Population characteristics and habitat suitability of Asian elephants (Elephas maximus Linnaeus, 1758) in the Khao Yai National Park, Thailand

The aim of this study was to investigate the population and habitat of wild elephants in the Khao Yai National Park, to provide elephant population densities using the line transect method. Habitat suitability was also assessed based on the data obtained from the location of the species during monthly ranger patrol across the park area, with the rate of dung decay used for population calculation. The population structure and age class were studied by direct observation to estimate the population trend. On the basis of 116 systematic transect lines that were 2 km in length and separated by 500-m intervals, a total of 1,209 elephant dung piles were found in more than 213.20 km. The analysis of the combined data showed that the dung density was 531.49 dung piles/km 2, with a decay rate of 0.0039 dung piles/day based on 56 dung piles checked every 7 days. The annual data showed that the population density was 0.15 individuals/km 2. The population structure comprising  calf:juvenile:subadult:adult was 1: 1.09:1.14:2.10; the sex ratio of adult male to adult female elephants was 1:1.10; and the ratio of reproductive ability among adult females, juveniles, and calves was 1.00:0.99:0.90. The combined data also showed that the main environmental factor affecting the presence of the animals was salt lick sites. The pooled data analysis found that the habitat most suitable for the elephants covered an area of 220.59 km 2. The habitat suitability, based on the dry season appearance data, covered an area of 258.64 km 2, whereas during the wet season, it covered an area of 517.45 km 2. As the most suitable habitat for elephants appears around the park boundary, habitat improvements for wild elephants should address the central areas of the national park. A greater emphasis should be placed on creating salt licks, being far from human activity sites

Using global remote camera data of a solitary species complex to evaluate the drivers of group formation

We would like to thank Megan Whatton, Belden Giman, Hongliang Bu, Dajun Wang, Fang Wang, Roland Kays, Jillian Kilborn, and New Hampshire Fish and Game for their roles in contributing data that was used in this analysis. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the US Government.Peer reviewe

CamTrapAsia: a dataset of tropical forest vertebrate communities from 239 camera trapping studies

Information on tropical Asian vertebrates has traditionally been sparse, particularly when it comes to cryptic species inhabiting the dense forests of the region. Vertebrate populations are declining globally due to land-use change and hunting, the latter frequently referred as “defaunation.” This is especially true in tropical Asia where there is extensive land-use change and high human densities. Robust monitoring requires that large volumes of vertebrate population data be made available for use by the scientific and applied communities. Camera traps have emerged as an effective, non-invasive, widespread, and common approach to surveying vertebrates in their natural habitats. However, camera-derived datasets remain scattered across a wide array of sources, including published scientific literature, gray literature, and unpublished works, making it challenging for researchers to harness the full potential of cameras for ecology, conservation, and management. In response, we collated and standardized observations from 239 camera trap studies conducted in tropical Asia. There were 278,260 independent records of 371 distinct species, comprising 232 mammals, 132 birds, and seven reptiles. The total trapping effort accumulated in this data paper consisted of 876,606 trap nights, distributed among Indonesia, Singapore, Malaysia, Bhutan, Thailand, Myanmar, Cambodia, Laos, Vietnam, Nepal, and far eastern India. The relatively standardized deployment methods in the region provide a consistent, reliable, and rich count data set relative to other large-scale pressence-only data sets, such as the Global Biodiversity Information Facility (GBIF) or citizen science repositories (e.g., iNaturalist), and is thus most similar to eBird. To facilitate the use of these data, we also provide mammalian species trait information and 13 environmental covariates calculated at three spatial scales around the camera survey centroids (within 10-, 20-, and 30-km buffers). We will update the dataset to include broader coverage of temperate Asia and add newer surveys and covariates as they become available. This dataset unlocks immense opportunities for single-species ecological or conservation studies as well as applied ecology, community ecology, and macroecology investigations. The data are fully available to the public for utilization and research. Please cite this data paper when utilizing the data

CamTrapAsia: A dataset of tropical forest vertebrate communities from 239 camera trapping studies

Information on tropical Asian vertebrates has traditionally been sparse, particularly when it comes to cryptic species inhabiting the dense forests of the region. Vertebrate populations are declining globally due to land‐use change and hunting, the latter frequently referred as “defaunation.” This is especially true in tropical Asia where there is extensive land‐use change and high human densities. Robust monitoring requires that large volumes of vertebrate population data be made available for use by the scientific and applied communities. Camera traps have emerged as an effective, non‐invasive, widespread, and common approach to surveying vertebrates in their natural habitats. However, camera‐derived datasets remain scattered across a wide array of sources, including published scientific literature, gray literature, and unpublished works, making it challenging for researchers to harness the full potential of cameras for ecology, conservation, and management. In response, we collated and standardized observations from 239 camera trap studies conducted in tropical Asia. There were 278,260 independent records of 371 distinct species, comprising 232 mammals, 132 birds, and seven reptiles. The total trapping effort accumulated in this data paper consisted of 876,606 trap nights, distributed among Indonesia, Singapore, Malaysia, Bhutan, Thailand, Myanmar, Cambodia, Laos, Vietnam, Nepal, and far eastern India. The relatively standardized deployment methods in the region provide a consistent, reliable, and rich count data set relative to other large‐scale pressence‐only data sets, such as the Global Biodiversity Information Facility (GBIF) or citizen science repositories (e.g., iNaturalist), and is thus most similar to eBird. To facilitate the use of these data, we also provide mammalian species trait information and 13 environmental covariates calculated at three spatial scales around the camera survey centroids (within 10‐, 20‐, and 30‐km buffers). We will update the dataset to include broader coverage of temperate Asia and add newer surveys and covariates as they become available. This dataset unlocks immense opportunities for single‐species ecological or conservation studies as well as applied ecology, community ecology, and macroecology investigations. The data are fully available to the public for utilization and research. Please cite this data paper when utilizing the data

Environmental factors induced crop raiding by wild Asian elephant (Elephas maximus) in the Eastern Economic Corridor, Thailand

Abstract Crop raiding are an increasing concern in wildlife conservation. This study identified the environmental factors that cause wild Asian elephants (Elephas maximus) to enter sub-urban and rural areas and share resources with humans in the Eastern Economic Corridor (EEC) in the eastern part of Thailand. The snowball method was used to interview villagers that had crop raiding experienced in seven provinces of the EEC and adjacent provinces in the eastern part of Thailand in 2020, and data from 183 households indicated that crop raiding had increased continuously from 2000 to 2020, especially in Chonburi, Chachoengsao, and Prachinburi provinces, which have seen increases in damaged agricultural areas. MaxEnt analysis showed an increase in incidents of crop raiding, while the elephants distribution area decreased from 9534 km2 in 2000 to 5199 km2 in 2010 and 4850 km2 in 2020. The study area has had land use changes in the low elevations from croplands of cassava and sugar cane to eucalyptus, para rubber, and fruits. These mixed crop plantations provide a pseudo-habitat for wild Asian elephants. The results from this study provide evidence that changes in land use and reduction of suitable habitat are factors that influenced the movement of wild Asian elephants to the rural agricultural areas and increased the incidents of crop raiding

Some ecological aspects of dhole (Cuon alpinus) in the Huai Kha Khaeng Wildlife Sanctuary, Uthai Thani Province, Thailand

The dhole (Cuon alpinus) is one of the least frequent studied endangered canid species and many aspects of ecological knowledge about this species are lacking. The objectives of this study were to investigate the spatial movement of dholes, prey abundance, prey selection, and prey overlaps with other large carnivorous species in the Huai Kha Khaeng Wildlife Sanctuary, Thailand, during November, 2017 and October, 2018. Two adult female dholes were captured and fitted with GPS collars. Twenty camera trap sets were systematically used to survey the area. Scat collection was conducted along forest roads and trails. The home range sizes and activity radii of the two dholes were 3,151.63 ha. and 1,442.84 m, and 33.39 ha and 331.56 m, respectively. The sambar deer (Rusa unicolor) was the most abundant prey species (30.93%). However, dhole fecal analysis showed that the monitored dholes preferred red muntjac (Muntiacus muntjak) (57.1%). There was a high degree of prey overlap between dholes and leopards (98%), indicating very high prey competition. The dholes in this study represent movement patterns in richly abundant prey habitats, but with the presence of other predators that can affect prey selection and movement patterns of the dhole in the area

Habitat connectivity for endangered Indochinese tigers in Thailand

Habitat connectivity is crucial for the conservation of species restricted to fragmented populations within human-dominated landscapes. However, identifying habitat connectivity for apex predators is challenging because trophic interactions between primary productivity and prey species influence both the distribution of habitats, and predator movement. Our goal was to assess habitat connectivity for Indochinese tigers (Panthera tigris) in Thailand. We quantified suitable habitat and dispersal corridors based an ensemble species distribution model that included prey distributions, primary productivity, and abiotic variables and was based on camera-trap data from 1996 to 2013 in 15 protected areas. We employed graph theory to evaluate the relative importance of habitat patches and dispersal corridors to the overall connectivity network. We found that tiger occurrence models with and without prey distributions performed well (Area Under the Curve: 0.932–0.954). However, inclusion of prey distributions significantly improved model performance (P < 0.001). Protected areas with tigers at the time of our surveys were highly isolated with high resistance to movement within the dispersal corridors, and four of them have lost their tiger populations since. Potential habitat patches outside of protected areas were also mostly isolated, but it was encouraging to find that there is ample potential habitat that tigers are not occupying. The Huai Kha Kaeng - ThungYai habitat patch and Kaeng Krachan dispersal corridor were the most important for overall habitat connectivity. Generally, integrating prey distributions into assessments of connectivity is a promising approach that can be widely applied to predict species occurrence and delineate dispersal corridors, thereby supporting conservation planning of tigers and other large carnivores

Using global remote camera data of a solitary species complex to evaluate the drivers of group formation

The social system of animals involves a complex interplay between physiology, natural history, and the environment. Long relied upon discrete categorizations of "social" and "solitary" inhibit our capacity to understand species and their interactions with the world around them. Here, we use a globally distributed camera trapping dataset to test the drivers of aggregating into groups in a species complex (martens and relatives, family , Order ) assumed to be obligately solitary. We use a simple quantification, the probability of being detected in a group, that was applied across our globally derived camera trap dataset. Using a series of binomial generalized mixed-effects models applied to a dataset of 16,483 independent detections across 17 countries on four continents we test explicit hypotheses about potential drivers of group formation. We observe a wide range of probabilities of being detected in groups within the solitary model system, with the probability of aggregating in groups varying by more than an order of magnitude. We demonstrate that a species' context-dependent proclivity toward aggregating in groups is underpinned by a range of resource-related factors, primarily the distribution of resources, with increasing patchiness of resources facilitating group formation, as well as interactions between environmental conditions (resource constancy/winter severity) and physiology (energy storage capabilities). The wide variation in propensities to aggregate with conspecifics observed here highlights how continued failure to recognize complexities in the social behaviors of apparently solitary species limits our understanding not only of the individual species but also the causes and consequences of group formation

Using global remote camera data of a solitary species complex to evaluate the drivers of group formation

The social system of animals involves a complex interplay between physiology, natural history, and the environment. Long relied upon discrete categorizations of "social" and "solitary" inhibit our capacity to understand species and their interactions with the world around them. Here, we use a globally distributed camera trapping dataset to test the drivers of aggregating into groups in a species complex (martens and relatives, family , Order ) assumed to be obligately solitary. We use a simple quantification, the probability of being detected in a group, that was applied across our globally derived camera trap dataset. Using a series of binomial generalized mixed-effects models applied to a dataset of 16,483 independent detections across 17 countries on four continents we test explicit hypotheses about potential drivers of group formation. We observe a wide range of probabilities of being detected in groups within the solitary model system, with the probability of aggregating in groups varying by more than an order of magnitude. We demonstrate that a species' context-dependent proclivity toward aggregating in groups is underpinned by a range of resource-related factors, primarily the distribution of resources, with increasing patchiness of resources facilitating group formation, as well as interactions between environmental conditions (resource constancy/winter severity) and physiology (energy storage capabilities). The wide variation in propensities to aggregate with conspecifics observed here highlights how continued failure to recognize complexities in the social behaviors of apparently solitary species limits our understanding not only of the individual species but also the causes and consequences of group formation