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Srivathsa A, Ramachandran V, Saravanan P, Sureshbabu A, Ganguly D, Ramakrishnan U. Topcats and underdogs: intraguild interactions among three apex carnivores across Asia's forestscapes. Biol Rev Camb Philos Soc 2023; 98:2114-2135. [PMID: 37449566 DOI: 10.1111/brv.12998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 06/26/2023] [Accepted: 07/04/2023] [Indexed: 07/18/2023]
Abstract
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.
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Affiliation(s)
- Arjun Srivathsa
- National Centre for Biological Sciences, TIFR, GKVK Campus, Bellary Road, Bengaluru, 560065, India
- Wildlife Conservation Society-India, 551, 7th Main Road, 2nd Stage Rajiv Gandhi Nagar, Kodigehalli, Bengaluru, 560097, India
| | - Vivek Ramachandran
- National Centre for Biological Sciences, TIFR, GKVK Campus, Bellary Road, Bengaluru, 560065, India
- Wildlife Biology and Conservation Program, National Centre for Biological Sciences, TIFR, GKVK Campus, Bellary Road, Bengaluru, 560065, India
| | - Pooja Saravanan
- National Centre for Biological Sciences, TIFR, GKVK Campus, Bellary Road, Bengaluru, 560065, India
| | - Abhijith Sureshbabu
- National Centre for Biological Sciences, TIFR, GKVK Campus, Bellary Road, Bengaluru, 560065, India
| | - Divyajyoti Ganguly
- National Centre for Biological Sciences, TIFR, GKVK Campus, Bellary Road, Bengaluru, 560065, India
- Wildlife Biology and Conservation Program, National Centre for Biological Sciences, TIFR, GKVK Campus, Bellary Road, Bengaluru, 560065, India
| | - Uma Ramakrishnan
- National Centre for Biological Sciences, TIFR, GKVK Campus, Bellary Road, Bengaluru, 560065, India
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Deka JR, Ali SZ, Ahamad M, Borah P, Gopi GV, Badola R, Sharma R, Hussain SA. Can Bengal Tiger ( Panthera tigris tigris) endure the future climate and land use change scenario in the East Himalayan Region? Perspective from a multiple model framework. Ecol Evol 2023; 13:e10340. [PMID: 37554398 PMCID: PMC10404654 DOI: 10.1002/ece3.10340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 07/07/2023] [Accepted: 07/10/2023] [Indexed: 08/10/2023] Open
Abstract
Large mammals are susceptible to land use and climate change, unless they are safeguarded within large, protected areas. It is crucial to comprehend the effects of these changes on mammals to develop a conservation plan. We identified ecological hotspots that can sustain an ecosystem for the endangered Bengal tiger (Panthera tigris tigris), an umbrella species. We developed three distinct ensemble species distribution models (SDMs) for the Bengal tiger in the Indian East Himalayan Region (IEHR). The first model served as the baseline and considered habitat type, climate, land cover, and anthropogenic threats. The second model focused on climate, land use, and anthropogenic threats, the third model focused on climate variables. We projected the second and third models onto two future climate scenarios: RCP 4.5 and RCP 8.5. We evaluated the threats possess to protected areas within eco-sensitive zone based on the potential tiger habitat. Finally, we compared the potential habitat with the IUCN tiger range. Our study revealed that the Brahmaputra valley will serve as the primary habitat for tigers in the future. However, considering the projected severe climate scenarios, it is anticipated that tigers will undergo a range shift towards the north and east, especially in high-altitude regions. Very high conservation priority areas, which make up 3.4% of the total area, are predominantly located in the riverine corridor of Assam. High conservation priority areas, which make up 5.5% of total area are located in Assam and Arunachal Pradesh. It is important to note that conservation priority areas outside of protected areas pose a greater threat to tigers. We recommend reassessing the IUCN Red List's assigned range map for tigers in the IEHR, as it is over-predicted. Our study has led us to conclude both land use and climate change possess threats to the future habitat of tigers. The outcomes of our study will provide crucial information on identifying habitat hotspots and facilitate appropriate conservation planning efforts.
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Affiliation(s)
| | | | | | | | | | - Ruchi Badola
- Wildlife Institute of IndiaDehradunUttarakhandIndia
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Chatterjee M, Chatterjee N, Chandel P, Bhattacharya T, Kaul R. Predicting negative human-tiger (Panthera tigris) interactions in mosaic landscapes around Dudhwa and Pilibhit tiger reserves in India. FRONTIERS IN CONSERVATION SCIENCE 2022. [DOI: 10.3389/fcosc.2022.999195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Negative interactions between humans and large carnivores like tigers (Panthera tigris) and leopards (Panthera pardus) are of concern for the conservation of these carnivores, as well as for the health and wellbeing of people who experience such interactions routinely. Such interactions not only lead to human deaths, injuries and loss of domestic animals, but also can result in retaliatory persecution of carnivores and cause their population declines. The Dudhwa-Pilibhit landscape in the northern Indian state of Uttar Pradesh is popularly regarded to be the second most affected hotspot of human-tiger conflicts in the country. Yet, very little information is published on human-tiger conflicts in this landscape. In this study, we recorded 7.4 ± 5.8 (range: 1-20) negative interactions per year between people and tigers that led directly to human deaths and injuries. Although there appeared to be peaks in negative interactions in more recent years, these were found to be statistically non-significant. The peaks in the numbers of cases in 2009-10 and 2016-17 can be attributed to higher numbers of human casualties cause by individual ‘problem’ tigers, and not due to an increase in the number of tigers engaging in conflicts. We used binomial generalized linear modelling to model the risk to humans from being attacked by tigers depending on landscape characteristics. This approach demonstrated that the mosaics of forests and human settlements, especially the presence of agriculture, forest patches and waterbodies, were the predominant factors at play. Notably, higher risks were not mediated by the presence of larger cattle population. Proximity of villages to forests or natural vegetation patches was the most significantly contributing factor identified by the model output. This suggested that despite the prevalent perception of attacks on humans occurring in human-dominated areas of this landscape, areas with forests or other natural vegetation entailed higher risks. This was corroborated by field observations, with most attacks occurring within, or close to, forests or dense vegetation. Based on these findings, we recommend that restricting human movements and taking precautionary measures in high-risk areas can significantly reduce negative interactions with tigers in our study area.
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Karandikar H, Serota MW, Sherman WC, Green JR, Verta G, Kremen C, Middleton AD. Dietary patterns of a versatile large carnivore, the puma ( Puma concolor). Ecol Evol 2022; 12:e9002. [PMID: 35784054 PMCID: PMC9240727 DOI: 10.1002/ece3.9002] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 05/13/2022] [Accepted: 05/16/2022] [Indexed: 11/11/2022] Open
Abstract
Large carnivores play critical roles in terrestrial ecosystems but have suffered dramatic range contractions over the past two centuries. Developing an accurate understanding of large carnivore diets is an important first step towards an improved understanding of their ecological roles and addressing the conservation challenges faced by these species.The puma is one of seven large felid species in the world and the only one native to the non-tropical regions of the New World. We conducted a meta-analysis of puma diets across the species' range in the Americas and assessed the impact of varying environmental conditions, niche roles, and human activity on puma diets. Pumas displayed remarkable dietary flexibility, consuming at least 232 different prey species, including one Critically Endangered and five Endangered species.Our meta-analysis found clear patterns in puma diets with changing habitat and environmental conditions. Pumas consumed more larger-bodied prey species with increasing distance from the equator, but consumption of medium-sized species showed the opposite trend.Puma diets varied with their realized niche; however, contrary to our expectations, puma consumption of large species did not change with their trophic position, and pumas consumed more small prey and birds as apex predators. Consumption of domestic species was negatively correlated with consumption of medium-sized wild species, a finding which underscores the importance of maintaining intact native prey assemblages.The tremendous dietary flexibility displayed by pumas represents both an opportunity and a challenge for understanding the puma's role in ecosystems and for the species' management and conservation. Future studies should explore the linkages between availability and selection of primary and other wild prey, and consequent impacts on predation of domestic species, in order to guide conservation actions and reduce conflict between pumas and people.
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Affiliation(s)
- Harshad Karandikar
- Department of Environmental Science, Policy & ManagementMulford HallUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - Mitchell W. Serota
- Department of Environmental Science, Policy & ManagementMulford HallUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - Wilson C. Sherman
- Department of Environmental Science, Policy & ManagementMulford HallUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - Jennifer R. Green
- Department of Environmental Science, Policy & ManagementMulford HallUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - Guadalupe Verta
- Department of Environmental Science, Policy & ManagementMulford HallUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - Claire Kremen
- Department of Environmental Science, Policy & ManagementMulford HallUniversity of CaliforniaBerkeleyCaliforniaUSA
- Institute for Resources, Environment and SustainabilityUniversity of British ColumbiaVancouverBritish ColumbiaCanada
- Department of ZoologyBiodiversity Research CentreUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Arthur D. Middleton
- Department of Environmental Science, Policy & ManagementMulford HallUniversity of CaliforniaBerkeleyCaliforniaUSA
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Kannan P, Salaria S, Khan S, Mark T, Baberwal N, Bhatnagar A, Shethia Y, Thatte P, Chanchani P. Assessing Carnivore Occurrence and Community Attitudes Towards Wildlife in a Multi-Use Arid Landscape Corridor. FRONTIERS IN CONSERVATION SCIENCE 2022. [DOI: 10.3389/fcosc.2021.787431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Small population sizes, low densities, and large area requirements make large carnivores particularly sensitive to habitat degradation and land-use change. In fragmented landscapes, many protected areas cannot accommodate viable wildlife populations in themselves, which brings the surrounding human-dominated matrix that may extend wildlife habitats or serve as corridors into focus. Such areas are typically excluded from the conservation portfolio and are subject to rapid land -use change in many areas. This study investigates the occurrence of tigers, sloth bears, leopards and striped hyenas and assesses community use of natural resources and attitudes towards wildlife in a 3,384 km2 portion of semi-arid multiple-use landscape in Western India that also serves as an important wildlife corridor. This area abuts Ranthambore Tiger Reserve, a preeminent protected area in Western India. Sign surveys spanning 1,039.22 km of trails were conducted in 94, 36 km2 grids spanning agricultural land, forests and other land use types to collate information on wildlife occurrence and associated environmental and human factors. Analysis using occupancy models revealed that tiger and sloth bear occurrence probabilities (0.093 ± 0.05), and (0.13 ± 0.02) were considerably lower than those for leopards (0.72 ± 0.22) and striped hyenas (0.91 ± 0.08). Lack of sufficient cover and limited food availability renders these multiple-use habitats poorly suited for tigers and sloth bears, while leopards and hyenas are able to adapt better to multi-use areas. Concurrently, 66 villages were surveyed across the study landscape, where data on broad socio-economic attributes of communities and their attitudes towards wildlife were assessed through questionnaire surveys. More respondents expressed negative attitudes than positive attitudes which vary as a function of education levels, occupation and land holding sizes. Ongoing landscape transformation through mining, agricultural expansion, infrastructure development, and negative attitudes towards wildlife conservation among people living in the agricultural matrix threatens the long-term functionality of these corridors. Therefore, immediate measures are needed to develop and implement corridor conservation strategies and plans, with a focus on land use planning and human-wildlife conflict mitigation. In the absence of decisive and timely action, wildlife populations may increasingly get relegated to fragmented patches, jeopardising their persistence.
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Warrier R, Noon BR, Bailey LL. A Framework for Estimating Human-Wildlife Conflict Probabilities Conditional on Species Occupancy. FRONTIERS IN CONSERVATION SCIENCE 2021. [DOI: 10.3389/fcosc.2021.679028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Managing human-wildlife conflicts (HWCs) is an important conservation objective for the many terrestrial landscapes dominated by humans. Forecasting where future conflicts are likely to occur and assessing risks to lives and livelihoods posed by wildlife are central to informing HWC management strategies. Existing assessments of the spatial occurrence patterns of HWC are based on either understanding spatial patterns of past conflicts or patterns of species distribution. In the former case, the absence of conflicts at a site cannot be attributed to the absence of the species. In the latter case, the presence of a species may not be an accurate measure of the probability of conflict occurrence. We present a Bayesian hierarchical modeling framework that integrates conflict reporting data and species distribution data, thus allowing the estimation of the probability that conflicts with a species are reported from a site, conditional on the species being present. In doing so, our model corrects for both false-positive and false-negative conflict reporting errors. We provide study design recommendations using simulations that explore the performance of the model under a range of conflict reporting probabilities. We applied the model to data on wild boar (Sus scrofa) space use and conflicts collected from the Central Terai Landscape (CTL), an important tiger conservation landscape in India. We found that tolerance for wildlife was a predictor of the probability with which farmers report conflict with wild boars from sites not used by the species. We also discuss useful extensions of the model when conflict data are verified for potential false-positive errors and when landscapes are monitored over multiple seasons.
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Trends in Wildlife Connectivity Science from the Biodiverse and Human-Dominated South Asia. J Indian Inst Sci 2021. [DOI: 10.1007/s41745-021-00240-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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