 1,871 km2, 6–15 km to 2,126
km2, and >15 km to 1,830 km2).
For this hunting simulation we focus on three monkey
species (Cercopithecus mona pogonias—crested mona monkey,
C. n. nictitans—great white-nosed monkey, and Lophocebus
albigena—gray-cheeked mangabey), and small (Cephalophus
monticola—blue duiker) and medium-size duikers (C.
callipygus—peters duiker, C. leucogaster- white-bellied duiker,
and C. dorsalis castaneus—bay duiker). These were chosen
because Koerner et al. (2017) report estimates of their densities
(Table 1) and they are the most commonly hunted, traded and
consumed species when wildlife populations are not depleted
from overhunting (Abernethy et al., 2013). For each species or
species group (e.g., medium-sized duikers), we used density
data within each zone to calculate total abundance. To calculate
sustainable yield, H–the number of animals that can be taken
from a population of any size over an indefinite period without
depleting the stock, we used the standard Gordon-Schaefer
equation under the assumption of logistic population growth.
rSt(1 St/K) =Ht
The intrinsic rate of population growth (r) for each species was
drawn from the literature (Fa et al., 1995) or computed using
Cole’s equation (Cole, 1954). Several studies suggest that most
hunting in central Africa occurs within approximately 15 km of
settlements (Abernethy et al., 2013; Coad et al., 2013; Beirne
et al., 2019). Given this we assumed that the area further than
15 km from villages can serve as a largely unhunted reference
point where populations are close to or at carrying capacity
(K). Stis the stock (abundance) and Htthe sustainable yield
of a hunted species at time t. Because the annual population
growth rate (dS/dt) when plotted against population size (S)
is shaped like an inverted U (Figure 1), sustainable yield will
be the same when a population is near zero (say 0.01 K) or
near carrying capacity (say 0.99 K), and will be maximized
around 0.5 K (i.e., maximum sustainable yield—MSY) where a
population is growing at its fastest rate. We understand the
risks of harvesting a population at MSY (Reynolds et al., 2001)
Frontiers in Ecology and Evolution | www.frontiersin.org 2September 2019 | Volume 7 | Article 357
Wilkie et al. Unsustainable vs. Sustainable Hunting for Food
TABLE 1 | Intrinsic rate of increase, average adult body weight, and density of hunted primates and ungulates within the Makokou study area, Gabon.
Near <6km Intermediate 6–15 km Far >15 km
Species r Avg adult weight (kg) Density (#/km2)
Great white-nosed monkey (C. nictitans) 1.12 3.8 6.01 11.19 17.42
Crested mona monkey 1.12 3.6 4.54 8.13 13.17
Gray-cheeked mangabey 1.19 7.7 2.14 4.34 8.10
Medium- size duikers 1.54 16.0 1.20 2.67 7.33
Blue duiker 1.63 4.7 1.31 2.18 3.43
Data sources
r from Fa et al. (1995) and Cole (1954)
Avg adult weight from Kingdon et al. (2013)
Density from Koerner et al. (2017)
FIGURE 1 | The annual wildlife production curve, assuming logistic growth,
follows an inverted U shape with production maximized at 0.5 K.
and are not advocating this as a hunting management strategy.
Rather, we are simply using the concept in the model to estimate
the maximum sustainable offtake that is theoretically possible.
In reality, a more precautionary approach where offtake is set
less than MSY would reduce the risk of over-exploitation and
local extinction.
We simulated offtake over a 25-year period for three scenarios:
(1) sustainable hunting at current population densities; (2)
maximum sustainable yield when population levels were at 0.5 K;
and, (3) unsustainable business-as-usual hunting. Achieving
MSY requires that the initial population at t0grow or shrink
to 0.5 K. To allow a population to grow, offtake was set at 10,
25, or 50 percent below sustainable yield to leave a surplus to
increase Sin time t+1. If the initial population was above 0.5 K
offtake was increased to 10, 25, or 50 percent above sustainable
yield to deplete the population to 0.5 K. By manipulating offtake
to 10, 25, or 50 percent below or above sustainable yield, the
model is able to influence how rapidly the population level of each
hunted species reaches 0.5 K—the higher the percentage the more
quickly 0.5 K is obtained. For the business-as-usual scenario, we
set offtake 10, 25, or 50 percent above sustainable yield. For
all three scenarios, the abundance of each species within the
near (<6 km) and intermediate (6–15 km) zones at t0was set
using their empirically measured density (Koerner et al., 2017).
Abundance within the far zone (>15 km) at t0was set at 90%
of the empirical value (i.e., 0.9 K) so that the sustainable yield
calculation would be >0. We converted offtake of individuals
to biomass using average adult body weight from the literature
(Kingdon et al., 2013).
From meat consumption studies in Gabon (Starkey, 2004;
Wilkie et al., 2005; Foerster et al., 2012), we know that an
average individual (reported as an Adult Male Equivalent)
consumes 0.25 kg of wild meat per day in rural villages. This is
approximately 100% of daily protein requirements as specified by
the World Health Organization. Daily consumption of wild meat
declines to 0.12 kg/AME/day in provincial towns (like Makokou)
and 0.02 kg/AME/day in large cities (like Libreville). Using these
figures, we calculated how many consumers in villages, towns or
cities could be supplied, based on current consumption patterns,
with wild meat over time from unsustainable or sustainable
hunting within 6 and 15 km of settlements, and within the total
study area of 5,807 km2.
RESULTS
Assuming that wildlife populations in the largely unhunted area
>15 km from settlements are close to or at carrying capacity,
the Koerner et al. (2017) data suggest that the near zone wildlife
populations within 6 km from settlements are already over-
exploited averaging 0.3 K. The intermediate zone populations are
currently being hunted at 0.56 K (i.e., close to MSY). As expected
based on hunters’ preference for large bodied species, mid-size
duikers appear to be more heavily depleted than smaller bodied
species both in the near (0.16 vs. 0.38 K) and intermediate (0.36
vs. 0.64 K) zones (Table 1).
Within the near zone the abundance of all species populations
at t0are below 0.5 K. In the intermediate zone only mid-
size duiker abundance is below 0.5 K at t0. Given this, even
if hunters decided to hunt wildlife within the three zones to
maintain, permanently, their current abundance (i.e., scenario
1–sustainable yield) this would not maximize offtake over
a 25-year period, because wildlife densities are either above
or below 0.5 K (Figure 2). For example, the blue duiker
population is currently below 0.5 K at t0within the near
zone (0.38 K) and above 0.5 K within the intermediate zone
Frontiers in Ecology and Evolution | www.frontiersin.org 3September 2019 | Volume 7 | Article 357
Wilkie et al. Unsustainable vs. Sustainable Hunting for Food
FIGURE 2 | Three comparisons of annual offtake over 25 years: sustainable
yield (scenario 1); maximum sustainable yield (scenario 2); and
business-as-usual (scenario 3). (A) (H) 10% recovery to 0.5 K then MSY
compared to business-as-usual offtake 10% higher than sustainable yield; (B)
(H) 25% recovery to 0.5 K then MSY compared to business-as-usual offtake
25% higher than sustainable yield (C) (H) 50% recovery to 0.5 K then MSY
compared to business-as-usual offtake 50% higher than sustainable.
(0.64 K). If hunting was maintained at, or reduced to, sustainable
levels such that current population levels of blue duikers did
not change (scenario 1), hunting would generate 22% less
biomass over a 25-year period than would a management
system that increased or decreased the population to 0.5 K
and then allowed hunting at MSY. For all modeled species
combined, if hunting was to be managed at t0population
levels sustainable offtake would generate 26–30% less biomass
available for consumption or income generation than when
hunted at 0.5 K. So simply halting unsustainable hunting
at t0population levels would not be rational if hunters
maximize the rate of offtake following Charnov’s (1976) marginal
value theorem.
TABLE 2 | Estimated number of years that depleted wildlife populations within
6 km of villages in Gabon might take to recover to 0.5 K when offtake is reduced
by 10, 25, or 50%.
Time to recovery to 0.5K Years
Species (H)10% (H)25% (H)50%
Great white-nosed monkey 7 5 4
Crested mona monkey 8 5 4
Gray-cheeked mangabey 11 5 3
Medium- size duikers 13 7 5
Blue duiker 5 4 3
Average 9 5 4
The estimated time to population recovery to 0.5 K in the
near zone when offtake is reduced by 10, 20, and 50% below
sustainable yield takes on average 9, 4, and 3 years, respectively
(Table 2), with mid-sized duikers taking the longest time (13
years) to recover to 0.5 K.
Reducing offtake below sustainable yield within 6 km from
villages to allow depleted populations to recover to 0.5 K would
require that hunters leave (i.e., not hunt) 12,679 to 15,340 animals
in the forest (Table 3) during the recovery years (Table 2). As
recovery is faster when offtake is reduced 50% below sustainable
yield, the total number of animals not hunted is lower than
for a 25 or 10% reduction. Reducing hunting to allow recovery
of depleted wildlife populations would also reduce wild meat
biomass available for consumption by 97,019 to 120,551 kg.
Similarly income to all hunters combined (assuming they sell 50%
of their catch) would be reduced by $26,680 to $33,151 based on
an average sales price of $0.55/kg (Gally and Jeanmart, 1996).
Though this simulation only includes a subset of all wildlife
species hunted for food near Makokou, the simulated estimate of
103 kg/km2for MSY is within the lower range of estimates for
maximum sustainable production in tropical forests (Robinson
and Bennett, 2000a).
Hunting wildlife populations so that their abundance
recovered or declined to 0.5 K, and then hunting them at MSY
always generated a higher total biomass over 25 years than
sustainable yield scenario 1, and the unsustainable business-
as-usual scenario 3 (Figure 2). That said, for the first 2–3
years offtake in the business-as-usual scenario was higher than
sustainable yield (scenario 1), but dropped to 50% of MSY after
19 years when offtake is 10% higher than is sustainable, 9 years
when offtake is 25% higher than is sustainable, and 6 years when
offtake is 50% higher than is sustainable. Unsustainable offtake
falls to below 1% of MSY after 23 years when offtake is 25% higher
than is sustainable and 13 years when offtake is 50% higher than
is sustainable (Figure 2).
To calculate the Net Present Value of wildlife hunted for
food (i.e., the current value relative to future cash returns over
a given time period), we assigned a price of $1 per kg and
used a 20% discount rate, which is a realistic cost of capital
in Gabon (i.e., the price lenders charge borrowers). NPV was
higher for the business-as-usual scenario only during the first
5 years with a 10% unsustainable hunting rate. In all other
Frontiers in Ecology and Evolution | www.frontiersin.org 4September 2019 | Volume 7 | Article 357
Wilkie et al. Unsustainable vs. Sustainable Hunting for Food
TABLE 3 | Reduction in: (a) animals hunted; (b) biomass available for consumption or sale; and, (c) economic value to hunters when hunting of depleted wildlife within
6km of villages is reduced by 10, 25, or 50% below sustainable yield (H) to allow populations to recover to 0.5K.
Reduced offtake for recovery
to 0.5K
Number of individuals Biomass for consumption (kg) Value to hunters (US$) selling 50% of biomass
Species (H) 10% (H) 25% (H) 50% (H) 10% (H) 25% (H) 50% (H) 10% (H) 25% (H) 50%
Great white–nosed monkey 4,296 4,235 4,289 16,326 16,093 16,297 –$4,490 –$4,426 –$4,482
Crested mona monkey 3,247 3,201 3,240 11,690 11,522 11,664 –$3,215 –$3,169 –$3,207
Gray–cheeked mangabey 3,207 2,895 1,609 24,693 22,295 12,389 –$6,790 –$6,131 –$3,407
Medium– size duikers 4,095 3,857 3,542 65,516 61,710 56,669 –$18,017 –$16,970 –$15,584
Blue duiker 495 626 0 2,326 2,942 0 –$640 –$809 $0
Total 15,340 14,814 12,679 120,551 114,562 97,019 –$33,151 –$31,504 –$26,680
timeframes and unsustainable hunting rates, NPV was higher for
the MSY scenario.
Though sustainable hunting at current (t0) population levels
generates less biomass available for consumption than hunting
at MSY, it would produce enough wild meat for a village
population of 0.75 people/km2which is close to the global
estimate (Robinson and Bennett, 2000a; Peres and Nascimento,
2006) of the human carrying capacity of tropical forests in terms
of protein supply (i.e., 1 person/km2).
If the whole area is hunted at MSY (i.e., when all hunted
populations are at 0.5 K), the three primate and four ungulate
species could provide a sustainable supply of animal source
foods over a 25-year period to an average of: a) 6,185 people
in villages, covering 100% of daily protein requirements; or b)
13,402 people in provincial towns, meeting 46% of daily protein
requirements; or c) 80,411 people in large cities, meeting 8% of
daily protein requirements.
In contrast, when wildlife are being hunted unsustainably
(business-as-usual), over 25 years the 10% depletion scenario
supplied wild meat on average to only: (a) 3,755 people in villages;
or (b) 8,137 people in towns, or (c) 48,820 people in cities, and
the 50% depletion scenario supplied wild meat on average to: (a)
1,271 people in villages; or (b) 2,754 people in towns; or (c) 16,525
people in cities.
Unsustainable hunting (i.e., the 10, 25, and 50% business-as-
usual scenario) only increased the supply of wild meat to village,
town and city dwellers for the first 1 or 2 years with supply
plunging to <50% of the MSY scenario by years 6, 10 and 19 in
the 50, 25, and 10% unsustainable hunting scenarios, respectively.
DISCUSSION
In 1998, 40% of Central African forest was within 10 km of
a road (Abernethy et al., 2013). By 2017 that had increased
to 53% (Koerner et al., 2017). Of the 177 species that are
hunted in Central Africa (Taylor et al., 2015) for food, 97
are being hunted at unsustainable levels according to the
IUCN Red List. In this paper, we showed that populations of
commonly hunted species (3 primates and 4 ungulates) are likely
being hunted at unsustainable levels (i.e., population abundance
has fallen to an average of 0.3 K) in a zone within 6 km of
settlements, near Makokou in Gabon. Larger-bodied red duikers
appear to be unsustainably hunted (0.36 K) up to 15 km away
from settlements.
Establishing and enforcing rules to render hunting sustainable
at current wildlife population levels across all zones would:
(a) require hunters to substantially reduce their offtake for the
initial years when unsustainable hunting generates higher offtake
(Figure 2); and (b) generate approximately 20% less biomass than
managing wildlife populations at 0.5 K (scenario 2). Similarly,
allowing populations to reach 0.5 K so that they could be hunted
at MSY would require hunters to reduce offtake by as much
as 282,166 kg over 2 to 3 years or until wildlife populations
recovered to 0.5 K. Persuading all hunters to reduce their offtake
even for a few years is unlikely unless they are compensated for
lost food and income. Legalizing hunting, only for hunters from
villages with legitimate historical claims to nearby forest, may
also not solve the problem if: (a) the majority of current hunters
have legitimate claims to hunt; and, (b) traditional hunting zones
do not extend beyond 15 km from villages, and thus are not under
the jurisdiction of legitimate village hunters.
The government of Gabon has on more than one occasion
voiced an interest in legalizing the trade in wildlife as food and
using the tax revenue to finance wildlife conservation both within
and outside of national parks and reserves. Results from this
study show that for depleted populations to recover offtake would
have to decrease substantially at least for a few years. As a result,
tax revenues from a legalized trade would see a comparable
decline during the recovery years, making it unlikely that taxes
would even cover the costs of tax collection, let alone increase
investment in wildlife law enforcement (Wilkie et al., 2006).
A shift from unsustainable to MSY hunting does initially
impose costs on hunters. But the alternative business-as-usual
scenario causes offtake to decline rapidly so that within 10 to
18 years, for the 50 and 25% unsustainable hunting scenarios,
wildlife populations have been effectively wiped out (Figure 2).
The Koerner et al. (2017) data as interpreted in this paper
show that wildlife populations in 32% of the study area (near zone
<6 km) have already been depleted to 0.3 K, and in 37% of the
area (intermediate zone 6–15 km) wildlife have been depleted to
0.56 K. The remaining 31% (>15 km from villages), we assume,
based on the reported paucity of human sign, to be only rarely
hunted and thus wildlife populations might be near carrying
capacity (i.e., 0.9 to 1.0 K). Taken together, this means that
Frontiers in Ecology and Evolution | www.frontiersin.org 5September 2019 | Volume 7 | Article 357
Wilkie et al. Unsustainable vs. Sustainable Hunting for Food
wildlife populations within 68% (i.e., >6 km from settlements) of
the study area near Makokou are still in relatively robust health
(i.e., they are near or above 0.5 K). This is maybe not surprising
as Gabon has a small human population (1.7 million–CIA World
Factbook) for its geographic area. Moreover, 89% of Gabonese
live in urban areas and 88% of the country is still covered in forest.
If the entire forest was depleted to the same level as the near
zone (i.e., 0.3 K), the forest might be emptied of wildlife in 5 to
10 years under current, unsustainable, hunting levels. Setting the
initial abundance of all 7 species at 0.1 K, leads to their extirpation
within 3–4 years. In many areas of central Africa, the forest is
already almost empty.
Even under the most optimistic scenario, where the near,
intermediate and far zones are all hunted at MSY, the forest
will only feed a small number of people. This means that
legalization of hunting is not a solution for the poor rural
families who depend on wildlife as their primary source of
dietary protein. Even if hunting was legalized everywhere within
50 km from settlements (5,807 km2– an area almost two
times the size of either the state of Rhode Island or the
country of Luxembourg) the maximum possible sustainable
offtake would feed 6,185 people. This number drops to 4,235
if hunting is limited to within 15 km of settlements, and to
1,930 if hunting is restricted to 6 km of settlements. With
human population growth in Gabon estimated at 1.92% in
2017 (CIA World Factbook), in 20 years the population will
have increased by more than 50%, with much of that growth
being in urban areas. That said, in the future, all other things
held constant, an even smaller percentage of the Gabonese
village population can expect to get their protein supply solely
from wildlife.
The situation in towns and cities is more complicated given
that wild meat is a rival good, and the meat eaten in villages is
no longer available to be consumed in towns and cities. Hunters
can either use wild meat to feed their extended families or barter
or sell some or all of it to purchase necessities or luxury items.
If, implausibly, all animals from all zones hunted at MSY were
traded to the nearest town and none were consumed in the
hunters’ villages, then 98% of the town of Makokou could get a
minority (46%) of their daily protein requirements from wildlife.
This is not only unrealistic, but the residents of Makokou would
still need to find 54% of their daily protein requirements from
other animal source foods.
The production of wildlife is limited by the availability of
high-quality habitat. In Gabon and across central Africa, wildlife
habitat is shrinking, not expanding, as forest lands are converted
to farms, plantations, mines, roads and settlements (Austin
et al., 2017; Kleinschroth et al., 2019). So, supply is either
optimistically likely to remain static at MSY (assuming we can
manage hunting sustainably) or, more realistically, will shrink as
non-hunting factors like habitat destruction begin to drive down
wildlife populations.
Rarely do Gabonese hunters trade more than 50% of the
animals they hunt (Coad, 2007; Table 5.1), but this could change
if consumers were willing to pay higher prices. If supply shrinks
and/or demand increases, we might expect the price to rise,
because there is evidence that demand for wild meat in Gabon
is relatively price inelastic (Wilkie et al., 2005; Foerster et al.,
2012) when substitutes are more expensive or unavailable. If price
rises, then hunters may be motivated to sell a greater portion of
the animals they capture. With less wild meat, levels of protein
and micro-nutrient deficiency and “failure to thrive” amongst
children will increase in wild meat-dependent villages (Golden
et al., 2011).
As the human population of Gabon continues to grow,
and as successful poverty alleviation efforts increase household
income, we expect demand for animal-source foods to increase
substantially (Wilkie et al., 2016) coupled with static or
declining wild meat availability. To avoid this looming protein
deficit and to prevent protein-hungry people from eating
wild animals to extinction, conservation organizations must
convince development organizations and donors to invest in
increasing the supply of sustainably produced animal-source
foods. Additionally, these investments should focus on feeding
growing provincial towns close to still relatively abundant wildlife
populations, and large metropolitan cities where per capita
demand for wild meat is small but the aggregate demand of
millions of consumers is huge.
Loss of wildlife from unsustainable hunting and fishing
will have irrevocable, long-term impacts on forest species
composition, distribution, productivity, and carbon content
(Poulsen et al., 2013). But this conservation crisis cannot solely be
solved with the classical conservation solution (i.e., establishing
and managing wildlife populations within state protected
areas and community reserves). Rather, to avoid this looming
protein deficit these provincial towns and metropolitan cities
must be able to develop profitable and sustainable enterprise
that can supply animal-source foods in sufficient quantity to
meet demand.
Thankfully these towns and cities are large enough to
support profitable private-sector livestock, farmed fish,
marketing, butchering, and veterinary-care enterprises. A
focus on family-scale, back-yard production of new, more
disease-resistant and productive breeds of poultry and other
small livestock (guinea pigs and rabbits), makes sense for
several reasons. Back yard production, minimizes capital
costs, helps empower women as they are often the small
livestock owners and producers, increases opportunities for
unemployed and under-employed youth, avoids the need for
cold chains (i.e., refrigerated supply chains), and is scalable as
additional back-yard producers adopt observably successful
innovations. Avoiding this looming protein deficit will not
only help conserve wildlife hunted for food, it will increase
household food and income security, reduce unemployment,
and might also reduce motivation for youth and whole
families to leave relatives and their homelands to seek a better
life elsewhere.
This paper shows that current levels of hunting of wildlife
for food and income risks fully depleting wildlife populations
within 6 km of settlements. Gabon’s growing human population
Frontiers in Ecology and Evolution | www.frontiersin.org 6September 2019 | Volume 7 | Article 357
Wilkie et al. Unsustainable vs. Sustainable Hunting for Food
will increase wild meat demand. Coupled with habitat loss
and a reduction in wildlife production, our model suggests
that current levels of hunting risk depleting wildlife across
the landscape. To transition from unsustainable to sustainable
hunting will require substantial reduction in hunting levels
to allow depleted wildlife populations to recover. During this
recovery period the supply of wildlife for food and income
will be significantly lower than it is currently. Hunters are
unlikely to willingly reduce the benefits they gain from
hunting at current levels, even if they are not sustainable
over the next 20 years. The government of Gabon and its
conservation partners will need to find ways to offset the
short-term losses of food and income until wildlife populations
recover, otherwise hunters will have little interest in complying
with sustainable hunting regulations and may take actions to
undermine them.
AUTHOR CONTRIBUTIONS
DW and MW contributed the initial concept. JP provided
the wildlife abundance data from Gabon. DW developed the
simulations. DW, MW, and JP contributed to the writing of
the paper.
FUNDING
The European Commission Directorate-General for
International Cooperation and Development (DG DEVCO)
and the United Nations Food and Agricultural Organization for
financial support to DW and MW. Duke University provided
funds to JP for field data collection.
ACKNOWLEDGMENTS
The authors would like to thank the Government of Gabon,
in particular the Center National de la Recherche Scientifique
et Technologique (CENAREST) and the Agence Nationale
des Parcs Nationaux (ANPN) for permission to collect field
data, and would like to thank Dr. Timothy O’Brien and Dr.
Samantha Strindberg for their comments on the concept and
a technical review of the simulation. We would also like
to thank the European Commission Directorate-General for
International Cooperation and Development (DG DEVCO)
and the United Nations Food and Agricultural Organization
for financial support to DW and MW. Field data collection
for this paper was supported by funds provided to JP from
Duke University.
REFERENCES
Abernethy, K. A., Coad, L., Taylor, G., Lee, M. E., and Maisels, F. (2013). Extent
and ecological consequences of hunting in Central African rainforests in the
twenty-first century. Philos. Trans. R. Soc. Lond. B Biol. Sci. 368:20120303.
doi: 10.1098/rstb.2012.0303
Alexandratos, N., and Bruinsma, J. (2012). “World agriculture towards 2030/2050:
the 2012 revision,” in ESA Working Paper No. 12–03 (Rome: FAO).
Austin, K. G., Lee, M. E., Clark, C., Forester, B. R., Urban, D. L., White, L., et
al. (2017). An assessment of high carbon stock and high conservation value
approaches to sustainable oil palm cultivation in Gabon. Environ. Res. Lett.
12:014005. doi: 10.1088/1748-9326/aa5437
Beirne, C., Meier, A. C., Mbele, A. E., Menie Menie, G., Froese, G., Okouyi,
J., et al. (2019). Participatory monitoring reveals village-centered gradients
of mammalian defaunation in central Africa. Biol. Conserv. 233, 228–238.
doi: 10.1016/j.biocon.2019.02.035
Bennett, E. L., Blencowe, E., Brandon, K., Brown, D., Burn, R. W., Cowlishaw,
G. U. Y., et al. (2007). Hunting for consensus: reconciling bushmeat harvest,
conservation, and development policy in west and central Africa. Conserv. Biol.
21, 884–887. doi: 10.1111/j.1523-1739.2006.00595.x
Bodirsky, B. L., Rolinski, S., Biewald, A., Weindl, I., Popp, A., and Lotze-Campen,
H. (2015). Global food demand scenarios for the 21st century. PLoS ONE
10:e0139201. doi: 10.1371/journal.pone.0139201
Box, G. E. (1979). All models are wrong, but some are useful. Robust. Stat. 202:549.
Charnov, E. L. (1976). Optimal foraging: attack strategy of a Mantid. Am. Natur.
110, 141–151. doi: 10.1086/283054
Coad, L., Schleicher, J., Milner-Gulland,E. J., Marthews, T. R., Starkey, M., Manica,
A., et al. (2013). Social and ecological change over a decade in a village
hunting system, central Gabon. Conserv. Biol. 27, 270–280. doi: 10.1111/cobi.
12012
Coad, L. M. (2007). Bushmeat hunting in Gabon: socio-economics and hunter
behavior (PhD thesis). University of Cambridge, Cambridge, United Kingdom.
Cole, L. C. (1954). The population consequences of life history phenomena. Quart.
Rev. Biol. 29, 103–137. doi: 10.1086/400074
Desa, U. (2015). World Population Prospects: The 2015 Revision, Key Findings and
Advance Tables. Working Paper No. ESA/P/WP.241.
Fa, J. E., Juste, J., Perez del Val, J., and Castroviejo, J. (1995). Impact of market
hunting on mammal species in Equatorial Guinea. Conserv. Biol. 9, 1107–1115.
doi: 10.1046/j.1523-1739.1995.951107.x
Foerster, S., Wilkie, D., Morelli, G., Demmer, J., Starkey, M., Telfer, P.,
et al. (2012). Determinants of bushmeat consumption among rural
households in Gabon, Central Africa. Conserv. Biol. 26, 335–344.
doi: 10.1111/j.1523-1739.2011.01802.x
Gally, M., and Jeanmart, P. (1996). Etude de la chasse villageoise en foret dense
humide d’Afrique centrale Faculté Universitaire des Sciences Agronomiques de
Gembloux.
Golden, C. D., Fernald, L. C. H., Brashares, J. S., Rasolofoniaina, B. J. R.,
and Kremen, C. (2011). Benefits of wildlife consumption to child nutrition
in a biodiversity hotspot. Proc. Natl. Acad. Sci. U.S.A. 108, 19653–19656.
doi: 10.1073/pnas.1112586108
Kingdon, J., Happold, D., Butynski, T., Hoffmann, M., Happold, M., and Kalina, J.
(2013). Mammals of Africa. London: Bloomsbury Natural History.
Kleinschroth, F., Laporte, N., Laurance, W. F., Goetz, S. J., and Ghazoul, J. (2019).
Road expansion and persistence in forests of the Congo Basin. Nat. Sustain. 2,
628–634. doi: 10.1038/s41893-019-0310-6
Koerner, S. E., Poulsen, J. R., Blanchard, E. J., Okouyi, J., and Clark, C. J. (2017).
Vertebrate community composition and diversity declines along a defaunation
gradient radiating from rural villages in Gabon. J. Appl. Ecol. 54, 805–814.
doi: 10.1111/1365-2664.12798
Peres, C., and Nascimento, H. (2006). Impact of game hunting by the
Kayapo of south-eastern Amazonia: implications for wildlife conservation
in tropical forest indigenous reserves. Biodivers. Conserv. 15, 2627–2653.
doi: 10.1007/s10531-005-5406-9
Poulsen, J. R., Clark, C. J., and Palmer, T. M. (2013). Ecological erosion of an
Afrotropical forest and potential consequences for tree recruitment and forest
biomass. Biol. Conserv. 163, 122–130. doi: 10.1016/j.biocon.2013.03.021
Reynolds, J. D., Mace, G. M., Redford, K. H., and Robinson, J. G. (2001).
Conservation of Exploited Species. Cambridge: Cambridge University Press; The
Wildlife Conservation Society; The Zoological Society of London.
Ripple, W. J., Abernethy, K., Betts, M. G., Chapron, G., Dirzo, R., Galetti, M., et al.
(2016). Bushmeat hunting and extinction risk to the world’s mammals. R. Soc.
Open Sci. 3:160498. doi: 10.1098/rsos.160498
Frontiers in Ecology and Evolution | www.frontiersin.org 7September 2019 | Volume 7 | Article 357
Wilkie et al. Unsustainable vs. Sustainable Hunting for Food
Robinson, J. G., and Bennett, E. L. (2000a). “Carrying capacity limits to sustainable
hunting in tropical forests,” in Hunting for Sustainability in Tropical Forests,
eds. J. G. Robinson and E. L. Bennett (New York, NY: Columbia University
Press), 13–30.
Robinson, J. G., and Bennett, E. L. (2000b). Hunting for Sustainability in Tropical
Forests. New York, NY: Columbia University Press.
Starkey, M. (2004). Commerce and subsistence: the hunting, sale and consumption
of bushmeat in Gabon (Ph.D. Dissertation). Cambridge University, Cambridge,
United Kingdom.
Taylor, G., Scharlemann, J. P. W., Rowcliffe, M., Kumpel, N., Harfoot, M. B.
J., Fa, J. E., et al. (2015). Synthesising bushmeat research effort in West
and Central Africa: a new regional database. Biol. Conserv. 181, 199–205.
doi: 10.1016/j.biocon.2014.11.001
Trolliet, F., Bauman, D., Forget, P.-M., Doucet, J.-L., Gillet, J.-F., and Hambuckers,
A. (2019). How complementary are large frugivores for tree seedling
recruitment? A case study in the Congo Basin. J. Trop. Ecol. 35, 223–236.
doi: 10.1017/S026646741900018X
Wilkie, D. S., Bennett, E. L., Peres, C. A., and Cunningham, A. A.
(2011). The empty forest revisited. Ann. N. Y. Acad. Sci. 1223, 120–128.
doi: 10.1111/j.1749-6632.2010.05908.x
Wilkie, D. S., Bennett, E. L., Starkey, M., Abernethy, K., Fotso, R. C.,
Maisels, F., et al. (2006). If trade in bushmeat is legalized can the
laws be enforced and wildlife survive in Central Africa: evidence from
Gabon. J. Int. Wildlife Law Policy 9, 335–349. doi: 10.1080/138802906010
39287
Wilkie, D. S., Starkey, M., Abernethy, K., Effa Nsame, E., Telfer, P., and Godoy,
R. (2005). Role of prices and wealth in consumer demand for bushmeat in
Gabon, Central Africa. Conserv. Biol. 19, 1–7. doi: 10.1111/j.1523-1739.2005.0
0372.x
Wilkie, D. S., Wieland, M., Boulet, H., Le Bel, S., Vliet, N., Cornelis, D., et al.
(2016). Eating and conserving bushmeat in Africa. Afr. J. Ecol. 54, 402–414.
doi: 10.1111/aje.12392
Conflict of Interest: The authors declare that the research was conducted in the
absence of any commercial or financial relationships that could be construed as a
potential conflict of interest.
Copyright © 2019 Wilkie, Wieland and Poulsen. This is an open-access article
distributed under the terms of the Creative Commons Attribution License (CC BY).
The use, distribution or reproduction in other forums is permitted, provided the
original author(s) and the copyright owner(s) are credited and that the original
publication in this journal is cited, in accordance with accepted academic practice.
No use, distribution or reproduction is permitted which does not comply with these
terms.
Frontiers in Ecology and Evolution | www.frontiersin.org 8September 2019 | Volume 7 | Article 357
... Diverse forest allocations may have contrasted potentials for the conservation of biodiversity (Panlasigui et al., 2018;Poulsen et al., 2011) and the supply of ES (Nasi et al., 2011;Plieninger et al., 2015;Wilkie et al., 2019), considering different user rights for rural people's access to forest resources. Other determinants may also influence biodiversity and ES: proximity to villages (Beirne et al., 2019) and roads (Kleinschroth et al., 2019) could impact biodiversity, whereas land use changes and local socio-demography (Carpenter et al., 2006;Zhang et al., 2016) may influence ES. ...
... Indeed, perceptions of the supply of these ES were highly homogeneous among respondents and were then less controversial among different forest areas (Lhoest et al., 2019). The identification of ES determinants is also crucial in order to design sustainable planning strategies, disentangling the roles of forest management (Nasi et al., 2011;Plieninger et al., 2015;Wilkie et al., 2019), local environment (Hartter et al., 2014;Quintas-Soriano et al., 2016), and socio-demography (Carpenter et al., 2006;Zhang et al., 2016). ...
... In a sustainable bushmeat exploitation scenario, bushmeat could only contribute to 10-18% of the whole protein supply across Cameroon and other sources of protein would be needed from the agricultural sector (Fa et al., 2003). Many forest areas in Central Africa are already considered as almost empty of wildlife (Wilkie et al., 2019), and 55% of species are being hunted unsustainably in Central Africa according to the IUCN Red List (Taylor et al., 2015). ...
Thesis
Full-text available
Due to human-driven environmental changes, planet Earth has entered the new Anthropocene era, with major impact on biological diversity recognized as the sixth mass extinction period. The concepts of biodiversity and ecosystem services (ES) have risen to objectify and measure the human impacts on ecosystems and the many-fold contributions of ecosystems to human well-being. Among global terrestrial ecosystems, tropical forests are particularly important for the conservation of biodiversity and for the provision of ES. Agricultural conversion, logging, hunting, commercial poaching and over-harvesting lead to deforestation, degradation and defaunation of tropical forests, with highly variable consequences depending on many local factors. In Central Africa in particular, biodiversity and ES have been far less studied than in other tropical regions, despite the vital roles of these tropical forests in the livelihood of tens of millions of people in a context of high poverty. A better understanding of the determinants of biodiversity and ES in Central Africa is crucial for improving human well-being and the resilience of forest ecosystems. Despite the still relatively preserved tree cover across the region, biodiversity and ES may differ depending on forest land management and allocations. Therefore, the objective of this thesis is to assess the conservation value of tropical forests in southeastern Cameroon, as well as the supply of ES and use by local populations, in three contrasted forest allocations: a protected area, a Forest Stewardship Council (FSC)-certified logging concession, and three community forests. First, we assessed the conservation value of the three forest allocations, examining species richness and composition of two taxonomic groups: mammals inventoried with 44 camera traps, and dung beetles inventoried with 72 pitfall traps (Chapter 2). We also aimed to identify the determinants of forest conservation value, disentangling the effects of forest allocations, proximity to human settlements (villages and roads), and local forest habitat. Mammal and dung beetle species showed lower species richness in the community forests than in the protected area, and intermediate values in the logging concession. Proximity to human settlements and disturbance was negatively correlated to species richness of both groups, negatively correlated with species body size, and associated to the loss of the most threatened mammal species. The high species variability among forest allocations (i.e., spatial turnover) suggests that any conservation initiative should integrate many sites to protect a multitude of species, and not only large isolated areas. The high conservation value of the protected area has been confirmed, and the logging concession can play a complementary role in conservation strategies through landscape connectivity. In contrast, community forests are particularly defaunated due to their proximity to roads and villages, but they still provide wild proteins to local populations. Second, we assessed the perceptions of the supply of ES by tropical forests to local populations, and the determinants of these perceptions (Chapter 3). We evaluated the significance and abundance of ES by conducting a questionnaire survey with 225 forest stakeholders. The most significant ES perceptions were provisioning services (93% of respondents) and cultural services (68%), while regulating services were much less reported (16%). The perceptions of ES abundance were relatively homogeneous among forest allocations and respondents. Bushmeat provision has been identified as the only significant ES for local populations that is not supplied in high abundance. Third, we depicted the use of ES by local populations in three villages, and we evaluated its determinants and sustainability (Chapter 4). We used diverse interviews and field surveys to assess three provisioning services (bushmeat, firewood, and timber) and five cultural services (cultural heritage, inspiration, spiritual experience, recreation, and education). On average, local populations consumed 56 kg of bushmeat person–1 year–1 (hunting zones covering on average 213 km² per village), 1.17 m³ of firewood person–1 year–1 (collection zones on average 4 km² per village), and 0.03 m³ of timber person–1 year–1. On average, 59% of respondents recognized the importance of cultural services. The main determinants of ES use were forest allocations, population size, and deforestation rate, and we also showed slight differences between Baka and Bantu people in the use of cultural services. Firewood and timber have been shown to be used sustainably by local populations in this area, whereas bushmeat hunting and consumption have exceeded sustainability thresholds. Finally, the main findings of the thesis are summarized and their practical implications are discussed, in particular for the role of forest allocations (Chapter 5). The potential reconciliation between conservation and the sustainable use of tropical forests is discussed. Methodological feedbacks are given for the use of mammals and dung beetles as biodiversity indicators. Research perspectives are presented for a better understanding of the interactions between biodiversity and ES. Finally, different perspectives for integrating the concept of ES in tropical forest management are given: for instance, identifying and resolving conflicts among stakeholders, raising awareness, making decisions, or evaluating the effectiveness of conservation measures. In particular, ES are increasingly used in concrete management applications, such as FSC-certification, payments for environmental services, UNESCO Man and Biosphere Reserves, and various development projects.
... Indeed, perceptions of the supply of these ES were highly homogenous among respondents and were then less controversial among different forest areas [7]. The identification of ES determinants is also crucial in order to design sustainable planning strategies, disentangling the roles of forest management [16,27,45], local environment [46,47], and socio-demography [48,49]. ...
... In a sustainable bushmeat exploitation scenario, bushmeat could only contribute to 10%-18% of the whole protein supply across Cameroon and other sources of protein would be needed from the agricultural sector [91]. Many forest areas in Central Africa are already considered as almost empty of wildlife [45], and 55% of species are being hunted unsustainably in Central Africa according to the IUCN Red List [93]. ...
Article
Full-text available
In order to improve sustainability and design adequate management strategies in threatened tropical forests, integrated assessments of the use of ecosystem services are needed, combining biophysical, social, and economic approaches. In particular, no integrated ecosystem services (ES) assessment has been conducted in Central Africa, where rural communities deeply depend on forests in a high-poverty context. Here, we aimed to quantify the use of ES provided by tropical forests to local populations in the Dja area (Cameroon), identify its determinants and evaluate its sustainability. We conducted various interviews and field surveys with 133 households in three villages, focusing on three provisioning services (bushmeat, firewood, and timber), and five cultural services (cultural heritage, inspiration, spiritual experience, recreation, and education). Local populations consumed a mean of 56 kg of bushmeat/person/year (hunting zones covering on average 213 km2), 1.17 m3 of firewood/person/year (collection zones covering on average 4 km2), and 0.03 m3 of timber/person/year. Between 25% and 86% of respondents considered cultural services as important. The use of ES was mainly influenced by population size, deforestation rate, and forest allocations, whereas the influence of socio-demographic characteristics of households remained limited to slight differences between Baka and Bantu people. We conclude that the consumption of firewood and timber is sustainable, whereas high hunting pressure has resulted in severe defaunation in the area due to the large decline in the abundance and biomass of forest mammals hunted for bushmeat by local populations.
... Trophy hunting in Africa dates to the era of the arrival of European explorers, traders and hunters and the colonial administration of the African continent around the 1800s (Mbaiwa, 2002;Ochieng, 2019;Ochieng et al., 2020). Trophy hunting Muposhi et al., 2016;Sorensen, 2015) also known as a form of consumptive tourism (Mwakiwa et al., 2016;Novelli et al., 2006;Tremblay, 2001), sustainable hunting (Damm, 2008;Fa et al., 2014;Forstner et al., 2006;Wilkie et al., 2019), conservation hunting or hunting (Rogan et al., 2017) is a term used interchangeably with "safari' or 'sport' hunting (McNamara et al., 2020). It refers to tourists who pay to engage in hunting, usually in the company of a professional guide, to obtain a "trophy" (i.e. ...
Article
Botswana re-introduced trophy hunting in 2019. This generated a debate about the relevance of trophy hunting in achieving wildlife conservation and human well-being among wildlife stakeholders. These stakeholders include the Government of Botswana, local agro-pastoralists, photographic and trophy hunting tourism operators and anti-hunting groups that differ in opinion on the acceptability of trophy hunting as socio-economic development and conservation tool. This paper, therefore, adopts the socio-ecological framework and uses Spivak’s rhetoric question: “Can the Subaltern Speak”, to analyse contradictions of trophy hunting, human well-being and wildlife conservation trajectory in Botswana. The study is qualitative and makes use of interviews and secondary data sources. The results indicate that the Government of Botswana and communities (agro-pastoralists) especially those residing in wildlife areas prefer both trophy hunting and photo-tourism as a strategy to derive tourism benefits and achieve wildlife conservation. Conversely, animal rights groups reject trophy hunting noting its failure to promote conservation. The paper concludes the socio-ecological framework is the ideal guide for wildlife conservation and human well-being in wildlife areas. Both photographic tourism and trophy hunting are sustainable land use options with the potential to achieve wildlife conservation and human well-being in Botswana.
... If currently high capture rates cannot be sustained, hunters would have to reduce their offtake. Persuading hunters to incur such short-term opportunity costs, even just temporarily, would be difficult unless they can be compensated for any lost food or income 58 . In this case, part of the carbon credit revenue could be reserved for PES programs (e.g. ...
Article
Full-text available
Whether sustainable or not, wild meat consumption is a reality for millions of tropical forest dwellers. Yet estimates of spared greenhouse gas (GHG) emissions from consuming wild meat, rather than protein from the livestock sector, have not been quantified. We show that a mean per capita wild meat consumption of 41.7 kg yr −1 for a population of ~150,000 residents at 49 Amazonian and Afrotropical forest sites can spare ~71 MtCO 2-eq annually under a bovine beef substitution scenario, but only ~3 MtCO 2-eq yr −1 if this demand is replaced by poultry. Wild meat offtake by these communities could generate US$3M or US$185K in carbon credit revenues under an optimistic scenario (full compliance with the Paris Agreement by 2030; based on a carbon price of US$50/tCO 2-eq) and US$1M or US$77K under a conservative scenario (conservative carbon price of US$20.81/tCO 2-eq), representing considerable incentives for forest conservation and potential revenues for local communities. However, the wild animal protein consumption of ~43% of all consumers in our sample was below the annual minimum per capita rate required to prevent human malnutrition. We argue that managing wild meat consumption can serve the interests of climate change mitigation efforts in REDD+ accords through avoided GHG emissions from the livestock sector, but this requires wildlife management that can be defined as verifiably sustainable.
... Recent peer-reviewed studies show that the sustainability of commercial trade (in live wild animals or their derivatives) is dependent on baseline data and empirical assessments, both of which are currently lacking for the vast majority of commodified species (e.g., Auliya et al., 2016;Marshall et al., 2020;Rowley et al., 2016). Without significant investment in future monitoring and testing of the efficacy of different harvest and trade models (Wilkie et al., 2019), large swathes of wildlife trade presently rely on the business-as-usual assumption of sustainable use until proven otherwise (Macdonald et al., 2021). ...
Article
The global trade in wildlife affects most major taxonomic groups (Fukushima et al., 2020; Scheffers et al., 2019). Managing wildlife trade requires an accurate understanding of the dimensions of trade and its impacts (positive, neutral, or negative) on the conservation of native wildlife populations. We are concerned that assertions made by Natusch et al. (2021) in “The Perils of Flawed Science in Wildlife Trade Literature” undermine efforts to obtain a representative and accurate understanding of the dimensions, sustainability, and conservation implications of wildlife trade. Natusch et al. propose that suggestions of negative impacts of trade on species reflect that “philosophical biases are common in the scientific literature on trade in wildlife.” They draw this conclusion from a series of poorly evidenced and misleading assertions based on a report on the luxury and fashion trade in wildlife (Sosnowski & Petrossian, 2020). They present Sosnowski and Petrossian (2020) as “a key example … to illustrate the threat of philosophical bias in research on the wildlife trade” in reference to what they claim to be biases on the part of researchers seeking to better understand accurate measures of traded wildlife. We focused on misleading assertions in Natusch et al. that relate to several other studies that quantify impacts and dimensions of wildlife trade.
... In the absence of hunting regulations and enforcement, this may result in a short-term boom in income for participants in the trade. However, the consequent rapid depletion of hunted species then threatens the food security of community members reliant on wild meat for food (108,111) and may also result in an income bust for hunters and traders (112). ...
Article
Several hundred species are hunted for wild meat in the tropics, supporting the diets, customs, and livelihoods of millions of people. However, unsustainable hunting is one of the most urgent threats to wildlife and ecosystems worldwide and has serious ramifications for people whose subsistence and income are tied to wild meat. Over the past 18 years, although research efforts have increased, scientific knowledge has largely not translated into action. One major barrier to progress has been insufficient monitoring and evaluation, meaning that the effectiveness of interventions cannot be ascertained. Emerging issues include the difficulty of designing regulatory frameworks that disentangle the different purposes of hunting, the large scale of urban consumption, and the implications of wild meat consumption for human health. To address these intractable challenges, we 19.2 Ingram et al.
... In the absence of hunting regulations and enforcement, this may result in a short-term boom in income for participants in the trade. However, the consequent rapid depletion of hunted species then threatens the food security of community members reliant on wild meat for food (108,111) and may also result in an income bust for hunters and traders (112). ...
Article
Several hundred species are hunted for wild meat in the tropics, supporting the diets, customs, and livelihoods of millions of people. However, unsustainable hunting is one of the most urgent threats to wildlife and ecosystems worldwide and has serious ramifications for people whose subsistence and income are tied to wild meat. Over the past 18 years, although research efforts have increased, scientific knowledge has largely not translated into action. One major barrier to progress has been insufficient monitoring and evaluation, meaning that the effectiveness of interventions cannot be ascertained. Emerging issues include the difficulty of designing regulatory frameworks that disentangle the different purposes of hunting, the large scale of urban consumption, and the implications of wild meat consumption for human health. To address these intractable challenges, we propose eight new recommendations for research and action for sustainable wild meat use, which would support the achievement of the United Nations Sustainable Development Goals. Expected final online publication date for the Annual Review of Environment and Resources, Volume 46 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
... This urbanization and sprawl coupled with human population growth and migration portends the illegal urban wild meat trade is a threat for conservation and sustainable development (Luiselli et al., 2019). With the continued growth and wealth of urban populations globally, urban demand for wild meat easily crests beyond sustainable levels (East, Kümpel, Milner-Gulland, & Rowcliffe, 2005;Robinson & Bennett 2005;Wilkie, Wieland, & Poulsen, 2019;Bizri et al., 2020). As such, urban areas are becoming a key geographic space for illegal wild meat trade. ...
Article
Full-text available
At unsustainable rates and in illegal contexts, the wild meat trade is a driver of species extinction; it can also threaten ecosystem services, local food security and contribute to the risk of zoonotic disease spread. The restaurant and catering sectors are understudied groups in conservation, both with regards to the legal and illegal wild meat trade and particularly in urban areas. Restaurateurs are key actors between wild meat consumers and suppliers and thus play a central role in the supply chain. This study applied a crime science hot product approach to characterize: (a) restaurateur perceptions of urban wild meat consumption; (b) wildlife species most at risk in the urban wild meat trade; and (c) the differences between restaurants in Kinshasa (Democratic Republic of the Congo) and Brazzaville (Republic of the Congo). Through focus groups in both cities, participants affirmed that in urban centers wild meat is considered a luxury item and sign of wealth. Monkeys were seen as a hot product in both cities, but we found a greater variety of hot wild meat products in Brazzaville. When looking at the differences between the restaurant tier levels, middle‐tiered restaurants identified pangolin and antelopes as being hot products, rather than monkeys as with upper and lower‐tiered restaurants. By applying a hot product analysis, we identified the wild meat groups most likely to be targeted by the urban wild meat trade. Findings herein offer novel opportunities to better tailor and prioritize conservation interventions against illegal trade using design against crime or other crime prevention strategies.
... Although bushmeat is one of the major sources of protein for rural communities, the unsustainable hunting and trade of bushmeat have become a widespread commercial activity, representing a significant extinction threat to wild animal populations (Ripple et al., 2016;Wilkie et al., 2019). While many tribes in rural communities have hunted wild animals for subsistence over millennia, the unsustainable nature of this practice has accelerated with severe negative consequences on wild animal populations (Smith et al., 2016). ...
Article
Full-text available
This study investigated the attitudes of the people living in three adjacent communities close to the Bomfobiri wildlife sanctuary in Ghana concerning the observation of the cultural, seasonal closures of hunting. The cognitive and motivational approaches to attitude theory in wildlife management guided, under the phenomenology method, the collection of qualitative data on the importance of the seasonal closure of hunting and its implementation challenges. This inquiry was deemed crucial to improving the disjointed relationship between park management and local communities that often make wildlife conservation and tourism difficult at the Bomfobiri Wildlife Sanctuary. Forty-five key wildlife stakeholders, including park officers, traditional authorities, elderly residents, and bushmeat traders, were purposively selected with some interviewed personally and others engaged in focus group discussions. Despite a more significant number of stakeholders admitting the importance of the seasonal closure of hunting, some challenges impeded its implementation. These included the absence of alternative arrangements to support hunters during the period for the annual closure of hunting; lack of proper sensitisation and education on the hunting ban; absence of transparency in the equitable sharing of proceeds from wildlife tourism at the Bomfobiri Wildlife Sanctuary among park officers (Government) and the traditional authorities; the booming bushmeat business and the fear of losing customers after the fallow period; and purported corruption on the part of park officers, threatening the observation of the seasonal closure of hunting. The study has offered proactive suggestions to the Wildlife Division of the Forestry Commission and mainly to park management at the Bomfobiri Wildlife Sanctuary on how to address these challenges and improve wildlife management and sustainable wildlife tourism potentials in Ghana. Paramount among them is the tactful provision of alternative sources of livelihood and the establishment of enterprises in non-timber forest products as sources of income for hunters during the seasonal hunting ban.
Article
Full-text available
Sustainability promotes a feasible strategy to achieve a continuous development of the economy, society, and environment. This study aims to analyze the growing efforts on researches made by academic communities in exploring the sharing economy as a potential approach to promote sustainable development. A bibliometric approach with VOSviewer and COOC analysis was applied. A total number of 975 published articles were analyzed in this study. As a result, it was found that few studies have shed light on collaborative and sustainable consumption, climate change, and bioeconomy in the sharing economy by country, such as renewable resources and business models, circular economy in China, and life cycle assessment, particularly taking evidence from the urban mobility services in China. It was also revealed that there is a new indiscipline research trend in the field of sustainable development such as sustainable business models, game theory, blue economy, peer-to-peer accommodation, smart grids, and electric vehicles. Other trend concentrates on technological advancements and policies to promote sustainable development in the sharing economy.
Article
Full-text available
Roads facilitate development in remote forest regions, often with detrimental consequences for ecosystems. In the Congo Basin, unpaved logging roads used by timber firms, as well as paved and unpaved public roads, have expanded greatly. Comparing old (before 2003) and new (2003–2018) road datasets derived from Landsat imagery, we show that the total length of road networks inside logging concessions in Central Africa has doubled since 2003, whereas the total length of roads outside concessions has increased by 40%. We estimate that 44% of roads in logging concessions were abandoned by 2018, as compared to just 12% of roads outside concessions. Annual deforestation rates between 2000 and 2017 near (within 1 km) roads increased markedly and were highest for old roads, lowest for abandoned roads and generally higher outside logging concessions. The impact of logging on deforestation is partially ameliorated by the nearly fourfold higher rate of road abandonment inside concessions, but the overall expansion of logging roads in the Congo Basin is of broad concern for forest ecosystems, carbon storage and wildlife vulnerable to hunting. Road decommissioning after logging could play a crucial role in reducing the negative impacts of timber extraction on forest ecosystems.
Article
Full-text available
Industrial-scale oil palm cultivation is rapidly expanding in Gabon, where it has the potential to drive economic growth, but also threatens forest, biodiversity and carbon resources. The Gabonese government is promoting an ambitious agricultural expansion strategy, while simultaneously committing to minimize negative environmental impacts of oil palm agriculture. This study estimates the extent and location of suitable land for oil palm cultivation in Gabon, based on an analysis of recent trends in plantation permitting. We use the resulting suitability map to evaluate two proposed approaches to minimizing negative environmental impacts: a High Carbon Stock (HCS) approach, which emphasizes forest protection and climate change mitigation, and a High Conservation Value (HCV) approach, which focuses on safeguarding biodiversity and ecosystems. We quantify the forest area, carbon stock, and biodiversity resources protected under each approach, using newly developed maps of priority species distributions and forest biomass for Gabon. We find 2.7–3.9 Mha of suitable or moderately suitable land that avoid HCS areas, 4.4 million hectares (Mha) that avoid HCV areas, and 1.2–1.7 Mha that avoid both. This suggests that Gabon’s oil palm production target could likely be met without compromising important ecosystem services, if appropriate safeguards are put in place. Our analysis improves understanding of suitability for oil palm in Gabon, determines how conservation strategies align with national targets for oil palm production, and informs national land use planning.
Article
Full-text available
In Africa, overhunting of tropical wildlife for food remains an intractable issue. Donors and governments remain committed to invest in efforts to both conserve and allow the sustainable use of wildlife. Four principal barriers need to be overcome: 1) communities are not motivated to conserve wildlife long-term because they have no formal rights to benefit from wildlife, or to exclude others from taking it on their land; 2) multi-species harvests, typical of bushmeat hunting scenarios, place large-bodied species at risk of extinction; 3) wildlife production cannot expand, in the same way that livestock farming can, to meet the expected growth in consumer demand; and 4) wildlife habitat is lost through conversion to agriculture, housing, transportation networks, and extractive industries. In this review, we examine the actors involved in the use of wildlife as food and discuss the possible solutions required to address urban and rural bushmeat consumption. Interventions must tackle use and conservation of wildlife through the application of context-relevant interventions in a variety of geographies across Africa. That said, for any bushmeat solution to work there needs to be concurrent and comparable investment in strengthening the effectiveness of protected area management and enforcement of wildlife conservation laws.
Article
Full-text available
Terrestrial mammals are experiencing a massive collapse in their population sizes and geographical ranges around the world, but many of the drivers, patterns and consequences of this decline remain poorly understood. Here we provide an analysis showing that bushmeat hunting for mostly food and medicinal products is driving a global crisis whereby 301 terrestrial mammal species are threatened with extinction. Nearly all of these threatened species occur in developing countries where major coexisting threats include deforestation, agricultural expansion, human encroachment and competition with livestock. The unrelenting decline of mammals suggests many vital ecological and socio-economic services that these species provide will be lost, potentially changing ecosystems irrevocably. We discuss options and current obstacles to achieving effective conservation, alongside consequences of failure to stem such anthropogenic mammalian extirpation. We propose a multipronged conservation strategy to help save threatened mammals from immediate extinction and avoid a collapse of food security for hundreds of millions of people.
Article
Full-text available
Anthropocene defaunation is the global phenomenon of human-induced animal biodiversity loss. Understanding the patterns and process of defaunation is critical to predict outcomes for wildlife populations and cascading consequences for ecosystem function and human welfare. 2.We investigated a defaunation gradient in northeastern Gabon by establishing 24 transects at varying distances (2–30 km) to rural villages and surveying the abundance and composition of vertebrate communities. Distance from village was positively correlated with observations of hunting (shotgun shells, campfires, hunters), making it a good proxy for hunting pressure. 3.Species diversity declined significantly with proximity to village, with mammal richness increasing by roughly 1.5 species every 10 km travelled away from a village. Compared to forest far from villages, the wildlife community near villages consisted of higher abundances of large birds and rodents and lower abundances of large mammals like monkeys and ungulates. 4.Distance to nearest village emerged as a key driver of the relative abundance of five of the six taxonomic guilds, indicating that the top–down force of hunting strongly influences large vertebrate community composition and structure. Several measures of vegetation structure also explained animal abundance, but these varied across taxonomic guilds. Forest elephants were the exception: no measured variable or combination of variables explained variation in elephant abundances. 5.Synthesis and applications. Hunting is concentrated within 10 km around villages, creating a hunting halo characterized by heavily altered animal communities composed of relatively small-bodied species. Although the strongest anthropogenic effects are relatively distance-limited, the linear increase in species richness shown here even at distances 30 km from villages suggests that hunting may have altered vertebrate abundances across the entire landscape. Central African forests store >25% of the carbon in tropical forests and are home to 3000 endemic species, but roughly 53% of the region lies within the village hunting halo. Resource management strategies should take into account this hunting-induced spatial variation in animal communities. Near villages, resource managment should focus on sustainable community-led hunting programs that provide long-term supplies of wild meat to rural people. Resource management far from villages should focus on law enforcement and promoting industry practices that maintain remote tracts of land to preserve ecosystem services like carbon storage and biodiversity. This article is protected by copyright. All rights reserved.
Article
Full-text available
Long-term food demand scenarios are an important tool for studying global food security and for analysing the environmental impacts of agriculture. We provide a simple and transparent method to create scenarios for future plant-based and animal-based calorie demand, using time-dependent regression models between calorie demand and income. The scenarios can be customized to a specific storyline by using different input data for gross domestic product (GDP) and population projections and by assuming different functional forms of the regressions. Our results confirm that total calorie demand increases with income, but we also found a non-income related positive time-trend. The share of animal-based calories is estimated to rise strongly with income for low-income groups. For high income groups, two ambiguous relations between income and the share of animal-based products are consistent with historical data: First, a positive relation with a strong negative time-trend and second a negative relation with a slight negative time-trend. The fits of our regressions are highly significant and our results compare well to other food demand estimates. The method is exemplarily used to construct four food demand scenarios until the year 2100 based on the storylines of the IPCC Special Report on Emissions Scenarios (SRES). We find in all scenarios a strong increase of global food demand until 2050 with an increasing share of animal-based products, especially in developing countries.
Article
Large frugivores provide critical seed dispersal services for many plant species and their extirpation from forested ecosystems can cause compositional shifts in regenerating plant cohorts. Yet, we still poorly understand whether large seed-dispersers have complementary or redundant roles for forest regeneration. Here, to assess the functional complementarity of large-bodied frugivores in forest regeneration, we quantified the effects of varying abundance of hornbills, primates and the forest elephant on the density, species richness and the mean weighted seed length of animal-dispersed tree species among seedlings in five sites in a forest–savanna mosaic in D. R. Congo, while accounting for percentage forest cover and the local presence of fruiting trees. We found that the abundance of primates was positively associated with species richness of seedlings, while percentage forest cover was negatively associated ( R² = 0.19). The abundance of hornbills, the presence of elephants and percentage forest cover were positively associated with mean seed length of the regenerating cohort ( R² = 0.13). Spatially explicit analysis indicated that some additional processes have an important influence on these response indices. Primates would seem to have a preponderant role for maintaining relatively high species richness, while hornbills and elephant would seem to be predominantly responsible for the recruitment of large-seeded trees. Our results could indicate that these taxa of frugivores play complementary functional roles for forest regeneration. This suggests that the extirpation of one or more of these dispersers would likely not be functionally compensated for by the remaining taxa, hence possibly cascading into compositional shifts.
Article
Tropical areas are facing a bushmeat crisis involving the systematic over-exploitation of large-bodied mammals for both subsistence and commercial purposes. We hypothesize that because hunting generally originates from villages, it will create "halos of defaunation" where abundances of large mammals increase with distance away from villages. Whilst such patterns have been well characterized at the landscape scale, examining how de-faunation halos vary between different villages has received considerably less attention. Forests immediately surrounding villages are of considerable importance to the people residing within them and the factors hypothesized to influence local defaunation halos (e.g. village size, hunting practices and access to local markets) may affect local livelihoods and the ecological integrity of nearby forests. To address this, we adopted a par-ticipatory approach to establish and monitor sixty transects across ten village-distance gradients (1-8 km) in Gabon. Trained paraecologists, recruited from local villages, walked each transect twice monthly to determine the encounter rates of medium and large mammals across the village distance gradient and monitored village-level bushmeat availability. We found that overall rates of mammal observation and estimated species richness were constant across the village-distance gradient, however the total number of individuals encountered and bushmeat biomass were lower close to villages-consistent with local depletion of wildlife. These general trends were underpinned by depleted mammal species diversity with increasing proximity to villages and a marked shift in mammal community composition: small, non-hunted species were encountered most frequently near villages, whereas large, hunted species were encountered most frequently away from villages. We found some evidence for inter-village variation in the strength and depth of defaunation halos, which may be driven in part by the village-level hunting intensity. Several of the key parameters identified in landscape-scale bushmeat studies did not detectably influence village-level defaunation (e.g. road or market distance). Despite the prevalence of bushmeat hunting in the region, the conservation value of forests immediately surrounding villages was demonstrated through the detection of large-bodied species of conservation concern (e.g. chimpanzee and gorilla) at a high proportion of survey locations. The compositional shifts in mammal communities detailed here will ultimately lead to the altered composition and diversity of forests around villages, with potential implications for human livelihoods, health and transmission of zoonotic disease. This research also demonstrates the effectiveness of engaging paraecologists to answer focused ecological questions-the first step in facilitating effective natural resource management by local communities.