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1.
We describe the food habits, niche overlap and prey preferences in a predator guild comprised of tigers Panthera tigris , leopards Panthera pardus and dholes Cuon alpinus in a mountainous region of central Bhutan. Scat analyses revealed that these predators consumed 11 different prey species including livestock and rodents, of which leopards consumed 11. The combined relative occurrence of the three species, sambar Cervus unicolor , muntjac Munticus muntjac and wild pig Sus scrofa , constituted 42.7, 33.7 and 71.1% of the tiger, leopard and dhole diets, respectively, while livestock comprised 44.5, 73.4 and 15.9% of the prey consumed, respectively. Regression equations from earlier feeding trials were used to estimate the relative biomass and the numbers of prey consumed. Results showed that sambar featured more frequently than did muntjac and wild pig in the diets of tiger, leopard and dhole and contributed more relative biomass than did muntjac and wild pig. Sambar, muntjac and wild pig together provided 36.9, 28 and 63.1% of the biomass consumed by tigers, leopards and dholes respectively. All else being equal, there was evidence that all three predators ate livestock less than might have been expected on the basis of the abundance and high biomass of this prey category in the area. There was a high dietary niche overlap between the predators (Pianka's overlap index of 0.58–0.92), with a greater overlap between the two felid species than between the felids and the canid. This study provides evidence of a substantial diet overlap among the three sympatric carnivores, and thus highlights the potential for high intra-guild competition among them, especially given the relatively low density of prey.  相似文献   

2.
Intraguild interactions among carnivores have long held the fascination of ecologists. Ranging from competition to facilitation and coexistence, these interactions and their complex interplay influence everything from species persistence to ecosystem functioning. Yet, the patterns and pathways of such interactions are far from understood in tropical forest systems, particularly across countries in the Global South. Here, we examined the determinants and consequences of competitive interactions between dholes Cuon alpinus and the two large felids (leopards Panthera pardus and tigers Panthera tigris) with which they most commonly co-occur across Asia. Using a combination of traditional and novel data sources (N = 118), we integrate information from spatial, temporal, and dietary niche dimensions. These three species have faced catastrophic declines in their extent of co-occurrence over the past century; most of their source populations are now confined to Protected Areas. Analysis of dyadic interactions between species pairs showed a clear social hierarchy. Tigers were dominant over dholes, although pack strength in dholes helped ameliorate some of these effects; leopards were subordinate to dholes. Population-level spatio-temporal interactions assessed at 25 locations across Asia did not show a clear pattern of overlap or avoidance between species pairs. Diet-profile assessments indicated that wild ungulate biomass consumption by tigers was highest, while leopards consumed more primate and livestock prey as compared to their co-predators. In terms of prey offtake (ratio of wild prey biomass consumed to biomass available), the three species together harvested 0.4–30.2% of available prey, with the highest offtake recorded from the location where the carnivores reach very high densities. When re-examined in the context of prey availability and offtake, locations with low wild prey availability showed spatial avoidance and temporal overlap among the carnivore pairs, and locations with high wild prey availability showed spatial overlap and temporal segregation. Based on these observations, we make predictions for 40 Protected Areas in India where temporally synchronous estimates of predator and prey densities are available. We expect that low prey availability will lead to higher competition, and in extreme cases, to the complete exclusion of one or more species. In Protected Areas with high prey availability, we expect intraguild coexistence and conspecific competition among carnivores, with spill-over to forest-edge habitats and subsequent prey-switching to livestock. We stress that dhole–leopard–tiger co-occurrence across their range is facilitated through an intricate yet fragile balance between prey availability, and intraguild and conspecific competition. Data gaps and limitations notwithstanding, our study shows how insights from fundamental ecology can be of immense utility for applied aspects like large predator conservation and management of human–carnivore interactions. Our findings also highlight potential avenues for future research on tropical carnivores that can broaden current understanding of intraguild competition in forest systems of Asia and beyond.  相似文献   

3.
Prey selection and the feeding habits of tiger Panthera tigris, leopard Panthera pardus and Asiatic wild dog Cuon alpinus were investigated from June 2009 to December 2011 in Pakke Tiger Reserve, Arunachal Pradesh. A total of 422 scats were analyzed of which, 109 scats were of tigers, 150 were of leopard and 163 scats were of dholes. Multinomial Likelihood ratio test was used to estimate the prey selectivity of predators and Ivlev index, Pianka index were used to estimate prey preference and overlap respectively. Biomass consumption for three sympatric predators varied from 254.3 kg for dholes to 599.1 kg for tigers. Sambar, barking deer, wild pig were preyed more than their availability by all the predators. Ivlev index shows barking deer and sambar were preferred more than available prey for tiger where as leopard preferred sambar more than available and avoided barking deer. Dhole preferred more than available wild pig and barking deer. There was a high overlap between tiger–leopard (85.3%) and tiger–dhole (77.5%). To the best of our understanding, this study provides the first reliable information on prey selection and food habits of sympatric large carnivores in a protected area of Eastern Himalayan tropical rainforest.  相似文献   

4.
Here, I report on how forest area in Southeast Asia has changed for different types of forest and across different countries between the periods of 1990–2000 and 2000–2005. The loss of old growth forests has accelerated in Indonesia, Cambodia and Vietnam but have ceased in Thailand, Malaysia, Laos and the Philippines. Secondary forests continue to be lost in Malaysia, Cambodia, Laos, Myanmar, Indonesia, Thailand and the Philippines. Plantation forests have increased in area by 25.0% from 1990 to 2005 but still comprise only 6.2% of the total forest area in Southeast Asia. Overall, the loss of native forests (old growth and secondary forests) has slowed down in Thailand, the Philippines and Brunei but has worsened in Laos, Myanmar, Indonesia, Malaysia and Cambodia.  相似文献   

5.
Prey preferences of large carnivores (tiger (Panthera tigris), leopard (Panthera pardus) and dhole (Cuon alpinus)) in the tropical forest of Anamalai Tiger Reserve (ATR) were evaluated. This was the first study in ATR to estimate the density of prey and the food habits of these large carnivores. The 958-km2 intensive study area was found to have a high mammalian prey density (72.1 animals per square kilometre) with wild boar (20.61 animals per square kilometre) and chital (20.54 animals per square kilometre) being the most common species, followed by nilgiri tahr (13.6 animals per square kilometre). When the density figures were multiplied by the average weight of each prey species, a high biomass density of 14,204 kg km−2 was obtained for the intensive study area. Scat analysis and incidental kill observation were used to determine the dietary composition of these predators. During the study from the period of March 2001 to April 2004, 1,145 tiger scats, 595 leopard scats and 2,074 dhole scats were collected and analysed. Kill data were based on direct observation of 66 tiger kills and 39 leopard kills. Sambar, with a density of 6.54 kg km−2 was the preferred prey for these carnivores. Sambar constitutes 35% of the overall diet of tiger, whereas it constitutes 17% and 25% in leopard and dhole diets, respectively. Chital was utilized less than sambar in the range of about 7%, 11% and 15% by tiger, leopard and dhole, respectively. Predator diet was estimated more accurately by scat analysis, which reveals 30% of smaller prey species in leopard’s diet, which was not observed by kill data. This study reveals that ATR harbours high prey density, and these large carnivores seem mostly dependent on the wild prey rather than on domestic livestock as in some other areas in the subcontinent. These factors make ATR a potential area for long-term conservation of these endangered carnivores.  相似文献   

6.
A questionnaire survey in 48 villages covering over 10,000 km2 in Arunachal Pradesh, India, was conducted to quantify the livestock depredation and resultant killing of dholes in retaliation. Depredation was reported to be caused highest by dhole (Cuon alpinus) in comparison to tiger (Panthera tigris) and leopard (Panthera pardus). Respondents claimed major losses (7.90 %) of socio-culturally valued livestock, i.e., mithun (Bos frontalis), to depredation. Scat analysis revealed livestock constituted only 10 % of the diet of dhole, tiger and leopard. Mithun depredation by dhole was correlated with hunting (r?=?0.54, P?r?=?0.54, P?dhole that correspond to their direct killing in retaliation may lead to unrecoverable losses in its population. This study highlights the significance of the region in securing the long-term survival of large carnivores, especially dholes, in this region.  相似文献   

7.
Dry deciduous dipterocarp forests (DDF) cover about 15%–20% of Southeast Asia and are the most threatened forest type in the region. The jungle cat (Felis chaus) is a DDF specialist that occurs only in small isolated populations in Southeast Asia. Despite being one of the rarest felids in the region, almost nothing is known about its ecology. We investigated the ecology of jungle cats and their resource partitioning with the more common leopard cats (Prionailurus bengalensis) in a DDF‐dominated landscape in Srepok Wildlife Sanctuary, Cambodia. We used camera‐trap data collected from 2009 to 2019 and DNA‐confirmed scats to determine the temporal, dietary and spatial overlap between jungle cats and leopard cats. The diet of jungle cats was relatively diverse and consisted of murids (56% biomass consumed), sciurids (15%), hares (Lepus peguensis; 12%), birds (8%), and reptiles (8%), whereas leopard cats had a narrower niche breadth and a diet dominated by smaller prey, primarily murids (73%). Nonetheless, dietary overlap was high because both felid species consumed predominantly small rodents. Both species were primarily nocturnal and had high temporal overlap. Two‐species occupancy modelling suggested jungle cats were restricted to DDF and had low occupancy, whereas leopard cats had higher occupancy and were habitat generalists. Our study confirmed that jungle cats are DDF specialists that likely persist in low numbers due to the harsh conditions of the dry season in this habitat, including annual fires and substantial decreases in small vertebrate prey. The lower occupancy and more diverse diet of jungle cats, together with the broader habitat use of leopard cats, likely facilitated the coexistence of these species. The low occupancy of jungle cats in DDF suggests that protection of large areas of DDF will be required for the long‐term conservation of this rare felid in Southeast Asia.  相似文献   

8.
We conducted a field study of diets of three sympatric large carnivores, the tiger Panthera tigris , the leopard Panthera pardus and the dhole Cuon alpinus in Bandipur Tiger Reserve, India, based on analyses of 381, 111 and 181 scats, respectively. The frequency of occurrence of prey items in scats was converted to relative biomass and number of prey consumed using regression equations based on earlier feeding trials. The results showed that although these predators kill ∼11–15 species of vertebrate prey, relatively abundant ungulate species provide 88–97% of biomass consumed by them. Although the dietary niche overlap among the three species was high (Pianka's index of 0.75–0.93), some specialized predation was observed. The largest ungulates, gaur Bos gaurus and sambar Cervus unicolor , provided 73% of biomass consumed by tigers, whereas medium-sized chital Axis axis and wild pig Sus scrofa formed 65 and 83% of the biomass intake of leopards and dholes, respectively. In terms of the relative numbers of prey animals killed by the three predators, chital, which is the most abundant prey species, dominated their diets (tiger=33%, leopard=39% and dhole=73%). The results of the study, in conjunction with earlier work, support the prediction that abundance of ungulate prey species, as well as their availability in different size classes, are both critical factors that facilitate sympatry among the three predators.  相似文献   

9.
In multipredator systems, group sizes of social carnivores are shaped by the asymmetric intraguild interactions. Subordinate social carnivores experience low recruitment rates as an outcome of predation pressure. In South and Southeast Asia, the Tiger (Panthera tigris), Dhole (Cuon alpinus), and Leopard (Panthera pardus) form a widely distributed sympatric guild of large carnivores, wherein tigers are the apex predators followed by dhole and leopard. In this study, we attempted to understand the variation in pack size of a social carnivore, the dhole, at two neighboring sites in the Central Indian landscape. We further evaluated local‐scale patterns of variation in pack size at a larger scale by doing a distribution‐wide assessment across the dhole ranging countries. At the local scale, we found an inverse relationship between the density of tiger and pack size of dhole while accounting for variability in resources and habitat heterogeneity. Larger dhole packs (16.8 ± 3.1) were observed at the site where the tiger density was low (0.46/100 km2), whereas a smaller pack size (6.4 ± 1.3) was observed in the site with high tiger density (5.36/100 km2). Our results for the distribution‐wide assessment were concordant with local‐scale results, showing a negative association of pack size with the tiger densities (effect size −0.77) and a positive association with the prey abundance (effect size 0.64). The study advances our understanding to answer the age‐old question of “what drives the pack size of social predators in a multipredator system?” This study also highlights the importance of understanding demographic responses of subordinate predator for varying competitor densities, often helpful in making informed decisions for conservation and management strategies such as population recovery and translocation of species.  相似文献   

10.
Studying large mammal species in tropical forests is a conservation challenge with species’ behavior and ecology often increasing the probability of non‐detection during surveys. Consequently, knowledge of the distribution, status, and natural history of many large mammal species in Southeast Asia is limited. I developed occupancy models from camera‐trapping data, thereby accounting for imperfect detection at sampling sites, to clarify the status and habitat requirements of four globally threatened or near threatened large mammals (banteng Bos javanicus, gaur Bos gaurus, dhole Cuon alpinus, and leopard Panthera pardus) in Mondulkiri Protected Forest, eastern Cambodia. Camera traps were operational for >3500 trap nights with 202 photographic encounters of the four study species. Model averaged occupancy estimates were between 5 percent (leopard) and 140 percent (gaur) higher than naive estimates (i.e., proportion of camera‐trap sites species recorded from) thus highlighting the importance of accounting for detectability during conservation surveys. I recommend the use of an occupancy framework when using camera‐trap data to study the status, ecology, and habitat preferences of poorly known and elusive species. The results highlight the importance of mixed deciduous and semi‐evergreen forest for wild cattle in eastern Cambodia and I emphasize that these habitats must be considered in conservation planning across the Lower Mekong Dry Forest Ecoregion.  相似文献   

11.
The population of the Asiatic wild dog or dhole (Cuon alpinus) in the wild has been estimated to be less than 2500 mature individuals. This has led to the IUCN assessing the Asiatic wild dog as Endangered. The killing of Asiatic wild dogs in retaliation for livestock depredation is one of the major threat for the species across its geographic range. Understanding the prey preference of endangered large carnivores is imperative for making informed conservation decisions and devising management strategies. We studied the prey preference of the Asiatic wild dog by reviewing studies that have been conducted on the diet and prey abundance of the species across its distributional range. Nine available studies conducted in eight protected areas of three countries, in which 5265 scats were studied, were reviewed. Across studies, we tested whether prey consumption was based on prey availability or prey body mass. The value of Jacobs’ index was determined for each prey species and tested against the proportion of available prey and body mass. Sambar (Rusa unicolor) and chital (Axis axis) were found to be significantly preferred by the Asiatic wild dog, and the preferred prey body mass range was between 40 and 60 kg. The prey preference of the Asiatic wild dog was mainly influenced by the availability of prey.  相似文献   

12.
  1. Large carnivores face high extinction risks, often exacerbated by the absence of adequate information on their ecological requirements, and the high economic and socio-political commitments that their conservation warrants. Country-scale conservation plans can serve as effective frameworks to prioritise areas, actions, and conservation investments.
  2. We explore conservation tenets of retention, recovery, and restoration for the Endangered dhole Cuon alpinus in India – a global stronghold for the species. Specifically, we: 1) examine the current status of dholes in India’s states using a recent distribution assessment; 2) identify areas for directing management interventions – zones to be targeted for population recovery and for habitat recovery; 3) identify potential areas for range expansion; 4) use eco-socio-political criteria to determine state-wise conservation priority scores and likelihood of conservation action; and 5) conduct an exhaustive review of all published literature on dholes.
  3. Dholes occupy ~49% of potential habitats in 685 of mainland India’s 2342 sub-districts. We identified 143 sub-districts with potential for dhole population recovery, 145 for habitat recovery, and 404 for range expansion. Of the 34 mainland states/union territories, 17 were identified as high priority for dhole conservation. Of these, nine are adequately equipped to implement management actions to conserve dholes, while eight need to improve capacity towards increasing likelihood of conservation success.
  4. Literature on dholes (from 1874 to 2019; n=237) was dominated by natural history notes, followed by distribution records and studies of population ecology. A majority of the reviewed studies were from India (55% of 215 country-specific papers). The number of studies showed an exponential increase over time: 43% were published in the last decade.
  5. Our review of published literature revealed significant knowledge gaps in terms of quantitative ecological assessments across all dhole range-countries. Given this context, our results provide a comprehensive, multi-dimensional, and administratively feasible road map for dhole conservation in India, with potential applicability in other dhole range-countries and also for other threatened species.
  相似文献   

13.
Two dhole ( Cuon alpinus ) packs were monitored in Mudumalai Sanctuary, southern India, during 1989-93 to look at population dynamics, movement pattern, and foraging strategy and their inter-relationship with the maintenance of social groups. Pack size fluctuated substantially (4–18 and 4–25 in the two packs) owing to dispersal and demographic factors such as females not breeding in a given year. Both packs killed a much higher proportion of chital ( Axis axis ) and sambar ( Cervus unicolor ) fawns (2 and 54.2km2 for the two packs) was not correlated with pack size. Pack movement from one resource patch (consisting of resting sites and aggregations of prey species) to another was not random or based on factors such as inter-patch distance or relative prey densities. There was no difference in mean residence time of the pack across the four resource patches; the pack moved across these in a sequential manner in one direction. We conclude that dholes live in groups not because of any advantages accruing from enhanced group sizes through increased per capita yield of food, but as a consequence of the dispersion of resources.  相似文献   

14.
Very little is known about prey selection by the Indian tiger Panthera tigris tigris in tropical dry deciduous forests or in wild herbivore-depleted habitats with high livestock pressures. We undertook a short-term study in a large south Indian tiger reserve and examined two intensive study areas (SA's) from October 1998 – June 1999. In each area, herbivore sightings were recorded, scats were collected, and wild prey and livestock kills documented. Chital, wild boar and sambar were the most abundant among the wild herbivores in the study area. Scat analysis revealed wild boar (Sus scrofa) being the most common prey followed by chital (Axis axis) and sambar (Rusa unicolor). Livestock comprised less than 7% of diet intake. Here, the tigers consumed a lower mean prey mass (56.3 kg) than in other reserves. Our study suggests that in tropical dry deciduous forests with low natural prey density, smaller prey species, and high livestock biomass, tigers preferentially kill smaller prey and generally avoid livestock predation.  相似文献   

15.
Dholes (Cuon alpinus Pallas, 1811) are carnivorous mammals classified as endangered according to the IUCN Red List. The northern boundary of the dhole range lies in Russia, but its current status there and in post-Soviet states is classified as “regionally extinct.” Moreover, most publications on dhole distribution in the former Soviet Union are only available in Russian. In this review, I summarize Russian-language sources of dhole distribution in the former USSR and modern Russia. I have created a database of all evidence regarding the capture and killing of dholes, as well as information about encounters with individuals/packs or their traces. Based on these data, I estimated the probability of extinction for the Tian Shan and Ussuri subspecies of dholes (C. alpinus hesperius and C. alpinus alpinus, respectively) using an approach based on a Bayesian model, Optimal Linear Estimation, and Sighting Trend Index. My review verifies that dholes were already extremely rare animals in the USSR in the first half of the twentieth century. The most recent proved report of dhole presence in Russia dates back to 1978, while the most recent data, for which there is no documentary evidence, was collected in 2009. Within the borders of the former USSR, the Tian Shan subspecies of dholes is probably already extinct (the probability that the subspecies is extant is 0.02; the null hypothesis that extinction has not occurred can be rejected with p = 0.057). The Ussuri subspecies possibly still exists in the Eastern Sayan Mountains and in the mountains of the Transbaikalia (p = 0.182, the probability that the subspecies is extant is 0.50).  相似文献   

16.
Chen  Xin  Ye  Mei  Wang  Yu  Zhang  Chiyu  Zheng  Yong-Tang 《中国病毒学》2020,35(5):538-547
Virologica Sinica - Laos is the only landlocked country in Southeast Asia and borders Thailand, Myanmar and Cambodia, the three countries in this region that have been hardest hit by human...  相似文献   

17.
No published information exists on the chemical immobilization of free-ranging dholes (Cuon alpinus), binturongs (Arctictis binturong), or yellow-throated martens (Martes flavigula). We chemically immobilized these species in Thailand using a mixture of ketamine hydrochloride with xylazine hydrochloride (KH–XH) and tiletamine hydrochloride with zolazepam hydrochloride (TH–ZH). Mean (±SD) dose of KH–XH was 18.1±5.3 and 0.9±0.1 mg/kg for dholes (n=2), 19.7±4.1 and 1.3±0.4 mg/kg for binturongs (n=8), and 28.7±3.3 and 1.1±0.1 mg/kg for yellow-throated martens (n=5), respectively. Mean dose of TH–ZH was 4.1±0.1 mg/kg for dhole (n=2). Induction time, duration of anesthesia, and recovery time were satisfactory for standard field research procedures including radio-collaring, although the effects on yellow-throated martens and binturongs were more variable. Respiration and muscle rigidity were monitored during sedation with no observed adverse physiological effects. Individuals were released after full recovery and monitored via radio telemetry for 4–23 months with no observed detrimental effects due to chemical immobilization. We conclude that KH–XH and TH–ZH are safe and effective immobilization agents for these carnivores; however, we suggest testing different KH–XH ratios and dosages, and other immobilizing agents for these species.  相似文献   

18.
Stable isotope analysis (SIA) of wolf (Canis lupus) tissues can be used to estimate diet and intra-population diet variability when potential prey have distinct δ13C and δ15N values. We tested this technique using guard hairs collected from 44 wolves in 12 northwestern Montana packs, summer 2009. We used hierarchical Bayesian stable isotope mixing models to determine diet and scales of diet variation from δ13C and δ15N of wolves and potential prey, white-tailed deer (Odocoileus virginianus), mule deer (Odocoileus hemionus), elk (Cervus canadensis), moose (Alces alces), snowshoe hare (Lepus americanus), and other prey. As a check on SIA results, we conducted a separate diet analysis with temporally matched scats (i.e., collected in summer 2008) from 4 of the same packs. Wolves were centered on the ungulate prey in the isotope mixing space. Both methods revealed differences among pack diets and that wolves may consume moose in greater proportions than predicted by available biomass. Stable isotope analysis, and scat results were not entirely concordant; assumptions related to tissues of use in SIA, hair growth period in wolves, and scat sampling may have contributed to a mismatch between methods. Incorrect fractionation values, insufficient separation of prey in the isotope mixing space, choice of prior information in the Bayesian mixing models, and unexplained factors may have distorted diet estimates. However, the consistently high proportion of moose in pack diets suggests that increased population monitoring would benefit management of moose and wolves. Our results also support suggestions of other researchers that species-specific fractionation values should be used whenever possible, and that SIA may sometimes only provide indices of use for general groups of prey (e.g., large ungulates). © 2012 The Wildlife Society.  相似文献   

19.
Capsicum Use in Cambodia: The Continental Region of Southeast Asia Is Not Related to the Dispersal Route of C. frutescens in the Ryukyu Islands. The local nomenclature and use of Capsicum by Khmer and other ethnic groups in Cambodia and the distribution of the diagnostic ShDH-B isozyme pattern of C. frutescens were studied. People in Cambodia use Capsicum in various ways, not only as a condiment but also as a vegetable, a medicine, and a colorant, and in popular beliefs, agricultural rituals, taboos, and rice malt. The findings showed that the ShDH-B phenotype may not have occurred as a mutation in Asia but in the Americas and then was introduced to Asia. Also, the ShDH-B phenotype is distributed in the insular regions of Southeast and East Asia and Oceania, but seems not to be distributed in the continental region of Southeast Asia. One possible hypothesis is that C. frutescens possessing the ShDH-B phenotype was introduced directly from the Americas via Oceania to the Philippines, and it thereafter dispersed into the insular regions.  相似文献   

20.
The Asiatic wild dog or dhole was once very widely distributed across Asia but now has a very fragmented range. In this first genetic study of this little-known species, we obtained information on genetic diversity, phylogeography, and social structure using both mitochondrial control region sequencing and microsatellite genotyping of noninvasive faecal samples from wild populations, as well as from museum and captive samples. A pattern largely consistent with isolation by distance across the Asian mainland was observed, with no clear subspecies distinctions. However, two major phylogeographical groupings were found across the mainland, one extending from South, Central, and North India (south of the Ganges) into Myanmar, and the other extending from India north of the Ganges into northeastern India, Myanmar, Thailand and the Malaysian Peninsula. We propose a scenario involving glaciation events that could explain this pattern. The origin of the dhole populations in Sumatra and Java is enigmatic and requires further study. Very low levels of genetic diversity were observed among wild dholes from Baluran National Park in Java, Indonesia, but in contrast, high levels were observed in Mudumalai Wildlife Sanctuary in South India.  相似文献   

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