The rise of hyperabundant native generalists threatens both humans and nature

In many disturbed terrestrial landscapes, a subset of native generalist vertebrates thrives. The population trends of these disturbance-tolerant species may be driven by multiple factors, including habitat preferences, foraging opportunities (including crop raiding or human refuse), lower mortality when their predators are persecuted (the ‘human shield’ effect) and reduced competition due to declines of disturbance-sensitive species. A pronounced elevation in the abundance of disturbance-tolerant wildlife can drive numerous cascading impacts on food webs, biodiversity, vegetation structure and people in coupled human–natural systems. There is also concern for increased risk of zoonotic disease transfer to humans and domestic animals from wildlife species with high pathogen loads as their abundance and proximity to humans increases. Here we use field data from 58 landscapes to document a supra-regional phenomenon of the hyperabundance and community dominance of Southeast Asian wild pigs and macaques. These two groups were chosen as prime candidates capable of reaching hyperabundance as they are edge adapted, with gregarious social structure, omnivorous diets, rapid reproduction and high tolerance to human proximity. Compared to intact interior forests, population densities in degraded forests were 148% and 87% higher for wild boar and macaques, respectively. In landscapes with >60% oil palm coverage, wild boar and pig-tailed macaque estimated abundances were 337% and 447% higher than landscapes with 20% oil palm cover where two pig and two macaque species accounted for >80% of independent camera trap detections, leaving 1 kg considered. Establishing the population trends of pigs and macaques is imperative since they are linked to cascading impacts on the fauna and flora of local forest ecosystems, disease and human health, and economics (i.e., crop losses). The severity of potential negative cascading effects may motivate control efforts to achieve ecosystem integrity, human health and conservation objectives. Our review concludes that the rise of native generalists can be mediated by specific types of degradation, which influences the ecology and conservation of natural areas, creating both positive and detrimental impacts on intact ecosystems and human society

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

Dominance hierarchy on palm resource partitioning among Neotropical frugivorous mammals

In tropical forests, the diets of many frugivorous mammals overlap, yet how hyper-diverse assemblages of consumers exploit resources and coexist remains poorly understood. We evaluated competitive interactions among three species of terrestrial frugivorous mammals, the ungulate Tayassu pecari (white-lipped peccary), its close relative Pecari tajacu (collared peccary), and a large rodent (Dasyprocta azarae, agouti), in their exploitation strategies of palm resources of different quality. We conducted the study in a large isolated fragment at the tropical Atlantic Forest of Brazil, where these mammal species show high spatial and temporal overlap. We evaluated if body mass and foraging group size define a hierarchy in exploitation of preferentially richer palm resources. We used camera traps and two-species occupancy models to examine patterns of co-occurrence and variable interaction strength between these consumers and three species of palms. Our analyses supported the hypothesis of partial resource overlap but no competition among frugivores, and a body mass dominance hierarchical exploitation of resources. The larger frugivore (white-lipped peccary) dominated patches of the lipid-rich palm Euterpe edulis, where the smallest frugivore (agouti) was absent. Instead, the smallest frugivore concentrated its foraging in areas with the poorest palm resource, Syagrus oleracea. Collared peccaries preferred areas of high abundance of Syagrus romanzoffiana when the other two mammal species were rarely detected or absent, strongly avoided patches of E. edulis, and showed higher average detection probabilities when agoutis were present. Our study highlights the important role of behavioral plasticity in promoting coexistence and indicates that through context-dependent interactions and hierarchical partitioning of resources, consumers can avoid strong competition, even under conditions of high spatial and temporal overlap and high levels of habitat fragmentation and isolation

Mid-sized felids threatened by habitat degradation in Southeast Asia

Deforestation and poaching in Southeast Asia have driven a stark decline in the region's apex predators, including large felids like tigers and leopards. Meanwhile, some small felids thrive in the region's human-modified landscapes. The extent to which medium-sized felids cope with anthropogenic disturbances remains poorly understood, but this information is crucial for the conservation of threatened felids and key trophic interactions that maintain high-diversity food webs. Here, we use the largest camera-trap dataset from Southeast Asia to conduct a multi-scale synthesis of the habitat associations of two cryptic felids, the Near-Threatened Asiatic golden cat (Catopuma temminckii) and the Endangered bay cat (Catopuma badia). Unlike many mesopredators, both species exhibited poor tolerance to habitat degradation (i.e. selective logging, edges or fragmentation). The golden cat was positively associated with forest patch size and elevation, and negatively associated with degraded forests, and the bay cat was negatively associated with human population density. Our habitat suitability model suggests that ongoing forest fragmentation and degradation have critically reduced suitable habitat for the golden cat, giving reason to suspect a population decline that calls for a revision of the species' IUCN Red List status to Vulnerable. There is also evidence that the bay cat may be more widely distributed in Borneo than previously thought, including in areas currently threatened by deforestation. Our results indicate both species face a high risk of becoming extirpated from many of the region's remaining forests. In areas where apex predators have been extirpated, these charismatic mid-sized felids can become umbrella species to protect forests with high biodiversity value.Nanyang Technological UniversityPublished versionThe research was funded by the Smithsonian Institution 's ForestGEO program, Nanyang Technological University in Singapore, the University of Queensland, National Geographic Society's Committee for the Research and Exploration award # 9384–13 and Matthew Scott Luskin was supported by an Australian Research Council Discovery Early Career Researcher Award DECRA # DE210101440. In-kind support in was provided by FFI, TEAM, WCS, the Leuser International Foundation, and SEARRP

Invasive wild boar's distribution overlap with threatened native ungulate in Patagonia

Wild boar (Sus scrofa) is one of the most damaging invasive species in the world and can have a profound impact on the distribution of native species. Nevertheless, there still are limitations on the species' current fine-scale spatial information, which is needed to develop effective management measures. Here, we used Species Distribution Models (SDMs) and niche overlap analysis to estimate potential conflict areas between the wild boar and the native southern pudu (Pudu puda), which is a bioindicator of the forest conservation status within the Nahuel Huapi National Park (NHNP), Argentina. The two species' environmental niche overlaps by 40%, which results in a wide geographical overlap between wild boar and pudu distributions. The distribution model predicted that the wild boar potential distribution occupies 22% of the national park and overlaps up to 67% with the pudu distribution, which in turn occupies 20% of the park. Based on our models, we classified 12% of the park as extreme management priority areas, because both species are present. High priority areas, where wild boars have the potential to invade but will not overlap with pudu populations, represent 10% of the park. Medium priority areas, where wild boars do not threaten pudu populations, and low priority areas, with no potential presence of either species, are 8% and 68%, respectively. The results of this study show how SDMs developed at local scales can support the management and monitoring of native and invasive species and help guide the allocation of efforts and resources for management actions focused on protected areas

A question of size and fear: competition and predation risk perception among frugivores and predators

Mammalian spatial and temporal activity patterns can vary depending on foraging behavior or the perception of predation or competition risk among species. These behaviors may in turn be altered by human influences such as defaunation. Herein, we evaluate whether frugivores avoid areas with high visitation rates by potential predators or competitors, and whether this avoidance changes in areas with different degrees of defaunation. We installed 189 cameras under fruit trees in six areas of the Atlantic Forest, Brazil, that differ in the abundance of top predators and large frugivores. Small predators and small frugivores were more frequent at night while large frugivores were more frequent during the day, but small frugivores visited and spent less time at fruiting trees on brighter nights, unlike large predators and large frugivores. Small frugivores also were less frequent in areas with high visitation by large frugivores and more frequent in highly defaunated areas. Our results suggest that the dynamics among mammalian functional groups varied according to diel patterns, potential competitors, and defaunation. We highlight the importance of understanding how species interactions are changing in areas exposed to strong human impacts to mitigate the indirect effects of defaunation

Landscape of human fear in Neotropical rainforest mammals

The landscape of fear has profound effects on the species behavior, with most organisms engaging in risk avoidance behaviors in areas perceived as riskier. Most risk avoidance behaviors, such as temporal avoidance, have severe trade-offs between foraging efficiency and risk reduction. Human activities are able to affect the species landscape of fear, by increasing mortality of individuals (i.e. hunting, roadkill) and by disruption of the clues used by the species to estimate predation risk (e.g. light pollution). In this study, we used an extensive camera-trapping and night-time light satellite imagery to evaluate whether human activities affect the diel activity patterns of 17 species of rainforest dwelling mammals. We found evidence of diel activity shifts in eight of 17 analyzed species, in which five species become 21.6 % more nocturnal and three species become 11.7% more diurnal in high disturbed areas. This activity shifts were observed for both diurnal and nocturnal species. Persecuted species (game and predators) were more susceptible to present activity shifts. Since changes in foraging activity may affect species fitness, the behavior of humans’ avoidance may be another driver of the Anthropocene defaunation

Processos de recuperação em áreas afetadas por mineração: uma revisão cienciométrica

A major challenge in using recovery techniques, for the different natural ecosystems affected by mining, is a mutual relationship between the habitat and its biota response. This study aimed to do a review to identify the number of publications, which countries are publishing more and which recovery techniques and taxonomic group are used in mining areas globally have contributed to the maintenance or recovery of the environment. We reviewed the literature on recovery in mining areas worldwide, between 1994 and 2016, using the Web of Science online database. We identified 9,000 publications, after the selection procedures, we analyzed the 467 remaining manuscripts. Of these, 34.26% were published between 1994 and 2004, and 65.74% between 2006 and 2016. The countries that contributed the most were the USA with 16.45%, Australia with 13.56% and China with 8.66%. Brazil contributed 6.9% of the publications. The recovery techniques using vegetation were the most reported in the literature and most used. The taxonomic group of terrestrial plants was the most cited and most used in the recovery of degraded areas. We found various techniques for recovering degraded areas can be established, but most of them did not show proper monitoring and without this the recovery processes may not achieve their objectives and studies that test the effect size of these recovery methods are still necessary.Um grande desafio no uso de técnicas de recuperação, para os diferentes ecossistemas naturais afetados pela mineração, é uma relação conjunta entre a resposta do habitat e a biota. O objetivo deste estudo foi realizar uma revisão para identificar o número de publicações; quais países estão publicando mais; quais técnicas de recuperação; e grupo taxonômico são mais usados nas áreas de mineração e que contribuíram para a manutenção ou recuperação do meio ambiente. Revisamos a literatura sobre recuperação em áreas de mineração em todo o mundo, entre 1994 e 2016, usando o banco de dados on-line da Web of Science. Foram identificadas 9.000 publicações; após os procedimentos de seleção, foram analisados 467 manuscritos restantes. Desses, 34,26% foram publicados entre 1994 e 2004 e 65,74% entre 2006 e 2016. Os países que mais contribuíram foram os EUA com 16,45%, a Austrália com 13,56% e a China com 8,66%. O Brasil contribuiu com 6,9% das publicações. As técnicas de recuperação com vegetação foram as mais relatadas na literatura e as mais utilizadas. O grupo taxonômico de plantas terrestres foi o mais citado e mais utilizado na recuperação de áreas degradadas. Descobrimos que várias técnicas para recuperar áreas degradadas podem ser estabelecidas, mas a maioria não mostrou monitoramento adequado e, sem isso, os processos de recuperação podem não atingir seus objetivos e estudos que testam os tamanhos de efeitos dessas técnicas ainda são necessários

Rewilding in Southeast Asia: Singapore as a case study

Re-establishing extirpated wildlife—or “rewilding”—is touted as a way to restore biodiversity and ecosystem processes, but we lack real-world examples of this process, particularly in Southeast Asia. Here, we use a decade of aggregated camera trap data, N-mixture occupancy models, and input from local wildlife experts to describe the unassisted recolonization of two native large herbivores in Singapore. Sambar deer (Rusa unicolor) escaped from captivity (in private or public zoos) in the 1970s and contemporary camera trap data show they have only colonized nearby forest fragments and their abundance remains low. Wild pigs (Sus scrofa), in contrast, naturally recolonized by swimming from Malaysia in the 1990s and have rapidly expanded their range and abundance across Singapore. While wild pigs have not recolonized all viable green spaces yet, their trajectory indicates they soon will. We also note that a third ungulate, the muntjac deer (Muntiacus muntjak), was captured in camera trapping in 2014 and 2015 but was never recorded afterward despite increased sampling effort, and thus we do not focus on their presumably unsuccessful recolonization. The divergent rewilding trajectories between sambar deer and wild pigs suggest different conservation outcomes and management requirements. Sambar deer may restore lost plant–animal interactions such as herbivory and seed dispersal without requiring significant management. Wild pigs, in contrast, have reached high numbers rapidly and may require active management to avoid hyperabundance and negative ecological impacts in regions, such as Singapore that lack both hunting and large predators.Nanyang Technological UniversityNational Parks BoardPublished versionThe research was funded by the National Parks Board of Singapore, the Smithsonian Institution's ForestGEO program, Nanyang Technological University, and the University of Queensland (UQ)