No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Population and Trophy Quality Trends of Three Gregarious Herbivores in an Insulated Semi-Arid Savanna Ecosystem (Cawston Ranch, Zimbabwe), 1997–2014
Abstract
Long term monitoring of population estimates and trophy size trends is requisite to ensure that trophy hunting is sustainable. We explored the influence of trophy hunting on population size and trophy quality of impala (Aepyceros melampus), greater kudu (Tragelaphus strepsiceros) and sable (Hippotragus niger) antelopes from 1997 to 2014 in Cawston Ranch, Zimbabwe. Population estimates of the three species showed a cyclical declining trend, albeit being statistically insignificant for the three species. Hunting pressure had no significant effect on the population estimates of the three species for the period 1997-2014. Impala population declined (-30 %) between 2003 and 2008 possibly due to increased illegal hunting pressure associated with land invasions during this period. Trophy size of all species declined over time, 2004-2014, (impala (-1.3 %), kudu (-3.9 %), sable (-2.6 %) possibly due diet quality and loss of genetic variability in these populations. However, trophy size for greater kudu and sable were within the minimum score range of the Safari Club International. We recommend research on genetic variability and inbreeding levels of hunted populations in closed ecosystems to inform adaptive management as a way of ensuring sustainability of trophy hunting as a conservation tool in small isolated parks in Africa.
... In the case of the density differences observed in KNP and GR, these differences may, however, largely be due to variation in habitat structure (greater proportion of grasslands in KNP compared to the more wooded RGR) and unlikely due to the fact that the monitored species (except for giraffe which cannot be hunted legally in Tanzania) are legally hunted . Although our data do not allow more detailed analysis of the sustainability of trophy hunting (Crosmary et al., 2013;Milner et al., 2007;Muposhi et al., 2015), our data suggest that long-term persistence of large herbivore population in trophy hunting areas is possible. Due to the lack of detailed information on hunting off-take, we recommend to continue wildlife monitoring and undertake more targeted and comprehensive research to assess the sustainability of trophy hunting. ...
In many parts of East Africa, wildlife populations have declined over the past decades. Given these trends, site-based studies are needed to assess how protected areas with differing management strategies enable the effective conservation of wildlife populations. In Tanzania, game reserves are managed for tourist hunting, while national parks are managed for non-consumptive wildlife-based tourism. To assess the relative performance of these management strategies, we here focus on two areas: Rukwa Game Reserve (RGR) and Katavi National Park (KNP). Based on systematically designed line distance surveys in 2004 and 2021, we compared densities and group sizes of large mammal populations (African elephant, giraffe, buffalo, zebra, topi, and hartebeest) over time. Contrary to published ecosystem-wide declines observed in numerous species which considered earlier baselines, we did not detect significant population declines between 2004 and 2021. While these new results showing apparent stable populations do not invalidate earlier studies on wildlife declines, they could indicate a stabilisation phase after declines. This highlights the importance of considering appropriate temporal baselines and historical contexts when assessing conservation effectiveness.
The selective nature of trophy hunting may cause changes in desirable phenotypic traits in harvested species. A decline in trophy size of preferred species may reduce hunting destination competitiveness thus compromising the sustainability of trophy hunting as a conservation tool. We explored the trophy quality and trends in harvesting patterns (i.e., 2004–2015) of Cape buffalo (Syncerus caffer), African elephant (Loxodonta africana), greater kudu (Tragelaphus strepsiceros) and sable (Hippotragus niger) in Matetsi Safari Area, northwest Zimbabwe. We used long-term data on horn and tusk size, age, quota size allocation and offtake levels of selected species. To analyse the effect of year, area and age on the trophy size, quota size and offtake levels, we used linear mixed models. One sample t-test was used to compare observed trophy size with Safari Club International (SCI) minimum score. Trophy sizes for Cape buffalo and African elephant were below the SCI minimum score. Greater kudu trophy sizes were within the minimum score threshold whereas sable trophy sizes were above the SCI minimum score between 2004 and 2015. Age at harvest for Cape buffalo, kudu and sable increased whilst that of elephant remained constant between 2004 and 2015. Quota size allocated for buffalo and the corresponding offtake levels declined over time. Offtake levels of African elephant and Greater kudu declined whilst the quota size did not change between 2004 and 2015. The quota size for sable increased whilst the offtake levels fluctuated without changing for the period 2004–2015. The trophy size and harvesting patterns in these species pose a conservation and management dilemma on the sustainability of trophy hunting in this area. We recommend: (1) temporal and spatial rotational resting of hunting areas to create refuge to improve trophy quality and maintenance of genetic diversity, and (2) introduction of variable trophy fee pricing system based on trophy size.
ABSTRACT
We explored the relationships between protected area (PA) staff and adjacent communities
in and around four PAs in Zimbabwe. A total of 938 local people and 133 PA staff
participated in the survey conducted between July 2013 and February 2014. Our results
showed that communities generally perceived a negative relationship with PA staff, while
PA staff generally perceived a positive relationship with local communities. Only benefitsharing
had a different effect on PA staff–community relationship for the PA staff and
community samples. In contrast, communication, perceptions (both communities’ and PA
staff’s), community involvement in conservation, history of PA creation, and problems
caused by PA existence to the communities or by communities to PAs had the same effect
on PA staff–community relationship from both perspectives. We recommend that both
conservation agencies and communities should pay more attention to factors that influence
PA staff–community relationships so as to nurture positive relationships between PA staff
and local communities.
The present paper explores trends and variations in trophy size among wildlife species hunted in the Ugalla Game Reserve (UGR) of western Tanzania, in relation to hunting success (animals shot species-1 quota-1). Data on trophy hunting from 2006 – 2010 were obtained from the UGR office in Tabora Region. Forty-seven species were targeted by trophy hunters. Hunting success differed significantly across the species (Generalised Linear Model [GLM] with a binomial error structure: deviance chi-square [2] = 9.64, d.f. = 44, p<0.001). Twenty-eight species had trophy size measurements, but only 6 species had measurements taken consistently throughout the data period. Although most of the shot animals were above their minimum trophy size limits (official trophy limits below which animals could not be removed) there was significant variation among species (GLM with normal errors: F5,201 = 509.12, p<0.001). Time (years) had no significant effect on trophy size, but the trend over time in trophy size differed significantly among species (F5,194 = 5.42, p<0.001). Of the trophy species, greater kudu (Tragelaphus strepsiceros) had the largest mean trophy size, whereas warthog (Phacochoerus africanus) had the lowest trophy size and showed a considerable decline. The majority of the animals had trophy sizes hovering just above their minimum limits. This should be monitored rigorously to avoid removing large numbers of actively breeding animals.
Water is one of the fundamental requirements of life but there has been little study on the use
of water by free-ranging wildlifecommunities.We investigated the timing of waterhole use by
African fauna using webcams to determine whether this mode of data collection was viable,
to determine whether animals drank randomly throughout the day, whether there were differences
between guilds in waterhole use and finallywe created a relative rank of water dependency
by comparing waterhole use with the relative abundance of species at Kruger and
Pilanesberg National Parks.We used webcams sited at waterholes in South Africa’s Kruger
and Pilanesberg, Madikwe Game Reserve and Tembe Elephant Park, and Botswana’s
Mashatu Game Reserve to remotely monitor waterhole use at random times throughout the
day. Over the 16-month study period, 1546 observations were made of 30 species at waterholes,
with elephants (Loxodonta africana) and impala (Aepyceros melampus) being the
most frequently observed species. There was a high degree of diurnal overlap in waterhole
use amongst the herbivores, but they partitioned the time of peak waterhole use. Large
predators were largely nocturnal while their prey was invariably diurnal. The index of relative
water use showed that hippopotamus (Hippopotamus amphibius), warthog (Phacochoerus
africanus) and blue wildebeest (Connochaetes taurinus) were highly water-dependent,
whereas lion (Panthera leo), spotted hyaena (Crocuta crocuta) and kudu (Tragelaphus
strepsiceros) appear relatively water independent. African fauna may partition waterhole
use to avoid competition and predation. The use of webcams is a novel technique to allow
remote monitoring of aspects of the ecology of African wildlife at minimal cost.
Key words: camera trap survey, Carnivora, competition potential, drinking patterns, resource
partitioning, elephant, remote observations, ungulates, water requirements, webcam monitoring
Wildlife populations are declining severely in many protected areas and unprotected pastoral areas of Africa. Rapid large-scale land use changes, poaching, climate change, rising population pressures, governance, policy, economic and socio-cultural transformations and competition with livestock all contribute to the declines in abundance. Here we analyze the population dynamics of 15 wildlife and four livestock species monitored using aerial surveys from 1977 to 2011 within Kajiado County of Kenya, with a rapidly expanding human population, settlements, cultivation and other developments. The abundance of the 14 most common wildlife species declined by 67% on average (2%/yr) between 1977 and 2011 in both Eastern (Amboseli Ecosystem) and Western Kajiado. The species that declined the most were buffalo, impala, wildebeest, waterbuck, oryx, hartebeest, Thomson's gazelle and gerenuk in Eastern Kajiado (70% to 88%) and oryx, hartebeest, impala, buffalo, waterbuck, giraffe, eland and gerenuk in Western Kajiado (77% to 99%). Only elephant (115%) and ostrich (216%) numbers increased contemporaneously in Eastern and Western Kajiado, respectively. Cattle and donkey numbers also decreased on average by 78% in Eastern Kajiado and by 37% in Western Kajiado. Sheep and goats decreased the least in Eastern (28%) but increased in Western (96%) Kajiadio. Livestock dominated (70-80%) the total large herbivore biomass throughout the 1977-2011 monitoring period. The distribution of wildlife contracted dramatically during 1977-2011, most especially for wildebeest, giraffe and impala. Only zebra and ostrich distributions expanded in the county. However, livestock distribution expanded to densely cover most of the county. Our findings point to recurrent droughts, intensifying human population pressures, land use changes and other anthropogenic impacts, decades of ineffective or failed government policies, legislations, law enforcement, management institutions and strategies as the salient causes of the declines and range compressions. We recommend several urgent measures to rehabilitate the depleted wildlife populations and habitat richness, restore their ecological resilience to droughts and secure pastoral livelihoods.
Land use has major effects on wildlife conservation. We studied variations of sable antelope Hippotragus niger densities between 1990 and 2001 in comparison with various land uses in and around Hwange National Park, Zimbabwe. Trends of other ungulates, including elephant Loxodonta africana, were examined simultaneously, because sable may be sensitive to forage and apparent competition and to high elephant densities. Sable densities declined in the whole region, very likely because of adverse rainfall conditions. Densities were constantly higher in the hunting areas and forestry lands than in the national park. Interestingly, elephant densities showed the opposite, with higher densities in the national park than in the adjacent areas. Whether these results reflect a negative effect of high elephant numbers on sable must still be tested directly. Likewise, while habitat characteristics and lion predation did not appear responsible for the higher sable densities outside the national park, they could not be discounted as an influence on the differing sable densities in different land‐use areas. It is clear, however, that high protection status is not always sufficient to ensure adequate conservation of flagship species. We therefore call for further investigations of ecological interactions within protected areas.
Illegal harvesting of wildlife resources is an important challenge facing protected areas in Africa. A better understanding of its nature would improve the way in which it is managed. We investigated the degree of poaching into different types of natural resources and its management implications in Ugalla Game Reserve, western Tanzania, using data on spatial distribution of poaching signs. Poaching signs were distributed nonrandomly through the reserve, which suggested that poachers targeted particular resources at certain areas of the reserve. Logging was the predominant illegal activity, followed by bushmeat hunting and illegal fishing. Logging signs were widespread at Ugalla east and Ugalla south. The latter also contained the highest encounter rate of bushmeat signs. Illegal fishing was extensive around the main rivers in the reserve. For improved conservation enforcement in western Tanzania and similar ecosystems, conservation efforts should take into consideration the distribution and composition of different types of poaching.
Populations that are vulnerable to decline are of particular concern to wildlife managers and uncovering the mechanisms responsible for downward trends is a crucial step towards developing future viable populations. The aims of this study were to better understand the mechanisms behind the historic decline of the sable antelope, Hippotragus niger, population at the Malilangwe Wildlife Reserve (MWR), to assess its future viability and to use this analysis to determine key areas of breakdown in population growth and link these to potential limiting factors. VORTEX, a population viability model was used to assess the future viability of the sable antelope population and a sensitivity analysis was applied to identify the key areas of breakdown in growth. The sable population is currently viable, but remains highly vulnerable to changes in adult female survival, a factor which had the greatest influence on overall population fitness. Lion predation, impacting on the adult segment of the population, appeared to be the main factor responsible for the historic decline at the MWR.
We investigated the rainfall patterns and associated fluctuations of wild large herbivore species in the Great Limpopo Transfrontier Conservation Area (GLTFCA), southern Africa. The study objectives were to: (i) establish the synchrony in rainfall and drought occurrence patterns in Gonarezhou National Park, Zimbabwe, and four adjacent areas, and (ii) determine the responses of different large herbivore species’ populations to droughts. We used annual rainfall data collected from the five sites within the GLTFCA and large herbivore population data collected from multispecies aerial surveys in Gonarezhou and Kruger National Park, South Africa. Our results showed that between 1970 and 2009, Gonarezhou recorded three wet years (1977, 1978 and 2000) and six drought years (1973, 1983, 1989, 1992, 1994 and 2005). However, there were some variations in the drought occurrences between Gonarezhou and the four adjacent areas indicating a weak synchrony in rainfall patterns. Furthermore, seven large herbivore species showed dips in their populations associated with the 1992 severe drought, with most of the species’ populations recovering thereafter. Our study suggests that rainfall does have a strong influence on large herbivore population dynamics especially in really dry years in African savanna ecosystems. Our findings underscore the need for further detailed studies on bottom-up processes influencing large herbivore population trends in savanna ecosystems with high rainfall variability.
The question whether animal populations are top-down and/or bottom-up controlled has motivated a thriving body of research over the past five decades. In this review I address two questions: 1) how do top-down and bottom-up controls influence large herbivore populations? 2) How do human activities and control systems influence the top-down and bottom-up processes that affect large herbivore population dynamics? Previous studies suggest that the relative influence of top-down vs. bottom-up control varies among ecosystems at the global level, with abrupt shifts in control possible in arid and semi-arid regions during years with large differences in rainfall. Humans as superpredators exert top-down control on large wild herbivore abundances through hunting. However, through fires and livestock grazing, humans also exert bottom-up controls on large wild herbivore abundances through altering resource availability, which influences secondary productivity. This review suggests a need for further research, especially on the human-induced top-down and bottomup control of animal populations in different terrestrial ecosystems.
Conservation scientists are increasingly focusing on the drivers of human behavior and on the implications of various sources of uncertainty for management decision making. Trophy hunting has been suggested as a conservation tool because it gives economic value to wildlife, but recent examples show that overharvesting is a substantial problem and that data limitations are rife. We use a case study of trophy hunting of an endangered antelope, the mountain nyala (Tragelaphus buxtoni), to explore how uncertainties generated by population monitoring and poaching interact with decision making by 2 key stakeholders: the safari companies and the government. We built a management strategy evaluation model that encompasses the population dynamics of mountain nyala, a monitoring model, and a company decision making model. We investigated scenarios of investment into antipoaching and monitoring by governments and safari companies. Harvest strategy was robust to the uncertainty in the population estimates obtained from monitoring, but poaching had a much stronger effect on quota and sustainability. Hence, reducing poaching is in the interests of companies wishing to increase the profitability of their enterprises, for example by engaging community members as game scouts. There is a threshold level of uncertainty in the population estimates beyond which the year-to-year variation in the trophy quota prevented planning by the safari companies. This suggests a role for government in ensuring that a baseline level of population monitoring is carried out such that this level is not exceeded. Our results illustrate the importance of considering the incentives of multiple stakeholders when designing frameworks for resource use and when designing management frameworks to address the particular sources of uncertainty that affect system sustainability most heavily. Incentivando el Monitoreo y el Cumplimiento en la Caza de Trofeos.
Although the main theoretical framework determining how to exploit populations was derived almost 50 years ago, overexploitation is common. I review 10 major concepts underlying the regulation of exploitation: population increase can be exploited; density dependence is essential; quantifying density dependence is exceedingly difficult; sustainable exploitation involves reducing population size; population growth rate is usually mismeasured; sustainability has many conflicting definitions and the choice depends upon the objectives; it is better to monitor the population than the harvest; quotas are unstable; increasing effort is simple, reducing it is painful; exploit conservatively. I then give a brief account of each of the nine main methods that are used to determine sustainable exploitation and the uses, advantages and limitations of each. The nine techniques are: surplus production models, yield per recruit models, Robinson and Redford model, linking yield to recruitment and mortality, adjusting to population changes, comparing demography across sites, reducing to a fixed fraction of unexploited population size, full population models and adaptive management.
It has been suggested that climatic variation has the effect on the dynamics of arid and semi-arid grazing systems of reducing animal numbers below the level at which they have much impact on vegetation or soils, and that spatial heterogeneity in resource availability serves to buffer herbivores against climatic variation. Modelling was used to test these hypotheses and to examine the interacting effects of temporal and spatial variability in plant production on animal population dynamics and defoliation intensity. The model distinguishes areas of the range that are accessible during wet and dry seasons, and examines the effect of seasonal restrictions in foraging area. It was established that the animal population is in long-term equi- librium with dry-season resources, on which it depends for survival; that dry season resource areas and outlying areas thus operate in a source-sink manner; and that the ratio of these areas determines the strength of consumer-resource coupling outside the dry-season range. A high ratio of dry season to wet season resources may support a sufficiently large animal population to impose non-trivial defoliation impacts on the outlying range. Increasing degrees of variability in primary production on areas used by animals for surviving the dry season increased the annual variation in animal abundance and reduced the mean. By comparison with a stable environment, for which the model predicts virtually stable animal numbers and constant, low defolia- tion intensity, variation in annual rainfall causes wide fluctuations in animal numbers and defoliation intensity. Under climatic variation, animal numbers can build up enough to impose much higher defoliation intensities than under a constant regime. Periodic intense defoliation is a consequence of climatic variability which is likely to make these environments more, not less, prone to ecological change.
The increasing isolation of protected areas poses a serious threat to the long-term viability of many wildlife populations and migrations in Africa. While ecologists have debated the impact of isolation on wildlife populations in reserves, field studies conducted over the past decade now provide a much clearer understanding of the effects. The primary drivers of isolation of protected areas are habitat loss, fences and roads, overhunting, and disease. These drivers restrict the movement of wildlife into and out of reserves and create sinks in the increasingly human-dominated matrix that surrounds most reserves. Post-establishment patterns of extinction of large mammal species in African reserves indicate that area and edge effects are important determinants of species persistence. Interactions and feedbacks between reserve isolation, human-related activities, and natural processes within and outside reserves can occur, yet are poorly understood. The problem of reserve isolation must therefore be addressed with a multi-pronged conservation strategy.
This book is available for purchase, The 1993 version is available on the page at http://distancesampling.org/downloads/distancebook1993/index.html
This article examines the effects of veterinary fences on wildlife populations in the Okavango Delta, Botswana. Using data from secondary data sources, findings indicate that the existence of veterinary fences in the Okavango Delta contributes to the decline of wildlife species in Botswana. Veterinary fences are erected to control the spread of livestock diseases in order to protect the European Union beef market where Botswana's beef is largely exported. Migratory wildlife species such as wildebeests, zebras, giraffes, buffalo, and tsessebes have their migratory routes blocked by veterinary fences and hence die from dehy- dration and entanglements in the fence. Those that get trapped by the fence often become easy kill targets for poachers. Some of the animals have been observed walking along the fence trying to cross. The erec- tion of veterinary fences indicates that the expansion of livestock production into wildlife areas threaten the survival of wildlife in Botswana. To address the problem, an integration of wildlife production with other sectors such as agricultural development should be made a priority at national and local policy levels. This means that the principles of sustainability should be given priority in the erection of veterinary fences in wildlife areas.
A majority of large mammals from Amboseli National Park rely on group ranch wildlife dispersal areas for wet season dispersal. However, the contraction of wildlife dispersal areas around Amboseli may be increasing, but the extent is unknown. This study investigated the contraction of wildlife dispersal area by human infrastructure in Olgulului – Ololorashi Group Ranch, which surrounds over 90% of Amboseli Park. Global Positioning System (GPS) was used for location and Geographical Information System (GIS) was used for spatial analysis to determine the area occupied by the structures. The minimum distance of wildlife kept away from institutions was 275 ± 20 m, followed by bomas (214 ± 16 m),roads (163 ± 9 m), and livestock (192 ± 12 m). The minimum distance of wildlife from human infrastructure was used as an index of wildlife displacement. All infrastructure occupied an actual area of 66 km2 (5%) of the group ranch. This increased to 281 km2 (23%) with wildlife displacement. Of the area occupied by human infrastructure, fourteen settlement clusters (199 km2, 10.82%) were located. Bomas covered 10% of the group ranch area, followed by institutions (6%), roads (5%), and agriculture (2.13%). The infrastructures were widely distributed in the group ranch and around the Amboseli. Although more dispersal space was available, the spatial distribution of clusters and infrastructure threaten wildlife dispersal. If the obstruction of dispersal routes is not addressed, the group ranch will be compromised as a wildlife dispersal area for Amboseli National Park.
More than 18% of tropical rainforests are now covered by totally protected areas. If these were well protected, we could feel reasonably confident that current conservation strategies might succeed in preserving a substantial proportion of tropical biodiversity. However, in most parts of the tropics, poachers enter and leave reserves with impunity. On the basis of reports from the hunting literature, it seems likely that a majority of tropical nature reserves may already be considered empty forests—meaning that all bird and mammal species larger than approximately two kilograms—barring a few hunting-tolerant species—have either been extirpated or exist at densities well below natural levels of abundance. The disruption of ecological functions caused by the loss of symbionts further compromises the capacity of these reserves to conserve biodiversity over the long term. A substantial shift toward improving the management and enforcement of tropical protected-area networks is required.
A database of approximately 9000 trophy measurements of ungulates hunted in South Africa between 1993 and 2001 was analysed in order to detect species-specific, regional variation in mean trophy quality. Blesbok (Damaliscus dorcas), eland (Taurotragus oryx), impala (Aepyceros melampus), kudu (Tragelaphus strepsiceros), mountain reedbuck (Redunca fulvorufula) and springbok (Antidorcas marsupialis) showed statistically significant variation in trophy quality. A number of other species including blue wildebeest (Connochaetus taurinus), black wildebeest (Connochaetus gnou), bushbuck (Tragelaphus angusticeps), common reedbuck (Redunca redunca), gemsbok (Oryx grazella), red hartebeest (Alcelaphus buselaphus), nyala (Tragelaphus angasit) and waterbuck (Kobus ellipsiprymnus) were insignificant. The manipulation of trophy quality on ranches is speculated to be the major cause of these significant regional variations. It is recommended that species-specific baselines of trophy quality and associated levels of acceptable manipulation be established and incorporated into a national trophy quality monitoring programme to provide some level of protection to an industry that contributes significantly to the South African economy.
We compared densities and distribution of wild ungulates and domestic livestock based on aerial surveys conducted during 1991 - 2010 in northern parts of Gonarezhou National Park (GNP), Zimbabwe. The sampled area covered approximately 320 km2 (Chipinda Pools area) representing ca. 27 % of the GNP, which was colonized by a few herder families along with their cattle in the year 2000. We hypothesized that (1) human and livestock encroachment in the park would lead to decline in densities of native ungulates, and (2) wild ungulates would avoid habitats influenced by humans. The results show that cattle densities significantly increased after the year 2000 whereas the densities of the native ungulates did not differ significantly after 2000. The ‘no change’ situation in herbivore populations is attributed to strict anti-poaching measures and restriction of human activities within small portion (4 %) of the park. However, the aerial survey does suggest that human and livestock presence in the northern GNP did influence the distribution of wild ungulates. Repeat observations during various seasons would be necessary to understand the spatio-temporal segregation among cattle and wild ungulates.
Globally, pressure from the illegal harvesting of wildlife is a recurrent issue for protected area management. In order to ensure the effective conservation of wildlife resources, law enforcement has been identified as one of the most important components of protected area management. Our study aimed at addressing the following two research questions: (1) what are the perceptions of law enforcement staff in Gonarezhou National Park (GNP), Zimbabwe, about illegal hunting practices, illegal hunter’s characteristics, wild animals commonly targeted and trends of poaching in the park; and, (2) what are the suggestions for reducing illegal hunting and enhancing wildlife conservation in GNP ecosystem? Data were collected using a semistructured questionnaire administered through interviews from 42 law enforcement staff representing 47 % of the total law enforcement staff in GNP from February to May 2011. Our results showed that 76 % (n = 32) of the patrol rangers perceived that most illegal hunters were between 21 and 30 years. Nearly all respondents (95 %; n = 40) reported that most poachers were residents of villages situated within 20 km from the boundary of GNP. Medium to large wild herbivores were reportedly the most illegally animal hunted species whilst large carnivores were the least illegally hunted animals. Most of the respondents (79 %, n = 33) perceived that poaching activities had declined in GNP ecosystem between 2005 and 2010 due to an increase in arrests. Increasing conservation awareness and education in adjacent communal areas would help to further reduce illegal hunting and promote wildlife conservation.
Illegal hunting of wildlife is a major issue in today’s society, particularly in tropical ecosystems. In this study, a total of 114 local residents from eight villages located in four wards adjacent to the northern Gonarezhou National Park, south-eastern Zimbabwe were interviewed in 2009, using semi-structured questionnaires. The study aimed to answer the following questions: (i) what is the prevalence of illegal hunting and what are commonly used hunting methods? (ii) Which wild animal species are commonly hunted illegally? (iii) What are the main reasons for illegal hunting? (iv) What strategies or mechanisms are currently in place to minimize illegal hunting? Overall, 59% of the respondents reported that they saw bushmeat, meat derived from wild animals, and/or wild animal products being sold at least once every six months, whereas 41% of the respondents reported that they had never seen bushmeat and/or wild animal products being sold in their villages and/or wards. About 18% of the respondents perceived that illegal hunting had increased between 2000 and 2008, whereas 62% of the respondents perceived that illegal hunting had declined, and 20% perceived that it remained the same. Snaring (79%) and hunting with dogs (53%) were reportedly the most common hunting methods. A total of 24 wild animal species were reportedly hunted, with African buffalo (Syncerus caffer) (18%), Burchell’s zebra (Equus quagga) (21%), kudu (Tragelaphus strepsiceros) (25%) and impala (Aepyceros melampus) (27%) amongst the most targeted and preferred animal species. In addition, large carnivores, including spotted hyena (Crocuta crocuta) (11%), leopard (Panthera pardus) (10%) and African lion (Panthera leo) (8%), were reportedly hunted illegally. The need for bushmeat, for household consumption (68%), and raising money through selling of wild animal products (55%) were reported as being the main reasons for illegal hunting. Strengthening law enforcement, increasing awareness and environmental education, and developing mechanisms to reduce human-wildlife conflicts will assist in further minimizing illegal hunting activities in the Gonarezhou ecosystem.
Droughts can have a severe impact on the dynamics of animal populations, particularly in semi-arid and arid environments where herbivore populations are strongly limited by resource availability. Increased drought intensity under projected climate change scenarios can be expected to reduce the viability of such populations, yet this impact has seldom been quantified. In this study, we aim to fill this gap and assess how the predicted worsening of droughts over the 21 st century is likely to impact the population dynamics of twelve ungulate species occurring in arid and semi-arid habitats. Our results provide support to the hypotheses that more sedentary, grazing and mixed feeding species will be put at high risk from future increases in drought intensity, suggesting that management intervention under these conditions should be targeted towards species possessing these traits. Predictive population models for all sedentary, grazing or mixed feeding species in our study show that their probability of extinction dramatically increases under future emissions scenarios, and that this extinction risk is greater for smaller populations than larger ones. Our study highlights the importance of quantifying the current and future impacts of increasing extreme natural events on populations and species in order to improve our ability to mitigate predicted biodiversity loss under climate change. Copyright: ß 2012 Duncan et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
In this article we show that the population of Serengeti Masai giraffes Giraffa camelopardalis tippelskirchi is extremely female biased, particularly among newborns. Our results suggest that this might be a response to heavy illegal hunting and the continuous disturbance such activities cause on giraffes, as sex ratios were more female skewed in all age groups in areas with high risk of illegal hunting. Giraffes were also more vigilant and fled at longer distances in such areas. Such female skewed sex ratios have also been found in other Serengeti species such as the ostrich Struthio camelus, the impala Aepycerus melampus and the wildebeest Connochaetus taurinus. In all studies, the sex ratio was more female skewed in areas in which illegal hunting is common. We found that sex ratio in giraffe calves, particularly in areas with high risk of illegal hunting, were more female skewed than in subadults or adults, indicating a female biased sex ratio at birth. If wildlife species react to a constant human disturbance by conceiving female offspring, this might cause serious conservation challenges. Conservation managers must anyway take this into account when developing future hunting regimes, not only for giraffes but also for other ungulate species under constant stress. We discuss various hypotheses aiming at explaining the female biased sex ratio in giraffes. However, further studies are needed to disentangle the causes of the skewed sex ratio observed in our study.
Moose Alces alces gigas in Alaska, USA, exhibit extreme sexual dimorphism, with adult males possessing large, elaborate antlers. Antler size and conformation are influenced by age, nutrition and genetics, and these bony structures serve to establish social rank and affect mating success. Population density, combined with anthropogenic effects such as harvest, is thought to influence antler size. Antler size increased as densities of moose decreased, ostensibly a density-dependent response related to enhanced nutrition at low densities. The vegetation type where moose were harvested also affected antler size, with the largest-antlered males occupying more open habitats. Hunts with guides occurred in areas with low moose density, minimized hunter interference and increased rates of success. Such hunts harvested moose with larger antler spreads than did non-guided hunts. Knowledge and abilities allowed guides to satisfy demands of trophy hunters, who are an integral part of the Alaskan economy. Heavy harvest by humans was also associated with decreased antler size of moose, probably via a downward shift in the age structure of the population resulting in younger males with smaller antlers. Nevertheless, density-dependence was more influential than effects of harvest on age structure in determining antler size of male moose. Indeed, antlers are likely under strong sexual selection, but we demonstrate that resource availability influenced the distribution of these sexually selected characters across the landscape. We argue that understanding population density in relation to carrying capacity (K) and the age structure of males is necessary to interpret potential consequences of harvest on the genetics of moose and other large herbivores. Our results provide researchers and managers with a better understanding of variables that affect the physical condition, antler size, and perhaps the genetic composition of populations, which may be useful in managing and modelling moose populations.
Hunting management of red deer Cervus elaphus populations may tend to increase population densities to maximise annual yield. Some studies have shown that density and low winter temperatures affect red deer populations in central and northern Europe, but these results cannot be extrapolated to red deer populations in the Mediterranean region where the limiting season is summer instead of winter. The two regions are predicted to experience different climate change effects: while rainfall may increase in northern latitudes, heavier droughts are expected in the Mediterranean region. We studied red deer populations of different densities on 19 hunting estates in southern Spain during two years with contrasting precipitation levels. Our aim was to quantify the combined effects of drought and population density on the development of stags, which is the main economic objective of hunting management in these areas. We found that drought affected body and antler size negatively, and that the effects were more severe in populations of high density. On the basis of our results, we recommend reducing the current densities of red deer in southern Spain to maintain the economic and environmental sustainability of hunting exploitation in the context of global climate change.
Throughout the world, terrestrial mammals arehunted for sport, subsistence and population con-trol, providing a significant source of meat and in-come to communities (Milner et al. 2007). ThegameranchingindustryinSouthAfricareliesheavilyontrophyhuntingasaprimary sourceofincome(duToit & van Rooyan 2002), and hence may be sub-ject to manipulation that could increase revenue.The industry is growing rapidly, and steps need tobetakentoensurethatthisindustryissustainable,and is firmly grounded in science with effectivegovernmentpolicy.InarecentarticleinSouthAfri-can Journal of Wildlife Research,von Brandis &Reilly(2008,hereaftervB&R)claimthatsignificantspatial variation exist in the trophy quality (a func-tion of horn size) of ungulates in South Africa andadvocate the importance of a national trophyquality monitoring programme in order to controlpotential manipulation of trophy populations.vB&R raise concerns over the extent of artificialselection being applied in the wildlife industry (seealso von Brandis & Reilly 2007). Although theseare important concerns within the game industrythat require attention, there are philosophical andmethodological limitations of this study that ques-tion its conclusions. Here we critically assess theanalytical approach and the conclusions of thatstudy.
A database of approximately 9000 trophy measurements of ungulates hunted in South Africa between 1993 and 2001 was analysed in order to detect monotonic trends in trophy quality over time. In a species-specific analysis, declines were found for impala (Aepyceros melampus), springbok (Antidorcas marsupialis) and mountain reedbuck (Redunca fulvorufula). In an area-specific analysis, a decline was found in the Northern Cape Province. Conversely, blesbok (Damaliscus dorcas phillipsi) (species-specific) and the Free State Province (area-specific) showed increases in trophy quality. As an economic indicator, the monitoring of trophy quality allows agencies to potentially evaluate the quality and sustainability of their 'huntable' ungulate resources.
The apparent increase in elephant Loxodonta africana numbers in northern Botswana is of concern because it may affect other species. We compared changes in population growth rates based on elephant numbers and densities over 1973–2004. Population estimates and survey details extracted from published and unpublished sources allowed us to calculate growth rates. From 1973 to 1993 growth rate was positive when based on elephant numbers but did not differ from zero when calculated for densities. This discrepancy may be because of the significant increase in survey area during the same period. In contrast, none of the growth rates differed from zero for time series between 1996 and 2004, when the size of the survey area varied little. We propose two explanations for these results. The first suggests that the population did not grow, while the second proposes that the population expanded its range and increased in size. Notwithstanding, an equilibrium model best explained the variance in dry season estimates of elephant numbers for the complete time series. Such apparent density-dependence could be disrupted by any artificial reduction of numbers through culling as a management option in northern Botswana.
The prevalence and impacts of the illegal trade in bushmeat are under appreciated in Southern Africa, despite indications that it constitutes a serious conservation threat in parts of the region. Bushmeat trade has emerged as a severe threat to wildlife conservation and the viability of wildlife-based land uses in Zimbabwe during a period of political instability and severe economic decline. We conducted a study around Savé Valley Conservancy in the South-East Lowveld of Zimbabwe to investigate the dynamics and underlying causes of the bushmeat trade, with the objective of developing solutions. We found that bushmeat hunting is conducted mainly by unemployed young men to generate cash income, used mostly to purchase food. Bushmeat is mainly sold to people with cash incomes in adjacent communal lands and population centres and is popular by virtue of its affordability and availability. Key drivers of the bushmeat trade in the South-East Lowveld include: poverty, unemployment and food shortages, settlement of wildlife areas by impoverished communities that provided open access to wildlife resources, failure to provide stakes for communities in wildlife-based land uses, absence of affordable protein sources other than illegally sourced bushmeat, inadequate investment in anti-poaching in areas remaining under wildlife management, and weak penal systems that do not provide sufficient deterrents to illegal bushmeat hunters. Each of these underlying causes needs to be addressed for the bushmeat trade to be tackled effectively. However, in the absence of political and economic stability, controlling illegal bushmeat hunting will remain extremely difficult and the future of wildlife-based land uses will remain bleak.
Context. Global climate change will lead to increased climate variability, including more frequent drought and heatwaves,
in many areas of the world. This will affect the distribution and numbers of wildlife populations. In south-west Queensland,
anecdotal reports indicated that a low density but significant koala population had been impacted by drought from
2001–2009, in accord with the predicted effects of climate change.
Aims. The study aimed to compare koala distribution and numbers in south-west Queensland in 2009 with pre-drought
estimates from 1995–1997.
Methods. Community surveys and faecal pellet surveys were used to assess koala distribution. Population densities were
estimated using the Faecal Standing Crop Method. From these densities, koala abundance in 10 habitat units was interpolated
across the study region. Bootstrapping was used to estimate standard error. Climate data and land clearing were examined as
possible explanations for changes in koala distribution and numbers between the two time periods.
Key results. Although there was only a minor change in distribution, there was an80%decline in koala numbers across the
study region, from a mean population of 59 000 in 1995 to 11 600 in 2009. Most summers between 2002 and 2007 were hotter
and drier than average. Vegetation clearance was greatest in the eastern third of the study region, with the majority of clearing
being in mixed eucalypt/acacia ecosystems and vegetation on elevated residuals.
Conclusions. Changes in the area of occupancy and numbers of koalas allowed us to conclude that drought significantly
reduced koala populations and that they contracted to critical riparian habitats. Land clearing in the eastern part of the region
may reduce the ability of koalas to move between habitats.
Implications. The increase in hotter and drier conditions expected with climate change will adversely affect koala
populations in south-west Queensland and may be similar in other wildlife species in arid and semiarid regions. The effect of
climate change on trailing edge populations may interact with habitat loss and fragmentation to increase extinction risks.
Monitoring wildlife population dynamics at the margins of their geographic ranges will help to manage the impacts of climate
change.
In some African protected areas, elephant populations have reached high densities causing concern about their influence on other forms of biodiversity, and in particular, other large herbivores. This has led to a debate whether management of elephant populations might need to be implemented. Surprisingly, few studies have focused on the influence of elephants on other herbivores and the existing results are conflicting. We investigated such influence in Hwange National Park, Zimbabwe, where elephants were culled and maintained at low density up to 1986, and have more than doubled since then, thus providing the opportunity to explore their possible influence on other herbivore species. Trends of different herbivore populations were obtained using long-term waterhole census data, with these results also being correlated to changes in dry season rainfall, as another fundamental determinant of herbivore population fluctuations. While our study did not allow us to properly disentangle the role of elephants and rainfall, it provided valuable insights. For five out of the 13 herbivore species studied, the population increased between 1973 and 1986 (high dry season rainfall; relatively low elephant abundance), then decreased between 1987 and 1995 (extremely low dry season rainfall; increase in the elephant population), and finally have increased since 1996 (high dry season rainfall; high elephant abundance). These results are consistent with an important role of dry season rainfall on herbivore population dynamics. Additionally, for four other species, the population increased between 1973 and 1986 and has decreased since then. As most herbivore declines occurred simultaneously with increase in the elephant population in the 1987–1995 period, and with the recent increase in most populations happening at a lower rate than the 1973–1985 period, our results suggest the possible existence of a negative influence of high elephant densities on other herbivores. We discuss what the possible underlying mechanisms can be and how to investigate them.
In the Katavi-Rukwa ecosystem of western Tanzania, aerial censuses carried out between 1988 and 2002 show that populations of several large ungulate species had declined. Five competing factors that could be responsible for these changes were investigated. (i) Rainfall increased slightly over 25 years and (ii) no obvious outbreaks of disease were witnessed, suggesting that populations are not suffering food shortages or disease. (iii) Large predators live at low densities and are not increasing, and estimates suggest that that predation is unlikely to impact larger prey species. (iv) Some assessments of illegal hunting indicate little influence on herbivore populations but one measure points to giraffe, hippopotamus, warthog and perhaps other species being adversely affected. (v) Tourist hunting quotas of lions and greater kudu in hunting blocks appear high and there are indications that both may be declining. Preliminary data, approximate calculations and elimination of hypotheses point to anthropogenic factors being partly responsible for changes in this ecosystem and constructive recommendations are made to alter these. More generally, this study highlights the importance of monitoring in conjunction with collecting diverse data when trying to stop population declines before they become too serious.
The rainfall pattern in time and space within the Masai Ecosystem of northern Tanzania was studied using rainfall data of sixteen stations within the area. Annual amounts of rainfall were found to be unpredictable, and the annual deviations of the long-term mean annual rainfall were without cyclic trends for the individual stations. However, the pooled rainfall data of the different stations show that series of wet and dry years alternate. Total annual rainfall increases with altitude and the variability in rainfall decreases with altitude. It appears that rainfall in the dry season is caused by thunderstorm activity, and no relation between rainfall and altitude exists during this time of the year. Rainfall in the wet season shows a very different spatial relationship, indicating the effects of the monsoon, and, especially during the long rains, rainfall increases with altitude. Different seasons can be discerned, and the data indicate that the amount of rain in the long rainy season is more predictable than the amount in the short rainy season. The differences are discussed briefly with regard to plant phenology patterns and grass growth.
We examined hypotheses regarding compatibility of managing white-tailed deer (Odocoileus virginianus) populations for trophy males (i.e., ≥8 points) and maximum sustained yield (MSY) harvests. Harvest of white-tailed deer on Oak Ridge Reservation, Tennessee, USA, began in 1985 following 45 years of protection. We examined several harvest characteristics (e.g., age and sex composition, antler and body size of males) under the assumption that the population had attained an equilibrium during this period and hunter bias toward males was constant across years. During 1985, 273 deer were killed by vehicles on the reservation; by 1994, mortality from vehicles declined to 143 deer. During the study period, annual harvest declined from 923 to 470 deer. We suspect that although the population had attained an equilibrium, it was likely below ecological carrying capacity (K) because of substantial vehicle mortality. Because of the absence of predators and other sources of natural mortality, we assumed that deer-vehicle collisions prior to hunting was the primary factor maintaining the population below K. After the initiation of hunting in 1985, several demographic parameters indicated the population was intensively harvested: 98% of the harvest was composed of males
Although long-term monitoring is viewed as an essential part of conserving wildlife populations, it is currently carried out in surprisingly few protected areas in Africa. Here, data from a 16-year vehicle transect monitoring programme in Katavi National Park, western Tanzania, are presented. These data provide information on large mammal densities, identify declines in populations of several large mammal species as based on encounter rates, support worrying trends observed in aerial census data and shed light on the effectiveness of recent changes in legal protection. Ground and aerial surveys confirmed that waterbuck, topi, warthog, lion and spotted hyaena populations are all in decline and that this should be a cause for concern. Counting animals by driving vehicle transects is relatively easy and inexpensive to carry out, and data here show that such counts have several pay-offs for conservation managers especially in identifying population declines; counts should be employed more often in East Africa and elsewhere.
The consumptive use of wildlife, in particular trophy hunting and game ranching of ungulates, has been advocated as a tool for conservation in Africa. We show that these methods of harvesting differ significantly from natural predation, with trophy hunting showing extreme selection for adult males and game ranching leading to disproportionate harvests of young males. Little information, either theoretical or empirical, exists concerning the effect of these harvesting regimes on the long-term population dynamics of ungulate populations. Despite that, the potential effects of sex-skewed harvests are numerous. In this paper, we investigate one potentially deleterious effect of sex-skewed harvests. Both theory and experimental data suggest that male ungulates are limited in their absolute ability to inseminate females. Using a Leslie-Matrix model and published data on impala, we show that the interaction between sperm limitation and harvests with highly male-biased sex ratios can lead to greatly reduced female fecundity (defined as the number of young born) and population collapse. These results are robust and suggest that present methods of harvesting may not be optimal, or viable, in the long term.
South Africa, as one of the most recognised trophy hunting destinations in the world, boasts a highly-developed, well-controlled, and professional hunting and game ranching industry (Radder & Han 2008). Despite past successes, providers of the hunting safari are challenged by the global economic downturn, negative public perception due to a few individuals' involvement in put-and-take and canned hunting practices (Von Brandis & Reilly 2007) and claims by anti-hunting groups (MacKay & Campbell 2004).
Providing satisfying hunting experiences could enhance the industry's chances of continued success. Satisfaction is an important source of competitive advantage (Ritchie & Crouch 2000) in so far as it affects tourists' expectations, intentions for future purchase (Akama & Kieti 2003), decisions to return to the destination (Kozak & Rimmington 2000) or spreading positive word-of-mouth (Huo & Miller 2007).
Conventionally, tourist satisfaction is measured by importance-performance models (Deng 2007); SERVQUAL (Williams 1998); and SERVPERF (Yoon & Uysal 2005). Much debate ensued about the usefulness of the above approaches (Carrillat et al 2007) particularly in measuring tourist satisfaction with an entire holiday at a specific destination (Truong & Foster 2006), Tribe and Snaith (1998) initiated, and Truong and Foster (2006) further developed the HOLSAT instrument to overcome some of the other models' caveats. Given the complexity and multitude of components comprising the safari hunt; the variety of service providers, ranging from travel agents, airport staff, outfitters, professional hunters, trackers, skinners and taxidermists involved in the total experience; and the uniqueness of South Africa as a hunting destination, an adapted HOLSAT model was used to determine safari hunters' satisfaction with their South African experience. This paper reports the results.
Trophy hunting in ungulates may favour individuals with smaller horns. A decrease in horn/antler size may jeopardize the conservation potential of hunting areas, which would be a major concern in Africa where hunting zones represent over half of the total area of protected lands. We investigated horn length trends of harvested male impalas Aepyceros melampus, greater kudus Tragelaphus strepsiceros and sable antelopes Hippotragus niger, from 1974 to 2008 in Matetsi Safari Area, Zimbabwe. Horn length declined by 4% in impalas, partly because male harvest age decreased. In greater kudus, surprisingly, horn length increased by 14%, while mean age of harvested male greater kudus increased during the study period. Reduced hunting pressure on this species during the study may have allowed males to live longer and to grow longer horns before being harvested. Horn length declined by 6% in sable antelopes, independent of age, suggesting that trophy hunting selected male sable antelopes with smaller horns through time, provided that horn length is heritable. Hunting pressure and trophy value were higher for sable antelopes than for impalas and greater kudus. Accordingly, the decline of horn length in this species was more pronounced. More valuable trophy species, such as sable antelopes, require special attention because they may be exposed to higher hunting pressure, and are therefore more likely to experience a decrease in horn size.
Hunting is one of the greatest conservation challenges facing tropical wildlife. Wildlife in Indian tropical forests are vulnerable to hunting, although data on hunting impacts from the region are limited. We use a meta-analysis of 143 hunting studies from India to identify the species and geographic regions most at risk, and to assess their legal protection. We found evidence of hunting in 114 mammal species, with larger-bodied mammals being particularly vulnerable. Although 75% of all studies focused on mammals, few actually quantified hunting impacts. Further, among studies of all terrestrial vertebrates where hunting was mentioned, only 6% focused exclusively on hunting. With further research, we expect that the suite of species known to be exploited by hunters will increase. We conclude that the Eastern Himalaya and Indo-Myanmar biodiversity-hotspot complex is particularly vulnerable to hunting. Quantitative studies of hunting impacts are urgently needed across India, especially in this biodiversity-hotspot complex.
In Tanzania, where tourist hunting is employed as a conservation tool for habitat protection, information on population sizes and hunting offtake was used to assess the impact of tourist hunting on mammal densities. In general, tourist hunting pressure was unrelated to local population sizes, but for most species, animals were removed at a level of less than 10% of the local population size, suggesting that over-exploitation was unlikely. Eland, however, and perhaps small antelope, bushbuck, kudu and reedbuck were hunted at levels which may be unsustainable in the long term. Analyses also identified areas of Tanzania with high levels of tourist hunting pressure, showed that, in certain areas, species with small population sizes such as eland could be declining as a result of tourist hunting, and suggested that current levels of lion and leopard offtake are too high. These findings, although preliminary, allow recommendations to be put forward for changing hunting quotas for certain species in particular areas of Tanzania.
Illegal hunting of wildlife, or top-down harvesting, is a major issue in today's society, particularly in tropical ecosystems. There has been widespread concern about increasing illegal hunting of wildlife in most conservation areas in Zimbabwe following the political instability and economic decline the country faced since 2000. In this study, we focused on the northern Gonarezhou National Park (GNP), a large and unfenced protected area, and adjacent communal areas in southern Zimbabwe. We hypothesised that illegal hunting activities would (1) be perceived to have increased due to economic collapse and (2) vary with law enforcement efforts. A total of 236 local residents from eight villages adjacent to the northern GNP were interviewed using semi-structured questionnaires from December 2010 to May 2011, and law enforcement data for northern GNP between 2000 and 2010 were retrieved from the park law enforcement database. A total of 26 animal species were reportedly hunted. Bushmeat consumption and the need for local trade to raise income were reported as the main reasons behind illegal hunting. Contrary to the first hypothesis, the majority of respondents (n = 156, 66%) reported that illegal hunting activities had declined between 2000 and 2010 largely due to increased park protection as also supported by law enforcement data. A total of 22 animal species were recorded as having been illegally hunted in northern GNP. The number of illegal hunters arrested declined with increased law enforcement efforts although the number of wire snares recovered and hunting dogs shot appeared to increase following increased law enforcement efforts. These results partly support the second hypothesis that illegal hunting activities would vary with law enforcement efforts.
In the Katavi-Rukwa ecosystem of western Tanzania, aerial censuses carried out between 1988 and 2002 show that populations of several large ungulate species had declined. Five competing factors that could be responsible for these changes were investigated. (i) Rainfall increased slightly over 25 years and (ii) no obvious outbreaks of disease were witnessed, suggesting that populations are not suffering food shortages or disease. (iii) Large predators live at low densities and are not increasing, and estimates suggest that that predation is unlikely to impact larger prey species. (iv) Some assessments of illegal hunting indicate little influence on herbivore populations but one measure points to giraffe, hippopotamus, warthog and perhaps other species being adversely affected. (v) Tourist hunting quotas of lions and greater kudu in hunting blocks appear high and there are indications that both may be declining. Preliminary data, approximate calculations and elimination of hypotheses point to anthropogenic factors being partly responsible for changes in this ecosystem and constructive recommendations are made to alter these. More generally, this study highlights the importance of monitoring in conjunction with collecting diverse data when trying to stop population declines before they become too serious.
In Kenya knowledge of the relative severity of threats to protected areas and the vulnerability of these areas to any threats is lacking. Such information is required, however, for assessment of the effectiveness of management of the country’s protected areas, and to help identify critical management and policy weaknesses and priorities for improving management and allocating resources. We therefore studied the relative severity of threats to Kenya’s 50 protected areas and their relative vulnerability to such threats based on the perceptions of protected area managers. Ten threats were identified by these managers, of which the most severe were illegal bushmeat hunting, poaching of large mammals, human–wildlife conflicts, human encroachment, and loss of migration corridors and dispersal areas. Thirty-two (64%) protected areas were vulnerable to over half of the threats, 54% vulnerable to over six of the threats and 32% vulnerable to over seven of the threats. Protected areas in marine, forested/montane and inland wetland ecosystems were regarded as highly vulnerable to the perceived threats. Protected areas adjacent to urban/industrial and agricultural areas were vulnerable to most of the threats. Our findings demonstrate that protected areas in Kenya are increasingly threatened, that major threats needs to be mitigated, and that prioritization of protected areas for strategic actions is required for effective management.
Data on densities, biomass and ecological factors governing the distribution of various wild ungulate species in the difFerent management units of Gir forest from 1987 to 1989 were collected. Density of ungulates ranged from 50.8 km−2 to 0.42 km−2, the highest for chital (Axis axis), followed by chinkara (Gazella gazella), sambar (Cervus unicolor), nilgai (Boselaphus tragocamelus) and chowsingha (Tetracerus quadricornis). The density of chital did not vary significantly between different censuses and management units. The wild ungulate biomass ranged from 3290 kg km−2 in the National Park to 1900 kg km−2 in the Sanctuary East. Following the partial removal of people and livestock in the mid-1970s, there was an increase in the population of all wild ungulates except nilgai and wild pig (Sus scrofa). Concurrently, there was an increase in the proportion of wild ungulate prey in the lion's diet. Chital density has shown a 1320% increase. An increase in suitable habitats and a decrease in direct competition with livestock are the most likely factors to have triggered the eruption in chital population. These density estimates are discussed in relation to the prevailing ecological conditions in different management units of Gir.
Populations of many wild ungulate species in Africa are in decline largely because of land-use changes and other human activities. Analyses that document these declines and advance our understanding of their underlying causes are fundamental to effective management and conservation of wild ungulates. We analyzed temporal trends in wildlife and livestock population abundances in the Mara region of Kenya. We found that wildlife populations in the Mara region declined progressively after 1977, with few exceptions. Populations of almost all wildlife species have declined to a third or less of their former abundance both in the protected Masai Mara National Reserve and in the adjoining pastoral ranches. Human influences appeared to be the fundamental cause. Besides reinforced anti-poaching patrols, the expansion of cultivation, settlements and fences and livestock stocking levels on the pastoral ranches need to be regulated to avoid further declines in the wildlife resource.