13 research outputs found

    Identifying conservation priorities for an understudied species in decline: Golden cats (Catopuma temminckii) in mainland Tropical Asia

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    Abstract Identifying conservation priorities for an understudied species can be challenging, as the amount and type of data available to work with are often limited. Here, we demonstrate a flexible workflow for identifying priorities for such data-limited species, focusing on the little-studied Asian golden cat (Catopuma temminckii) in mainland Tropical Asia. Using recent occurrence records, we modeled the golden cat's expected area of occurrence and identified remaining habitat strongholds (i.e., large intact areas with moderate-to-high expected occurrence). We then classified these strongholds by recent camera-trap survey status (from a literature review) and near-future threat status (based on publicly available forest loss projections and Bayesian Belief Network derived estimates of hunting-induced extirpation risk) to identify conservation priorities. Finally, we projected the species' expected area of occurrence in the year 2000, approximately three generations prior to today, to define past declines and better evaluate the species' current conservation status. Lower levels of hunting-induced extirpation risk and higher levels of closed-canopy forest cover were the strongest predictors of recent camera-trap records. Our projections suggest a 68% decline in area with moderate-to-high expected occurrence between 2000 and 2020, with a further 18% decline predicted over the next 20 years. Past and near-future declines were primarily driven by cumulatively increasing levels of hunting-induced extirpation risk, suggesting assessments of conservation status based solely on declines in habitat may underestimate actual population declines. Of the 40 remaining habitat strongholds, 77.5% were seriously threatened by forest loss and hunting. Only 52% of threatened strongholds had at least one site surveyed, compared to 100% of low-to-moderate threat strongholds, thus highlighting an important knowledge gap concerning the species' current distribution and population status. Our results suggest the golden cat has experienced, and will likely continue to experience, considerable population declines and should be considered for up-listing to a threatened category (i.e., VU/EN) under criteria A2c of the IUCN Red List

    Pangolins in global camera trap data: Implications for ecological monitoring

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    Despite being heavily exploited, pangolins (Pholidota: Manidae) have been subject to limited research, resulting in a lack of reliable population estimates and standardised survey methods for the eight extant species. Camera trapping represents a unique opportunity for broad-scale collaborative species monitoring due to its largely non-discriminatory nature, which creates considerable volumes of data on a relatively wide range of species. This has the potential to shed light on the ecology of rare, cryptic and understudied taxa, with implications for conservation decision-making. We undertook a global analysis of available pangolin data from camera trapping studies across their range in Africa and Asia. Our aims were (1) to assess the utility of existing camera trapping efforts as a method for monitoring pangolin populations, and (2) to gain insights into the distribution and ecology of pangolins. We analysed data collated from 103 camera trap surveys undertaken across 22 countries that fell within the range of seven of the eight pangolin species, which yielded more than half a million trap nights and 888 pangolin encounters. We ran occupancy analyses on three species (Sunda pangolin Manis javanica, white-bellied pangolin Phataginus tricuspis and giant pangolin Smutsia gigantea). Detection probabilities varied with forest cover and levels of human influence for P. tricuspis, but were low (<0.05) for all species. Occupancy was associated with distance from rivers for M. javanica and S. gigantea, elevation for P. tricuspis and S. gigantea, forest cover for P. tricuspis and protected area status for M. javanica and P. tricuspis. We conclude that camera traps are suitable for the detection of pangolins and large-scale assessment of their distributions. However, the trapping effort required to monitor populations at any given study site using existing methods appears prohibitively high. This may change in the future should anticipated technological and methodological advances in camera trapping facilitate greater sampling efforts and/or higher probabilities of detection. In particular, targeted camera placement for pangolins is likely to make pangolin monitoring more feasible with moderate sampling efforts

    Pangolins in Global Camera Trap Data: Implications for Ecological Monitoring

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    Despite being heavily exploited, pangolins (Pholidota: Manidae) have been subject to limited research, resulting in a lack of reliable population estimates and standardised survey methods for the eight extant species. Camera trapping represents a unique opportunity for broad-scale collaborative species monitoring due to its largely non-discriminatory nature, which creates considerable volumes of data on a relatively wide range of species. This has the potential to shed light on the ecology of rare, cryptic and understudied taxa, with implications for conservation decision-making. We undertook a global analysis of available pangolin data from camera trapping studies across their range in Africa and Asia. Our aims were (1) to assess the utility of existing camera trapping efforts as a method for monitoring pangolin populations, and (2) to gain insights into the distribution and ecology of pangolins. We analysed data collated from 103 camera trap surveys undertaken across 22 countries that fell within the range of seven of the eight pangolin species, which yielded more than half a million trap nights and 888 pangolin encounters. We ran occupancy analyses on three species (Sunda pangolin Manis javanica, white-bellied pangolin Phataginus tricuspis and giant pangolin Smutsia gigantea). Detection probabilities varied with forest cover and levels of human influence for P. tricuspis, but were low (M. javanica and S. gigantea, elevation for P. tricuspis and S. gigantea, forest cover for P. tricuspis and protected area status for M. javanica and P. tricuspis. We conclude that camera traps are suitable for the detection of pangolins and large-scale assessment of their distributions. However, the trapping effort required to monitor populations at any given study site using existing methods appears prohibitively high. This may change in the future should anticipated technological and methodological advances in camera trapping facilitate greater sampling efforts and/or higher probabilities of detection. In particular, targeted camera placement for pangolins is likely to make pangolin monitoring more feasible with moderate sampling efforts

    Lower levels of human disturbance correspond with longer-term persistence of Endangered Green Peafowl Pavo muticus populations

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    Galliformes are one of the most threatened groups of birds in South-East Asia, with 27% of the species threatened with extinction. Long term population viability and extinction probability studies, at different levels of threat and management, are lacking due to weak life history data. This study aimed to define the long-term viability and extinction risk of two populations of the endangered Green Peafowl Pavo muticus, facing different threat and protection levels, using Bayesian Population Viability Analysis (BPVA), which requires less data than traditional methods. The results showed an increasing trend in the Green Peafowl population in HuaiKhaKhaeng Wildlife Sanctuary (western Thailand), with a high protection level and low disturbance and high probability of assuring persistence for the next 100 years. By contrast, the population in YokDon National Park (south-central Vietnam), with a high habitat disturbance level and significant hunting pressure, is predicted to decline and has a high probability (99%) of extinction by 2097. Also, the BPVA showed minimum viable population (MVP) estimates of 250 and 450 calling males for the HuaiKhaKhaeng and YokDon populations respectively, assuring high probabilities of long-term persistence if the minimum numbers of males are available. The population size of 219 calling males at YokDon during the 2013 survey is lower than the MVP threshold of 450 calling males, which suggests the species has a low probability of long-term persistence in the area. Despite limited life history and population data, BPVA predicted the future of this population under site-specific conditions, and the results could be used to promote better management and population restoratio

    Lower levels of human disturbance correspond with longer-term persistence of Endangered Green Peafowl Pavo muticus populations

    No full text
    Galliformes are one of the most threatened groups of birds in South-East Asia, with 27% of the species threatened with extinction. Long term population viability and extinction probability studies, at different levels of threat and management, are lacking due to weak life history data. This study aimed to define the long-term viability and extinction risk of two populations of the endangered Green Peafowl Pavo muticus, facing different threat and protection levels, using Bayesian Population Viability Analysis (BPVA), which requires less data than traditional methods. The results showed an increasing trend in the Green Peafowl population in HuaiKhaKhaeng Wildlife Sanctuary (western Thailand), with a high protection level and low disturbance and high probability of assuring persistence for the next 100 years. By contrast, the population in YokDon National Park (south-central Vietnam), with a high habitat disturbance level and significant hunting pressure, is predicted to decline and has a high probability (99%) of extinction by 2097. Also, the BPVA showed minimum viable population (MVP) estimates of 250 and 450 calling males for the HuaiKhaKhaeng and YokDon populations respectively, assuring high probabilities of long-term persistence if the minimum numbers of males are available. The population size of 219 calling males at YokDon during the 2013 survey is lower than the MVP threshold of 450 calling males, which suggests the species has a low probability of long-term persistence in the area. Despite limited life history and population data, BPVA predicted the future of this population under site-specific conditions, and the results could be used to promote better management and population restorationacceptedVersio

    Change in status of green peafowl Pavo muticus (Family Phasianidae) in Southcentral Vietnam: A comparison over 15 years

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    Biodiversity declines in Southeast Asia have led to predictions that many vertebrate species will become extinct within 50 years. Examples of quantified deterioration in species status remain scarce, however. The Southeast Asian geographical range of the Endangered Green peafowl is still contracting due to hunting pressure and habitat disturbance. In Vietnam, the main population lies in the southcentral region with a relatively high density reported in 1998. The aim of this study was to assess the species’ current status in Yok Don and Cat Tien National Parks, which are thought to contain the most important Vietnamese populations. We used line and point transects to investigate the density and analyze habitat selection and effects of human activity. The Yok Don population has decreased sharply during the past 15 years, while in Cat Tien, the estimated density was higher. Animals were most numerous close to water sources and lowest where cattle numbers were highest and ground vegetation cover absent. Here we document a significant negative population change in a previously widespread vertebrate species. Although comparisons of population data over long periods are rare, we demonstrate that taking advantage of opportunities to resurvey species can quantify population declines

    The threat of free-ranging domestic dog to native wildlife: implication for conservation in Southeast Asia

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    The global population of domestic dogs is estimated at 900 million, making them the world’s most abundant carnivore. Southeast Asia is considered extremely vulnerable to wildlife declines linked to free-ranging dogs, yet few studies report specific cases of dog-wildlife interactions in this region. To overcome this lack of data, the perceived risk to bird and mammal species from free-ranging domestic dogs was modelled using Bayesian networks considering the life history traits of each individual species. The spatial distribution of perceived risk across Southeast Asia was then modelled using a Bayesian network incorporating landscape and demographic characteristics. The number of species considered as high perceived risk in the region was over five times that previously reported. Overall, 11% of bird species and 10% of mammal species were classified as at high perceived risk from free-ranging domestic dogs and eight of these species were listed as Critically Endangered or Endangered by the IUCN Redlist. Furthermore, 50% of mainland Southeast Asia was predicted to be of high perceived risk from free-ranging domestic dogs with only 9% of the region considered as low perceived risk. When empirical data is lacking on IUCN Redlist assessments, incorporation of single threat models can provide missing information critical for accurate evaluation. It is recommended that species are re-evaluated considering domestic dogs as a threat and that this study be used as a template to assist in the development of species action plans and to define key areas where dog management needs to be considered. Management practices should be culturally appropriate and overall promote responsible pet ownership. Canis familiaris, dog-wildlife conflict, predation, Bayesian network, threat mapacceptedVersio

    Living with human encroachment: Status and distribution of Green Peafowl in northern stronghold of Thailand

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    Green Peafowl have declined significantly across much of their historical range mostly due to habitat loss and degradation following intensive agricultural expansion, logging and infrastructure development. In Thailand, two strongholds remain, in the west and the north. While the western stronghold has been extensively investigated and is well protected, the status of the species in the northern stronghold remain unknown. This stronghold is distributed over at least four contiguous protected areas surrounded by agricultural landscapes, where conflict with farmers has recently been reported. The aims of this work are to 1) investigate the species’ status in this northern stronghold, 2) define the species’ habitat use within and outside protected areas, and 3) to provide management suggestions for the species’ long-term survival. Our results showed a high probability of species occurrence (>0.5) in the stronghold within the four protected areas. Using Distance sampling over 54 transects, 2 km long, located in the interior, edge and agriculture landscape, we estimated a density of 15.82 calling males/km2 over the whole stronghold with densities ranging from 13.55 to 19.89 calling males/km2 in the four protected areas separately. A general linear models showed that species distribution was affected positively by dry dipterocarp forest, the main species’ habitat over its range, and negatively by human settlements. A higher number of the species was predicted within the protected areas than outside, highlighting the significance of the protected contiguous forest patches in the stronghold for the long-term conservation of the species combined with the supporting agro-ecotourism through the species existence in the surrounding agricultural landscapes. Beside protected areas management, cooperation by local communities has to be included in any conservation program to avert human-wildlife conflict

    Low-intensive agricultural landscapes could help to sustain Green Peafowl Pavo muticus inhabiting surrounding forest patches in Northern Thailand

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    Wildlife in Southeast Asia is greatly affected by agricultural expansion. While intensive farming causes biodiversity decline, low-intensive farming can support some adapted wildlife. In Thailand, the rapid transformation of forests to agricultural landscapes over three decades has resulted in large forest and biodiversity loss, with several Endangered species suffering from cropland expansion. Among these, the Green Peafowl, an Endangered Galliformes widely distributed across Southeast Asia, has shown the capacity to adapt well to low-intensive agriculture landscapes by using crops as food sources. Here we investigated in detail the Green Peafowl’s habitat use in an agricultural landscape surrounding a large forest patch composed of three protected areas in northern Thailand. Using line transect surveys and compositional analysis, we estimated the monthly Peafowl use of different crop types and different crop structures between January 2020 and January 2021. The Green Peafowl’s habitat use was significantly non-random. The order of habitat preference was timber plantations > orchards > cropland > fallow land. The species also preferred cropland within a 500 m buffer zone around the forest patch. The species preferred crops with a canopy structure (timber and orchards) that resembles their natural habitat. Our results confirm that low-intensive and diversified agricultural landscapes could help to sustain the Green Peafowl population. Importantly, we also show that closed canopy crops, such as large tree plantations like teak, rubber and orchards, can provide good alternatives for reforestation to reconnect forest fragments and isolated patches in highly degraded habitats as they allow the species to move further away from forest edges within the degraded landscape

    The spatial and temporal displacement of native species by domestic dogs

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    Domestic dogs have been predicted to be a high risk to 10 % of mammal and 11 % of bird species across mainland Southeast Asia. Within Thailand their population is estimated at over 12 million and 80 % live in rural areas where they adopt a free-ranging lifestyle. This lifestyle enables them to enter protected forests without restrictions. To access the spatial and temporal impacts domestic dogs have on local wildlife a two-year camera trap study was undertaken in a fragmented forest complex in Northern Thailand. Co-occurrence modelling was used to estimate the impacts of domestic dogs on a native predator (golden jackal) and prey (green peafowl) specie’s occurrence probability. Temporal segregation was accessed using activity pattern overlaps and compared to Huai Kha Khaeng, a more protected and unfragmented forest complex. Although the results from the co-occurrence models did not find any spatial segregation, it was found that temporal avoidance was occurring in the protected areas with domestic dogs and golden jackal having a clear temporal niche, this temporal separation was lessened in the unfragmented forest. Additionally, over 3x more humans were independently photographed than any other species and 2.5x more domestic dogs were independently photographed than golden jackal in the fragmented protected areas. Ultimately, working in partnership with the local community on approaches that will reduce domestic dogs presence in the forest is essential along with a stringent population management plan in order to lower the number of free-ranging dogs in the area
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