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remain scattered across a wide array of sources, including published scientific literature, gray literature, and unpublished works, making it challenging for researchers to harness the full potential of cameras for ecology, conservation, and management.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.

Logged tropical forests have amplified and diverse ecosystem energetics.

Old-growth tropical forests are widely recognized as being immensely important for their biodiversity and high biomass1. Conversely, logged tropical forests are usually characterized as degraded ecosystems2. However, whether logging results in a degradation in ecosystem functions is less clear: shifts in the strength and resilience of key ecosystem processes in large suites of species have rarely been assessed in an ecologically integrated and quantitative framework. Here we adopt an ecosystem energetics lens to gain new insight into the impacts of tropical forest disturbance on a key integrative aspect of ecological function: food pathways and community structure of birds and mammals. We focus on a gradient spanning old-growth and logged forests and oil palm plantations in Borneo. In logged forest there is a 2.5-fold increase in total resource consumption by both birds and mammals compared to that in old-growth forests, probably driven by greater resource accessibility and vegetation palatability. Most principal energetic pathways maintain high species diversity and redundancy, implying maintained resilience. Conversion of logged forest into oil palm plantation results in the collapse of most energetic pathways. Far from being degraded ecosystems, even heavily logged forests can be vibrant and diverse ecosystems with enhanced levels of ecological function.

Food availability alters community co-occurrence patterns at fine spatiotemporal scales in a tropical masting system.

Patterns of co-occurrence among species can help reveal the structure and assembly of ecological communities. However, studies have been limited by measuring co-occurrence in either space or time but not both simultaneously. This is especially problematic in systems such as masting forests where resources are highly variable, meaning that spatial use and co-occurrence patterns can change on fine spatiotemporal scales. We develop an analytical framework for assessing species co-occurrence at fine spatial and temporal scales simultaneously and apply these models to a camera trapping dataset from Borneo. We sought to determine how substantial variation in food availability across space and time affects co-occurrence among terrestrial vertebrates. We detect many significant, mostly positive, co-occurrence patterns among species, but almost entirely in unlogged forest and during dipterocarp mast years. The most strongly co-occurring pair of species, bearded pig (Sus barbatus) and sambar (Rusa unicolor), only positively co-occur in areas and years when fruit is locally abundant. Species occurrences in logged forest and non-mast years are mostly random with respect to other species. This suggests that frugivore-granivore species positively co-occur when resources are plentiful (i.e., large trees are present and fruiting), likely because they use the same resources; these patterns disappear when food availability is lower. Our approach demonstrates the utility of measuring co-occurrence in space and time together and highlights the importance of resource abundance for driving the co-occurrence structure of communities. Furthermore, our method could be broadly applied to other systems to assess fine-scale spatiotemporal patterns across a range of taxa.

Temporal activity patterns suggesting niche partitioning of sympatric carnivores in Borneo, Malaysia.

To propose proper conservation measures and to elucidate coexistence mechanisms of sympatric carnivore species, we assessed temporal activity patterns of the sympatric carnivore species using 37,379 photos collected for more than 3 years at three study sites in Borneo. We categorized activity patterns of nine carnivore species (one bear, three civets, two felids, one skunk, one mustelid, one linsang) by calculating the photo-capturing proportions at each time period (day, night, twilight). We then evaluated temporal activity overlaps by calculating the overlap coefficients. We identified six nocturnal (three civets, one felid, one skunk, one linsang), two diurnal (one felid, one mustelid), and one cathemeral (bear) species. Temporal activity overlaps were high among the nocturnal species. The two felid species possessing morphological and ecological similarities exhibited clear temporal niche segregation, but the three civet species with similar morphology and ecology did not. Broad dietary breadth may compensate for the high temporal niche overlaps among the nocturnal species. Despite the high species richness of Bornean carnivores, almost half are threatened with extinction. By comparing individual radio-tracking and our data, we propose that a long-term study of at least 2 or 3 years is necessary to understand animals' temporal activity patterns, especially for sun bears and civets, by camera-trapping and to establish effective protection measures.

Fungal communities in bat guano, speleothem surfaces, and cavern water in Madai cave, Northern Borneo (Malaysia).

The island of Borneo is a global biodiversity hotspot. However, its limestone caves are one of its least-studied ecosystems. We report for the first time the fungal species richness, diversity and abundance from Madai cave, situated in north-eastern Borneo. Environmental samples from inside the cave environment were collected (guano, speleothem, and cavern water) via opportunistic sampling. The dilution method was performed for isolation of fungi. Morphological characterisation and molecular analysis of the ITS region were utilised for the identification of isolates. Fifty-five pure cultures of fungi were attained, comprising 32 species from 15 genera, eight orders, and two divisions, Ascomycota and Basidiomycota. Ascomycetes dominated the fungal composition, accounting for 53 (96%) out of 55 total isolates. Penicillium spp. accounted for more than 47.1% of fungal abundance in all sample types. However, Aspergillus spp. had the highest occurrence rate, being isolated from all environmental samples except one. Purpureocillium lilacinum was isolated most frequently, appearing in five separate samples across all three substrates. Annulohypoxylon nitens, Ganoderma australe, Pyrrhoderma noxium, and Xylaria feejeensis were discovered and reported for the first time from the cave environment. This study provides additional data for further research on the mycoflora of Sabah's various ecosystems, especially limestone caves.

Leech blood-meal invertebrate-derived DNA reveals differences in Bornean mammal diversity across habitats.

The application of metabarcoding to environmental and invertebrate-derived DNA (eDNA and iDNA) is a new and increasingly applied method for monitoring biodiversity across a diverse range of habitats. This approach is particularly promising for sampling in the biodiverse humid tropics, where rapid land-use change for agriculture means there is a growing need to understand the conservation value of the remaining mosaic and degraded landscapes. Here we use iDNA from blood-feeding leeches (Haemadipsa picta) to assess differences in mammalian diversity across a gradient of forest degradation in Sabah, Malaysian Borneo. We screened 557 individual leeches for mammal DNA by targeting fragments of the 16S rRNA gene and detected 14 mammalian genera. We recorded lower mammal diversity in the most heavily degraded forest compared to higher quality twice logged forest. Although the accumulation curves of diversity estimates were comparable across these habitat types, diversity was higher in twice logged forest, with more taxa of conservation concern. In addition, our analysis revealed differences between the community recorded in the heavily logged forest and that of the twice logged forest. By revealing differences in mammal diversity across a human-modified tropical landscape, our study demonstrates the value of iDNA as a noninvasive biomonitoring approach in conservation assessments.

Maximizing the value of forest restoration for tropical mammals by detecting three-dimensional habitat associations.

Tropical forest ecosystems are facing unprecedented levels of degradation, severely compromising habitat suitability for wildlife. Despite the fundamental role biodiversity plays in forest regeneration, identifying and prioritizing degraded forests for restoration or conservation, based on their wildlife value, remains a significant challenge. Efforts to characterize habitat selection are also weakened by simple classifications of human-modified tropical forests as intact vs. degraded, which ignore the influence that three-dimensional (3D) forest structure may have on species distributions. Here, we develop a framework to identify conservation and restoration opportunities across logged forests in Borneo. We couple high-resolution airborne light detection and ranging (LiDAR) and camera trap data to characterize the response of a tropical mammal community to changes in 3D forest structure across a degradation gradient. Mammals were most responsive to covariates that accounted explicitly for the vertical and horizontal characteristics of the forest and actively selected structurally complex environments comprising tall canopies, increased plant area index throughout the vertical column, and the availability of a greater diversity of niches. We show that mammals are sensitive to structural simplification through disturbance, emphasizing the importance of maintaining and enhancing structurally intact forests. By calculating occurrence thresholds of species in response to forest structural change, we identify areas of degraded forest that would provide maximum benefit for multiple high-conservation value species if restored. The study demonstrates the advantages of using LiDAR to map forest structure, rather than relying on overly simplistic classifications of human-modified tropical forests, for prioritizing regions for restoration.

Factors influencing riverine utilization patterns in two sympatric macaques.

Many species of terrestrial animals, including primates, live in varied association with the aquatic (e.g., riverine or coastal) environment. However, the benefits that each species receive from the aquatic environment are thought to vary depending on their social and ecological characteristics, and thus, elucidating those benefits to each species is important for understanding the principles of wild animal behaviour. In the present study, to gain a more complete picture of aquatic environment use, including social and ecological factors in primates, factors affecting riverine habitat utilization of two macaque species (Macaca nemestrina and M. fascicularis) were identified and qualitative comparisons were made with sympatric proboscis monkeys (Nasalis larvatus), which have different social and ecological characteristics. Temporal variation in sighting frequency of macaques at the riverbanks was positively related to the fruit availability of a dominant riparian plant species and negatively related to the river water level which affects the extent of predation pressure. Riverine utilization of macaques was greatly influenced by distribution and abundance of food (especially fruit) resources, possibly in association with predation pressure. Additionally, qualitative ecological comparisons with sympatric proboscis monkeys suggest that the drivers of riverine utilization depend on the feeding niches of the species, and different anti-predator strategies resulting from their differing social structures.

Habitat use by a primate community in a lowland dipterocarp forest in Danum Valley, Borneo.

Knowledge of niche partitioning with respect to habitat is indispensable to understand the mechanism of coexistence of multiple species. Among primates, however, data are still deficient because repeated survey for a sufficiently long time, covering seasonal changes over a large area, is the only way to clarify habitat segregation within a seasonally fluctuating environment. Southeast Asia is particularly interesting because of the supra-annual, highly unpredictable seasonality in fruiting known as mast fruiting. We conducted repeated route census, habitat monitoring, and group tracking for 25 months in two study sites (ca. 10 km apart) in the largely primary lowland dipterocarp forest of the Danum Valley Conservation Area, eastern Sabah, northern Borneo, Malaysia. The five species of diurnal primates (Bornean orangutan Pongo pygmaeus, Müeller's gibbon Hylobates muelleri, red leaf monkey Presbytis rubicunda, long-tailed macaque Macaca fascicularis, and southern pig-tailed macaque M. nemestrina) did not show horizontal spatial segregation. Red leaf monkeys showed preferences for places with short tree height, but their distribution was not confined to such places. In response to the fruiting peak observed once during the study period, orangutans increased their numbers simultaneously in the two study sites. The average tree height used by the five species was different, but their range overlapped substantially. Compared with other primate communities, the lack of horizontal spatial segregation and the suggested long-distance movement of orangutans seem to be unique characteristics in Borneo, although the use of different forest strata is a widespread phenomenon among primate communities throughout the world.

Vertebrate Scavengers Control Abundance of Diarrhea-causing Bacteria in Tropical Plantations.

Scavenging is a common phenomenon, particularly amongst carnivorous vertebrates. By consuming carrion, vertebrate scavengers reduce resource availability for both pathogenic bacteria and their insect vectors. We investigated the ability of wild vertebrate scavengers to control agents of human diarrheal diseases (specifically Salmonella spp. and Shiga toxin-producing Escherichia coli [STEC]) in oil palm plantations in Sabah (East Malaysia), and the existence of spillover effect whereby additional vertebrate scavengers from adjacent forest patches result in greater disease control in plantation sections near these forest edges. Experimental carcasses were removed by common scavengers (Varanus salvator, Canis lupus familiaris, and Viverra tangalunga) at different time points, and this determined the length of time that the carcasses persisted in the environment. The amount of pathogenic bacteria on the surfaces of filth flies collected above the experimental carcasses was positively correlated to the duration of carcass persistence, and reduction in pathogenic bacterial abundances was largely due to carcass consumption by these vertebrate scavengers. Instead of a predicted positive spillover effect (greater scavenger activity near forest edges, hence reduced pathogen abundance), we detected a weak inverse spillover effect in which STEC counts were marginally higher in plantation sections near forest patches, and human hunting along the forest-plantation boundaries could explain this. We propose that making oil palm plantations scavenger-friendly could yield great human health benefits for the millions of workers employed in this rapidly-expanding industry, without drastically changing current management practices.

Densities of Bornean orang-utans (Pongo pygmaeus morio) in heavily degraded forest and oil palm plantations in Sabah, Borneo.

The conversion of forest to agriculture continues to contribute to the loss and fragmentation of remaining orang-utan habitat. There are still few published estimates of orang-utan densities in these heavily modified agricultural areas to inform range-wide population assessments and conservation strategies. In addition, little is known about what landscape features promote orang-utan habitat use. Using indirect nest count methods, we implemented surveys and estimated population densities of the Northeast Bornean orang-utan (Pongo pygmaeus morio) across the continuous logged forest and forest remnants in a recently salvage-logged area and oil palm plantations in Sabah, Malaysian Borneo. We then assessed the influence of landscape features and forest structural metrics obtained from LiDAR data on estimates of orang-utan density. Recent salvage logging appeared to have a little short-term effect on orang-utan density (2.35 ind/km 2 ), which remained similar to recovering logged forest nearby (2.32 ind/km 2 ). Orang-utans were also present in remnant forest patches in oil palm plantations, but at significantly lower numbers (0.82 ind/km 2 ) than nearby logged forest and salvage-logged areas. Densities were strongly influenced by variation in canopy height but were not associated with other potential covariates. Our findings suggest that orang-utans currently exist, at least in the short-term, within human-modified landscapes, providing that remnant forest patches remain. We urge greater recognition of the role that these degraded habitats can have in supporting orang-utan populations, and that future range-wide analyses and conservation strategies better incorporate data from human-modified landscapes.

The influence of logging on vertebrate responses to mast fruiting.

Periods of extreme food abundance, such as irregular masting events, can dramatically affect animal populations and communities, but the extent to which anthropogenic disturbances alter animal responses to mast events is not clear. In South-East Asia, dipterocarp trees reproduce in mast fruiting events every 2-10 years in some of the largest masting events on the planet. These trees, however, are targeted for selective logging, reducing the intensity of fruit production and potentially affecting multiple trophic levels. Moreover, animal responses to resource pulse events have largely been studied in systems where the major mast consumers have been extirpated. We sought to evaluate the influence of human-induced habitat disturbance on animal responses to masting in a system where key mast consumers remain extant. We used motion-triggered camera traps to quantify terrestrial mammal and bird occurrences in Sabah, Malaysian Borneo, relative to variation in fruit biomass from 69 plant families during a major (2014) and minor (2015) masting event and a non-mast year (2013), in both logged and unlogged forests. Bearded pigs (Sus barbatus) showed the clearest responses to masting and occurrence rates were highest in unlogged forest in the year following the major mast, suggesting that the pulse in fruit availability increased immigration or reproduction. We also detected local-scale spatial tracking of dipterocarp fruits in bearded pigs in unlogged forest, while this was equivocal in other species. In contrast, pigs and other vertebrate taxa in our study showed limited response to spatial or temporal variation in fruit availability in logged forest. Our findings suggest that vertebrates, namely bearded pigs, may respond to masting via movement and increased reproduction, but that these responses may be attenuated by habitat disturbance.

Land-use change alters the mechanisms assembling rainforest mammal communities in Borneo.

The assembly of species communities at local scales is thought to be driven by environmental filtering, species interactions and spatial processes such as dispersal limitation. Little is known about how the relative balance of these drivers of community assembly changes along environmental gradients, especially man-made environmental gradients associated with land-use change. Using concurrent camera- and live-trapping, we investigated the local-scale assembly of mammal communities along a gradient of land-use intensity (old-growth forest, logged forest and oil palm plantations) in Borneo. We hypothesised that increasing land-use intensity would lead to an increasing dominance of environmental control over spatial processes in community assembly. Additionally, we hypothesised that competitive interactions among species might reduce in concert with declines in α-diversity (previously documented) along the land-use gradient. To test our first hypothesis, we partitioned community variance into the fractions explained by environmental and spatial variables. To test our second hypothesis, we used probabilistic models of expected species co-occurrence patterns, in particular focussing on the prevalence of spatial avoidance between species. Spatial avoidance might indicate competition, but might also be due to divergent habitat preferences. We found patterns that are consistent with a shift in the fundamental mechanics governing local community assembly. In support of our first hypothesis, the importance of spatial processes (dispersal limitation and fine-scale patterns of home-ranging) appeared to decrease from low to high intensity land-uses, whilst environmental control increased in importance (in particular due to fine-scale habitat structure). Support for our second hypothesis was weak: whilst we found that the prevalence of spatial avoidance decreased along the land-use gradient, in particular between congeneric species pairs most likely to be in competition, few instances of spatial avoidance were detected in any land-use, and most were likely due to divergent habitat preferences. The widespread changes in land-use occurring in the tropics might be altering not just the biodiversity found in landscapes, but also the fundamental mechanics governing the local assembly of communities. A better understanding of these mechanics, for a range of taxa, could underpin more effective conservation and management of threatened tropical landscapes.

Using metabarcoding to compare the suitability of two blood-feeding leech species for sampling mammalian diversity in North Borneo.

The application of high-throughput sequencing (HTS) for metabarcoding of mixed samples offers new opportunities in conservation biology. Recently, the successful detection of prey DNA from the guts of leeches has raised the possibility that these, and other blood-feeding invertebrates, might serve as useful samplers of mammals. Yet little is known about whether sympatric leech species differ in their feeding preferences, and whether this has a bearing on their relative suitability for monitoring local mammalian diversity. To address these questions, we collected spatially matched samples of two congeneric leech species Haemadipsa picta and Haemadipsa sumatrana from lowland rainforest in Borneo. For each species, we pooled ~500 leeches into batches of 10 individuals, performed PCR to target a section of the mammalian 16S rRNA locus and undertook sequencing of amplicon libraries using an Illumina MiSeq. In total, we identified sequences from 14 mammalian genera, spanning nine families and five orders. We found greater numbers of detections, and higher diversity of OTUs, in H. picta compared with H. sumatrana, with rodents only present in the former leech species. However, comparison of samples from across the landscape revealed no significant difference in mammal community composition between the leech species. We therefore suggest that H. picta is the more suitable iDNA sampler in this degraded Bornean forest. We conclude that the choice of invertebrate sampler can influence the detectability of different mammal groups and that this should be accounted for when designing iDNA studies.

Multiple stages of tree seedling recruitment are altered in tropical forests degraded by selective logging.

Tropical forest degradation is a global environmental issue. In degraded forests, seedling recruitment of canopy trees is vital for forest regeneration and recovery. We investigated how selective logging, a pervasive driver of tropical forest degradation, impacts canopy tree seedling recruitment, focusing on an endemic dipterocarp Dryobalanops lanceolata in Sabah, Borneo. During a mast-fruiting event in intensively logged and nearby unlogged forest, we examined four stages of the seedling recruitment process: seed production, seed predation, and negative density-dependent germination and seedling survival. Our results suggest that each stage of the seedling recruitment process is altered in logged forest. The seed crop of D. lanceolata trees in logged forest was one-third smaller than that produced by trees in unlogged forest. The functional role of vertebrates in seed predation increased in logged forest while that of non-vertebrates declined. Seeds in logged forest were less likely to germinate than those in unlogged forest. Germination increased with local-scale conspecific seed density in unlogged forest, but seedling survival tended to decline. However, both germination and seedling survival increased with local-scale conspecific seed density in logged forest. Notably, seed crop size, germination, and seedling survival tended to increase for larger trees in both unlogged and logged forests, suggesting that sustainable timber extraction and silvicultural practices designed to minimize damage to the residual stand are important to prevent seedling recruitment failure. Overall, these impacts sustained by several aspects of seedling recruitment in a mast-fruiting year suggest that intensive selective logging may affect long-term population dynamics of D. lanceolata. It is necessary to establish if other dipterocarp species, many of which are threatened by the timber trade, are similarly affected in tropical forests degraded by intensive selective logging.

The combined impacts of experimental defaunation and logging on seedling traits and diversity.

Animals can have both positive (e.g. via seed dispersal) and negative (e.g. via herbivory) impacts on plants. The net effects of these interactions remain difficult to predict and may be affected by overhunting and habitat disturbance, two widespread threats to tropical forests. Recent studies have documented their separate effects on plant recruitment but our understanding of how defaunation and logging interact to influence tropical tree communities is limited. From 2013 to 2016, we followed the fate of marked tree seedlings (n = 1489) from 81 genera in and outside experimental plots. Our plots differentially excluded small, medium and large-bodied mammal herbivores in logged and unlogged forest in Malaysian Borneo. We assessed the effects of experimental defaunation and logging on taxonomic diversity and plant trait (wood density, specific leaf area, fruit size) composition of seedling communities. Although seedling mortality was highest in the presence of all mammal herbivores (44%), defaunation alone did not alter taxonomic diversity nor plant trait composition. However, herbivores (across all body sizes) significantly reduced mean fruit size across the seedling community over time (95% confidence interval (CI): -0.09 to -0.01), particularly in logged forest (95% CI: -0.12 to -0.003). Our findings suggest that impacts of mammal herbivores on plant communities may be greater in forests with a history of disturbance and could subsequently affect plant functional traits and ecological processes associated with forest regeneration.

Defaunation and habitat disturbance interact synergistically to alter seedling recruitment.

Vertebrate granivores destroy plant seeds, but whether animal-induced seed mortality alters plant recruitment varies with habitat context, seed traits, and among granivore species. An incomplete understanding of seed predation makes it difficult to predict how widespread extirpations of vertebrate granivores in tropical forests might affect tree communities, especially in the face of habitat disturbance. Many tropical forests are simultaneously affected by animal loss as well as habitat disturbance, but the consequences of each for forest regeneration are often studied separately or additively, and usually on a single plant demographic stage. The combined impacts of these threats could affect plant recruitment in ways that are not apparent when studied in isolation. We used wire cages to exclude large (elephants), medium, (sambar deer, bearded pigs, muntjac deer), and small (porcupines, chevrotains) ground-dwelling mammalian granivores and herbivores in logged and unlogged forests in Malaysian Borneo. We assessed the interaction between habitat disturbance (selective logging) and experimental defaunation on seed survival, germination, and seedling establishment in five dominant dipterocarp tree species spanning a 21-fold gradient in seed size. Granivore-induced seed mortality was consistently higher in logged forest. Germination of unpredated seeds was reduced in logged forest and in the absence of small to large-bodied mammals. Experimental defaunation increased germination and reduced seed removal but had little effect on seed survival. Seedling recruitment however, was more likely where logging and animal loss occurred together. The interacting effects of logging and hunting could therefore, actually increase seedling establishment, suggesting that the loss of mammals in disturbed forest could have important consequences for forest regeneration and composition.

Seasonal Fluctuations of Astrovirus, But Not Coronavirus Shedding in Bats Inhabiting Human-Modified Tropical Forests.

Emerging infectious diseases (EIDs) are considered a major threat to global health. Most EIDs appear to result from increased contact between wildlife and humans, especially when humans encroach into formerly pristine habitats. Habitat deterioration may also negatively affect the physiology and health of wildlife species, which may eventually lead to a higher susceptibility to infectious agents and/or increased shedding of the pathogens causing EIDs. Bats are known to host viruses closely related to important EIDs. Here, we tested in a paleotropical forest with ongoing logging and fragmentation, whether habitat disturbance influences the occurrence of astro- and coronaviruses in eight bat species. In contrast to our hypothesis, anthropogenic habitat disturbance was not associated with corona- and astrovirus detection rates in fecal samples. However, we found that bats infected with either astro- or coronaviruses were likely to be coinfected with the respective other virus. Additionally, we identified two more risk factors influencing astrovirus shedding. First, the detection rate of astroviruses was higher at the beginning of the rainy compared to the dry season. Second, there was a trend that individuals with a poor body condition had a higher probability of shedding astroviruses in their feces. The identification of risk factors for increased viral shedding that may potentially result in increased interspecies transmission is important to prevent viral spillovers from bats to other animals, including humans.

Increasing land-use intensity reverses the relative occupancy of two quadrupedal scavengers.

Human land use is continuously altering the natural environment, yet the greater ecological implications of this change for many groups that are key to healthy ecosystem functioning remains uncharacterised in the tropics. Terrestrial scavenging vertebrates are one such group, providing integral ecosystem services through the removal of carrion which is a crucial component of both nutrient cycling and disease dynamics. To explore how anthropogenic processes may affect forest scavengers, we investigated the changes in the relative occupancy of two important terrestrial scavengers along a gradient of land use intensity, ranging from protected forest to oil palm plantation in Borneo. We found the Malay civet (Viverra tangalunga) had highest, albeit variable, occupancy in areas of low land use intensity and the Southeast Asian water monitor (Varanus salvator macromaculatus) had highest occupancy in areas of high land use intensity. Land use had no effect on the combined occupancy of the two species. In high land use intensity sites, individual water monitors were larger and had better body condition, but at population level had a highly biased sex ratio with more males than females and increased signs of intraspecific conflict. We did not assess scavenging rate or efficiency as a process, but the high occupancy rates and apparent health of the scavengers in high land use intensity landscapes suggests this ecological process is robust to land use change.