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1.
Illegal hunting poses a dual threat to large carnivores through direct removal of individuals and by prey depletion. We conducted a camera-trapping survey in the Namdapha National Park, north-east India, conducted as part of a programme to evaluate carnivore and prey species abundance. Clouded leopard (Neofelis nebulosa) was the only large carnivore detected by camera-trapping. Indirect evidences indicated the presence of the wild dog (Cuon alpinus) and leopard (Panthera pardus), however, there was no evidence of tigers (Panthera tigris), suggesting their possible extinction from the lower elevation forests. Of the major ungulate prey species, sambar (Cervus unicolor) and wild pig (Sus scrofa) were the only large prey detected, while the Indian muntjac (Muntiacus muntjak) was the only small prey species detected. Relative abundances of all species were appreciably lower than estimates from other tropical forests in south-east Asia. We suspect that illegal hunting may be the cause for the low carnivore and prey species abundance. An ongoing community-based conservation programme presents an opportunity to reduce local people’s dependence on hunting by addressing their socio-economic needs and for using their skills and knowledge of the landscape for wildlife conservation. However, long-term wildlife monitoring is essential to assess the efficacy of the socio-economic interventions in bringing about wildlife recovery.  相似文献   

2.
Most large mammalian carnivores are in global decline, largely due to their involvement in livestock depredation. Research that advances our understanding of predator-livestock interactions is crucial to conflict mitigation and carnivore conservation. Here we investigated the influence of environmental and socio-ecological factors on livestock depredation by carnivores in pastoral villages adjacent to the Maasai Mara National Reserve, Kenya during a 14-month period. We attempted to identify factors associated with temporal and spatial variation in depredation rates, incorporating data on a closely monitored spotted hyena (Crocuta crocuta) population known to be involved in depredation events. Spotted hyenas, leopards (Panthera pardus) and lions (Panthera leo) were responsible for 53%, 32%, and 15% of attacks on livestock, respectively. Monthly depredation frequency was correlated positively with rainfall and negatively with natural prey abundance. Radio-telemetry revealed that hyenas defending a group territory within the Reserve spent more time outside the Reserve during months when hyena attacks on livestock were most frequent. Results of logistic regression models, which indicated spotted hyenas were most likely to attack large villages, were supported by behavioral observations of hyenas near villages. Leopards however, selected villages that were spatially isolated from other villages. Hyenas were more likely to attack livestock enclosures constructed of local bush material than those of more sturdy “pole” timber, but use of pole material more than doubled the probability of leopard attack. Selection of fence type should therefore depend on the size and relative isolation of villages. Overall, improved fences, more watch dogs, and high levels of human activity were not associated with lower livestock losses to predators.  相似文献   

3.
Lions (Panthera leo) are in decline throughout most of their range due to human persecution, largely provoked by depredation on livestock, and there is debate as to the usefulness of financial instruments to mitigate this conflict. Intending to reduce local lion-killing, the Mbirikani Predator Compensation Fund compensates members of Mbirikani Group Ranch for livestock depredation at a flat rate (close to average market value), after the kill has been verified and with penalties imposed for poor husbandry. Despite penalizing claimants, 55% of claims arose because livestock were lost in the bush. Between 1st April 2003 and 31st December 2006, 754 cattle, 80 donkeys and 1844 sheep/goats were killed (2.31% of the total livestock herd each year). Forty-three percent of kills were ascribed to spotted hyaenas (Crocuta crocuta); leopards (Panthera pardus) and cheetahs (Acinonyx jubatus) were blamed for 37% of cases, lions 7%, jackals (Canis mesomelas) 7% and buffalo (Syncerus caffer) and elephants (Loxodonta africana) together 6%. Significantly more attacks took place during months of lower rainfall but the rate of attacks was not related to the density of livestock on the ranch, or the ratio of wild herbivores to domestic stock. There was no correlation between local market prices and the number of claims per month. Despite compensation, at least one lion per year was killed in 2004, 2005 and 2006. We describe some features of large carnivore depredation in the study area and suggest that regional recovery of the lion population may require compensation on a wider scale.  相似文献   

4.
The fish fauna of mountain streams in the Jiri (440 km2) and Seorak (373 km2) National Park areas of South Korea was investigated from September 1998 to May 2001. A total of 5979 fish were collected and classified into 22 families and 60 species from both national parks. At Jiri, 30 species in 12 families of fishes were collected, while at Seorak there were 42 species in 17 families. Zacco temmincki [relative abundance (RA) 47.9%] was dominant at both parks. Subdominant species were Rhynchocypris kumkangensis (RA 10.8%), Zacco platypus (RA 9.4%), and Pungtungia herzi (RA 5.3%). A total of 20 species were found to be Korean endemic species, representing seven families. The relative abundance of Korean endemic species was higher at Seorak (30.5%) than Jiri (18.5%). One exotic species (Oncorhynchus mykiss) and two species translocated outside their native catchments (Hypomesus nipponensis and Coreoperca herzi) were collected. The proportion of Korean endemic freshwater fish species in both parks (33.3%) was higher than the overall proportion on the Korean peninsula (23.6%). Within the 14 South Korean mountain-area national parks as a whole, larger parks tend to have higher fish diversity. We conclude that South Korean national parks are important for conservation of the regional fish fauna, especially for endemic and endangered species. Current threats to conservation of fishes within South Korean national parks are identified and management solutions are suggested.  相似文献   

5.
Human-carnivore conflict is a serious management issue often causing opposition towards conservation efforts. In a survey of 481 households in seven different villages outside the Serengeti National Park in Tanzania, 67.4% of respondents owned livestock and 27.4% of all the households surveyed reported losses of a total of 4.5% of their livestock to wild predators over 12 months. This loss equated to an average annual financial loss of 19.2% (US $26.8) of their cash income. Livestock depredation was reported to be caused most often by spotted hyena (Crocuta crocuta) (97.7%), leopard (Panthera pardus) (1.6%), baboon (Papio cynocephalus) (0.4%), lion (Panthera leo) (0.1%) and lastly black-backed jackal (Canis mesomelas) (0.1%). Total reported losses during 2003 amounted to US $12,846 of which spotted hyena kills were reported to account for 98.2%. The mean annual livestock loss per household (of those that reported loss) was 5.3 head of stock, which represents more than two-thirds of the local average annual cash income. Depredation by large felids occurred only in a narrow zone along the protected area (<3 km), whereas spotted hyenas killed livestock even in households located far away (>30 km). Tolerance of livestock depredation among the respondents was low. Logistic regression models indicated that education improved tolerance, while for livestock owners higher depredation rates was linked to approval of lethal retaliation and effective protection measures was associated with a reduced desire of retaliation. We recommend that further research should identify the precise causes of livestock loss and which protection measures that can reduce depredation.  相似文献   

6.
Domestic dogs (Canis familiaris) arrived in Zimbabwe ca. 1000 years ago. Numbers of free-ranging dogs have reached unprecedented levels in communal lands (agro-pastoralist rural areas), and interact with large wild carnivores along boundaries with wildlife reserves as predators and prey. This study examined a population of 236 dogs in a 33-km2 section of Gokwe Communal Land (GCL) bordering the Sengwa Wildlife Research Area (SWRA) in north-western Zimbabwe in 1995-1996. Dogs were found up to 6 km within the SWRA, and were the most common carnivore on the GCL-SWRA boundary. Observations of 16 radio-collared dogs showed that they were inefficient predators. Only 20 kills were recorded amongst the remaining dog population, of which three were wild ungulates. Dogs were unsuccessful predators due to their small group size (mean 1.7) and body mass (mean 14.7 kg), and the abundance of alternative food. It is therefore unlikely that they compete with large carnivores for wild prey. However, leopards (Panthera pardus), lions (P. leo) and spotted hyaenas (Crocuta crocuta) preyed on dogs in GCL, removing ?6% of the dog population in 1993. Such predation provides ideal circumstances for disease transmission. Canid disease was prevalent in the study area; including rabies and probably distemper. The risk of infection is greatest during the dry season (May-October), when peaks in rates of disease, carnivore incursions into GCL, and predation on dogs coincided. The role of jackals (Canis adustus and Canis mesomelas) and spotted hyaena predation of dogs is discussed in relation to disease epidemics within wildlife reserves. With a dog population growth rate of 6.5% per annum, and the prevalence of canid diseases, the conservation threat posed by dogs is escalating on communal land-wildlife reserve boundaries in Zimbabwe. Measures to control dog numbers and improve vaccination coverage of dogs are discussed.  相似文献   

7.
Exploitation of wildlife for meat in the tropics (‘bushmeat’) is a critical threat for biodiversity, particularly in Africa. Here, we investigate the importance of protected areas (National Parks and other forest parks) as sources for the trade by exploring patterns in pricing and condition of bushmeat carcasses. We surveyed carcass prices in a large sample of trading points (87 markets surveyed, over a 35,000 km2 area) in Cameroon and Nigeria in the Cross–Sanaga region of West Africa. We assessed evidence for national parks as the source of animals traded as bushmeat. The study area included rural and urban centers (Calabar, Nigeria, and Douala, Cameroon) close to important protected areas: the Cross River National Park in Nigeria, and Korup National Park in Cameroon. Both parks host very high species diversity, including a range of endemics. Prices increased with distance from national park boundaries, particularly in Cameroon, where parks may be less depleted than in Nigeria. There was evidence that trading points closer to parks were more likely to function as wholesalers, with meat moving onto further trading points, rather than being sold to the end consumer. Carcasses were more often smoked (a treatment aimed at preservation) if they were not sold to their final consumers; smoking was also commoner at larger trading points. Prices were higher close to the road network, where opportunities for further trade were more available. We consider how wildlife harvests in and around protected areas may be managed to minimize depletion of animal populations, and if protected areas may, on the principle of marine no-take zones, be sustainable sources for regulated harvests.  相似文献   

8.
Interest in bean genetic resources of Central America has resumed because of disease pressures (e.g., web blight, BGMV) and limitations of current bean varieties. As most of the diversity in landraces has been explored, focus is now on the exploration of wild forms of the primary gene pool and wild species of the secondary gene pool. A germplasm collection was carried out in the field and resulted in the collection of 29 wild populations for six Phaseolus species; it complemented field work done in 1987. Nine more populations were found for P. costaricensis, 10 for wild P. lunatus, one for P. oligospermus, one for P. tuerckheimii, four for wild P. vulgaris and four for P. xanthotrichus. Ninety-three herbarium voucher specimens were collected for 19 populations of the six species (deposited at CR). These results confirm the presence of wild P. vulgaris on both slopes of the central valley of Costa Rica, namely in the life zones bh-MB and bmh-P, and of P. costaricensis in the life zone bmh-MB. These life zones of limited range in Costa Rica have been heavily modified, thus fully justifying the germplasm collection for ex situ conservation. For both species the range of distribution in Costa Rica has been almost completely sampled. The life characteristics of each species that are relevant for their conservation in situ are briefly reviewed. Distribution ranges of each wild bean species are compared with the present extension of national parks, protected areas and fauna/flora sanctuaries, and suggestions for expanding such protected areas are made.  相似文献   

9.
Wild meat harvests in African moist forests are presumed to exceed production, even in the case of traditional societies still using rudimentary hunting methods. Though some approximations do exist of the volume of bushmeat harvested in some Central African moist forest areas, estimates based on extensive and simultaneous sampling, within a large geographical region, are not available. Here, we present the results of the first reported study of this kind. During a period of 5 month, we counted bushmeat carcasses deposited in 89 urban and rural markets in a 35,000 km2 area between the Cross River in Nigeria and the Sanaga River in Cameroon. We used these data to calculate annual bushmeat volume traded by site, species and overall in the study area.Mammals represented >90% of the bushmeat carcasses sold in all sites. Reptiles were also abundant, but birds and amphibians were relatively scarce. Estimates of carcasses extracted and crude biomass per site varied significantly between countries. In Nigeria, biomass (kg) extracted for sale per km2 per year, was three times greater (600 kg/km2) than in Cameroon. Conservative estimates for the entire study area indicate that >900,000 reptiles, birds and mammals are sold each year by the rural and urban population, corresponding to around 12,000 tonnes of terrestrial vertebrates. We also assessed the relationship between bushmeat harvested for sale and distance of the study settlements from the main protected areas (Cross River and Korup National Parks). The number of carcasses and biomass sold was negatively related to the proximity to the national parks in >50% of species in Nigeria, and in 40% of species in Cameroon.Our cross-site comparison documents the staggering volume of wild species affected by hunting in the region. We also conclude that species within the main protected areas in both countries are likely to be negatively affected by the current and future demand for bushmeat in the surrounding areas.  相似文献   

10.
Human exploitation can have severe conservation implications for wildlife populations. In the Serengeti ecosystem, Tanzania, illegal hunting is a serious concern for wildlife management, and in this study we investigated if density, demography and behaviour can be used as indicators of human exploitation. We used impala (Aepycerus melampus) as a model species to study human exploitation inside and outside a strictly protected area. Over a six month period, a total of 2050 km of transects were driven in the different protected areas (National Park, Game Reserve, Open Area). Densities were estimated by using distance sampling and the partially protected areas were found to have significantly lower densities (4.3 ind/km2) than the National Park (15.3 ind/km2). A variation in density between different sections within the National Park was also found. However, we found no differences in group sizes. Moreover, the sex-ratio was more skewed towards females in the partially protected areas and in sections within the National Park close to villages. In addition, impalas showed higher alertness levels, and longer flight initiation distance to an approaching human in the partially protected areas compared to the National Park. The present harvest levels by illegal hunting in the study area are most likely the cause of the observed differences. Our results suggest that density, demography and behaviour can be used as indicators of human exploitation, but that this probably varies according to local hunting pressure. Furthermore, it could be expected that the results obtained in this study might reflect the state of other ungulates in the area, which raises concern whether management objectives for the buffer zones of Serengeti National Park are met.  相似文献   

11.
The impact of hunting on wildlife is a complex phenomenon which varies in space and across time, and yet limited knowledge is available on it. This is especially the case of the indirect effects of hunting on the behaviour of target as well as non-target species. Here we analyze how hunting affected the spatial behaviour of 62 radiocollared roe deer (Capreolus capreolus) in a protected area adjacent to areas where hunting with hounds (target species: wild boar and hares) and stalking with rifles from high seats without dogs (target species: roe deer) were permitted during the hunting season. Our results showed that hunting caused a significant increase in the home range size of monitored deer, as well as a “reserve effect”, whereby roe deer used the protected area as a refuge from hunters. These behavioural responses were significant only at times when hunting with hounds was conducted, even though roe deer was not the target species of this technique. Reactions to the perceived risk of predation varied among age and sex classes, with yearling being more sensitive and using the protected area more than adults. As shown in our study, hunting harassment provoked by drives with hounds significantly affects the behaviour of non-target species. Therefore, the use of long-legged hounds represents a variable that should be carefully evaluated by wildlife managers in their management plans and conservation policies, especially when endangered or vulnerable species are present.  相似文献   

12.
Interactions among sympatric large predators and their prey and how they respond to conservation measures are poorly known. This study examines predictions concerning the effects of establishing a protected area in Nepal on tigers (Panthera tigris), leopards (Panthera pardus), and their ungulate prey. Within a part of the park, after 22 years the total density of wild ungulates had increased fourfold, to ca. 200 animals/km2, almost exclusively due to a remarkable increase in chital deer (Axis axis). Tiger density also increased markedly to nearly 20 animals/100 km2, whereas leopard density did not and was ca. 5 animals/100 km2. The prediction that grazers should increase more than browsers was only partially supported. The prediction of positive density dependence in prey selection was not supported. Instead, the most abundant species (chital and hog deer, Axis porcinus) were killed less frequently than expected, whereas the lower-density wild boar (Sus scrofa) was preferred. Predictions that (i) initially rare species suffer highest predation was partially supported, that (ii) predation is highest among the most abundant prey was not supported, and that (iii) predation is highest among the most preferred prey independently of their densities was supported. Clearly, the conservation efforts adopted in Bardia were successful, as both tigers and their natural prey base increased. However, the positive numerical response of tigers limited and depressed the abundance of some prey species. Thus, conservation activities aimed at restoring large predators are likely to change in the composition of the overall mammal community, potentially eliminating rare but preferred prey species.  相似文献   

13.
Large ungulate populations in Southeast Asia have collapsed due to commercial poaching, but little is known about patterns of population recovery after poaching has been controlled. Using a sign-based index of abundance, we measured 6-year trends in abundance and habitat use of five ungulate species after poaching ceased at a site in Thailand. Regression slopes of annual indices against time indicated population growth rates (r) of 0.44 and 0.31 for muntjac (Muntiacus muntjak) and gaur (Bos gaurus), respectively—close to the intrinsic rates of natural increase for similarly-sized ungulates. Thus, muntjac and gaur can recover relatively rapidly from low population levels. In contrast, sambar (Cervus unicolor) remained consistently rare despite freedom from hunting, perhaps because prime males had been selectively targeted for trophies, disrupting the species mating system. Wild pigs (Sus scrofa) were already relatively abundant when monitoring started, illustrating their resilience to hunting and ability to quickly recolonize disturbed areas. Gaur herds (the key demographic unit of the population) and muntjac consistently selected deciduous over evergreen forest as their populations increased, revealing the importance of food-rich deciduous forest in driving recovery of these species. The unexpected failure of sambar to recover suggests that reproductive behavior may override seemingly positive interventions (i.e., stopping poaching) that reduce mortality. Small but well-protected recovery zones set within forested areas might help propel population recovery of ungulates and increase the prey base for endangered tigers.  相似文献   

14.
Increasing the level of protection afforded to the marine environment requires assessment of the efficacy of existing marine protected areas (MPAs) in protecting exploited species. Long-term data from before and after the establishment of MPAs provide a rare but valuable opportunity to assess these effects. In this study we present long-term data (1977-2005) from before and after park establishment, on the abundance of spiny lobster Jasus edwardsii from fixed sites in a no-take marine park and a recreationally fished marine park, to assess the efficacy of no-take vs. partial protection. Lobster densities were comparable between both marine parks prior to park establishment, but the response of lobster populations differed markedly following protection. On average, legal-sized lobster were eleven times more abundant and biomass 25 times higher in the no-take marine park following park establishment, while in the partially protected marine park there has been no significant change in lobster numbers. Furthermore, no difference was found in densities of legal-sized lobster between the partially protected marine park and nearby fully-fished sites (<1 per 500 m2). Long-term data from fully fished and partially protected sites suggest long-term declines in lobster populations and reflect regional patterns in catch per unit effort estimates for the fishery. The long-term patterns presented provide an unequivocal example of the recovery of lobster populations in no-take MPAs, but clearly demonstrate that allowing recreational fishing in MPAs has little benefit to populations of exploited species such as J. edwardsii.  相似文献   

15.
The northern spotted owl (Strix occidentalis caurina) is a controversial species in the Pacific Northwest that is listed as threatened under the Endangered Species Act. The barred owl (Strix varia), a species historically restricted to eastern North America, has recently expanded its range to completely overlap that of the northern spotted owl. Recent evidence suggests that barred owls may compete with northern spotted owls and may be one cause for recent declines in some northern spotted owl populations. Our focus was to examine whether barred owls have the potential to competitively exclude northern spotted owls from their territories through interference competition. We used a playback experiment to quantify aggressive vocal and physical behavior of barred and northern spotted owls during territorial defense. Experimental trials consisted of displaying northern spotted or barred owl taxidermy mounts, and broadcasting recorded vocalizations of the corresponding species, in both barred and northern spotted owl territories. The frequency of interspecific interactions was lower compared to intraspecific interactions between northern spotted owls alone. However, barred owls responded with higher levels of vocal and physical aggression than did northern spotted owls when agonistic interspecific interactions occurred. Our results suggest that barred owls are likely to assume the dominant role during interspecific interactions with northern spotted owls. Thus, interference competition is a plausible mechanism by which barred owls could contribute to observed population declines of northern spotted owls in areas where the species co-occur.  相似文献   

16.
Large predators potentially can help shape the structure and functioning of terrestrial ecosystems, yet strong evidence of top-down herbivore limitation has not been widely reported in the scientific literature. Herein we synthesize outcomes of recent tri-trophic cascades studies involving the presence and absence of large predators for five national parks in the western United States, including Olympic, Yosemite, Yellowstone, Zion, and Wind Cave. Historical observations by park biologists regarding woody browse species and recently compiled age structure data for deciduous trees indicate major impacts to woody plant communities by ungulates following the extirpation or displacement of large predators. Declines in long-term tree recruitment indexed additional effects to plant communities and ecological processes, as well as shifts towards alternative ecosystem states. The magnitude and consistency of vegetation impacts found within these five parks, in conjunction with other recent North American studies, indicate that broad changes to ecosystem processes and the lower trophic level may have occurred in other parts of the western United States where large predators have been extirpated or displaced. Thus, where ungulates have significantly altered native plant communities in the absence of large predators, restoration of native flora is urgently needed to recover former ecosystem services. Following the reintroduction of previously extirpated gray wolves Canis lupus into Yellowstone National Park, a spatially patchy recovery of woody browse species (e.g., aspen Populus tremuloides, willow Salix spp., cottonwood Populus spp.) has begun, indicating that large predator recovery may represent an important restoration strategy for ecosystems degraded by wild ungulates.  相似文献   

17.
We apply an age- and stage-structured model incorporating varying harem sizes, paternal care and infanticide to examine the effect of hunting on sustainability of populations. Compared to standard carnivore and herbivore models, these models produce different outcomes for sustainable offtake when either adults, or adult males are harvested. Larger harem size increases sustainable offtake whereas paternal care and infanticide lowers it. Where males are monogamous, populations are vulnerable to male offtake, regardless of paternal care. Surprisingly, an incidental take of 10% of other age-sex-classes has very little effect on these findings. Indiscriminate (subsistence) hunting of all age-sex classes has a dramatic effect on certain populations. Applying these behavior-sensitive models to tourist hunting in the Selous Game Reserve, Tanzania, we find that across the Reserve hunting quotas were generally set at sustainable rates except for leopard (Panthera pardus). In certain hunting blocks within the Reserve, however, quotas for eland (Taurotragus oryx), hartebeest (Alcelaphus buselaphus), lion (Panthera leo), reedbuck (Redunca arundinum), sable antelope (Hippotragus niger), warthog (Phacochoerus aethiopicus) and waterbuck (Kobus ellipsiprymnus) are set at unsustainably high rates. Moreover, particular blocks are consistently awarded high quotas. Behaviorally sensitive models refine predictions for population viability, specify data required to make predictions robust, and demonstrate the necessity of incorporating behavioral ecological knowledge in conservation and management.  相似文献   

18.
Large mammal faunas in tropical forest landscapes are widely affected by habitat fragmentation and hunting, yet the environmental determinants of their patterns of abundance remain poorly understood at large spatial scales. We analysed population abundance and biomass of 31 species of medium to large-bodied mammal species at 38 Atlantic forest sites (including three islands, 26 forest fragments and six continuous forest sites) as related to forest type, level of hunting pressure and forest fragment size using ANCOVAs. We also derived a novel measure of mammal conservation importance for each site based on a “Mammalian Conservation Priority index” (MPi) which incorporates information on species richness, population abundance, body size distribution, conservation status, and forest patch area. Mammal abundance was affected by hunting pressure, whereas mammalian biomass of which was largely driven by ungulates, was significantly influenced by both forest type and hunting pressure. The MPi index, when separated into its two main components (i.e. site forest area and species-based conservation index Ci), ordered sites along a gradient of management priorities that balances species-focused and habitat-focused conservation actions. Areas with the highest conservation priority were located in semi-deciduous forest fragments, followed by lowland forests. Many of these fragments, which are often embedded within large private landholdings including biofuel and citrus or coffee crops, cattle ranches and pulpwood plantations, could be used not only to comply with environmental legislation, but also enhance the prospects for biodiversity conservation, and reduce edge effects and hunting.  相似文献   

19.
For most carnivore populations, territoriality is the regulating social system ultimately determined by food abundance and/or strife. However, in some food-based territorial felid species such as the jaguar (Panthera onca), the influence of food availability on territoriality remains unclear and may be lessened because of a tendency for individuals to occur at high densities across the landscape. We examined spatial organization and use of food in a population of jaguars in the southern region of the Pantanal, Brazil (2003-04). We predicted that if territoriality plays an important role in determining jaguar population dynamics, exclusive use of territories should be observed and thereby influence prey selection patterns. We determined that home range sizes were comparable between sexes and overlapped little at the core area level. Line transect surveys revealed that large mammals comprised the bulk of available wild prey for jaguars, and scat analysis indicated that jaguars relied mostly on large mammalian prey. The most common wild species killed by jaguars were capybara (Hydrochaeris hydrochaeris) and caiman (Caiman yacare). We estimated that the wild prey base was adequate to support the jaguar population. Larger wild prey species were considerably more likely to die from predation than from other causes, and predation was more likely to occur in jaguar core areas than in areas of home range overlap. Modest cattle depredation rates had little demographic importance to the local jaguar population. We conclude that spacing patterns in the local jaguar population were likely based on exclusion through territoriality rather than food limitation.  相似文献   

20.
Bushmeat hunting is one of the primary threats to many large-bodied vertebrate species in African forests. However, species vary in their degree of vulnerability to hunting. We investigated the impact of hunting on monkey species in Cameroon’s Korup National Park (KNP) and examined how vulnerability to hunting varies among species. Data on primate abundance and hunting intensity were collected along 10 line transects, distributed across three survey areas in KNP. We assessed how the relative abundance of seven monkey species spatially varied between heavily and lightly hunted areas and evaluated temporal changes in the relative abundance and proportional representation of these species at a single hunted forest site and in bushmeat harvests. The putty-nosed and mona monkeys are most tolerant to heavy hunting pressure whereas the crowned monkey, drill, and red colobus are among the most vulnerable. At our heavily hunted survey site, the overall relative density of monkey groups increased through time but primate species richness declined. The proportional representation of Cercopithecus species, especially putty-nosed monkeys, increased through time, possibly due to competitive release. We also observed an increase in the proportional representation of the putty-nosed and mona monkeys and a reduced percent contribution of the red colobus and drill in hunter harvests. We conclude that hunting is driving some of Africa’s most threatened primate species (e.g., Preuss’s red colobus and the drill) to local extinction in KNP. We discuss intrinsic factors of species that might influence their degree of vulnerability and strategies to improve protection efforts in KNP.  相似文献   

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