Using interview surveys and multispecies occupancy models to inform vertebrate conservation.

Species distribution data are an essential biodiversity variable requiring robust monitoring to inform wildlife conservation. Yet, such data remain inherently sparse because of the logistical challenges of monitoring biodiversity across broad geographic extents. Surveys of people knowledgeable about the occurrence of wildlife provide an opportunity to evaluate species distributions and the ecology of wildlife communities across large spatial scales. We analyzed detection histories of 30 vertebrate species across the Western Ghats biodiversity hotspot in India, obtained from a large-scale interview survey of 2318 people who live and work in the forests of this region. We developed a multispecies occupancy model that simultaneously corrected for false-negative (non-detection) and false-positive (misidentification) errors that interview surveys can be prone to. Using this model, we integrated data across species in composite analyses of the responses of functional species groups (based on disturbance tolerance, diet, and body mass traits) to spatial variation in environmental variables, protection, and anthropogenic pressures. We observed a positive association between forest cover and the occurrence of species with low tolerance of human disturbance. Protected areas were associated with higher occurrence for species across different functional groups compared with unprotected lands. We also observed the occurrence of species with low disturbance tolerance, herbivores, and large-bodied species was negatively associated with developmental pressures, such as human settlements, energy production and mining, and demographic pressures, such as biological resource extraction. For the conservation of threatened vertebrates, our work underscores the importance of maintaining forest cover and reducing deforestation within and outside protected areas, respectively. In addition, mitigating a suite of pervasive human pressures is also crucial for wildlife conservation in one of the world's most densely populated biodiversity hotspots.

Uso de Encuestas y Modelos de Ocupación Multiespecies para Orientar la Conservación de Vertebrados Resumen Los datos de distribución de especies son una variable esencial de la biodiversidad que requieren de un monitoreo sólido para orientar la conservación de la fauna. Aun así, dichos datos permanecen inherentemente escasos debido a los obstáculos logísticos del monitoreo de la biodiversidad a lo largo de extensiones geográficas generalizadas. Las encuestas realizadas a personas conocedoras de la incidencia de fauna proporcionan una oportunidad para evaluar la distribución de las especies y la ecología de las comunidades de fauna en escalas espaciales grandes. Analizamos las historias de detección de 30 especies de vertebrados en los Ghats Occidentales de la India obtenidos a partir de una encuesta a gran escala realizada por entrevistas a 2318 personas que viven y trabajan en los bosques de esta región. Desarrollamos un modelo de ocupación multiespecies que corrigió simultáneamente los errores falsos negativos (no detección) y los falsos positivos (identificación correcta) a los que están propensos las encuestas por entrevista. Con este modelo, integramos los datos de todas las especies a un análisis compuesto de las respuestas de los grupos funcionales de especies (con base en la tolerancia a la perturbación, dieta y características de masa corporal) para la variación espacial en las variables ambientales, protección y presiones antropogénicas. Observamos una asociación positiva entre la incidencia de especies con la baja tolerancia a la perturbación humana y a la cobertura forestal. Las áreas protegidas estuvieron asociadas con una incidencia mayor para las especies ubicadas en diferentes grupos funcionales comparadas con las áreas desprotegidas. También observamos que la incidencia de especies con una tolerancia baja a las perturbaciones, herbívoros y especies de mayor tamaño estaba asociada negativamente con las presiones de desarrollo, como los asentamientos humanos, la producción de energías y minería, y las presiones demográficas, como la extracción de recursos biológicos. Para la conservación de vertebrados amenazados, nuestro trabajo hace hincapié en la importancia de mantener la cobertura forestal y reducir la deforestación dentro y fuera de las áreas protegidas, respectivamente. Además, la mitigación de un conjunto de presiones humanas dominantes también es crucial para la conservación de la naturaleza en uno de los puntos calientes de biodiversidad con una de las mayores densidades poblacionales del mundo.

Local and landscape correlates of primate distribution and persistence in the remnant lowland rainforests of the Upper Brahmaputra Valley, northeastern India.

Habitat fragmentation affects species distribution and abundance, and drives extinctions. Escalated tropical deforestation and fragmentation have confined many species populations to habitat remnants. How worthwhile is it to invest scarce resources in conserving habitat remnants within densely settled production landscapes? Are these fragments fated to lose species anyway? If not, do other ecological, anthropogenic, and species-related factors mitigate the effect of fragmentation and offer conservation opportunities? We evaluated, using generalized linear models in an information-theoretic framework, the effect of local- and landscape-scale factors on the richness, abundance, distribution, and local extinction of 6 primate species in 42 lowland tropical rainforest fragments of the Upper Brahmaputra Valley, northeastern India. On average, the forest fragments lost at least one species in the last 30 years but retained half their original species complement. Species richness declined as proportion of habitat lost increased but was not significantly affected by fragment size and isolation. The occurrence of western hoolock gibbon (Hoolock hoolock) and capped langur (Trachypithecus pileatus) in fragments was inversely related to their isolation and loss of habitat, respectively. Fragment area determined stump-tailed (Macaca arctoides) and northern pig-tailed macaque occurrence (Macaca leonina). Assamese macaque (Macaca assamensis) distribution was affected negatively by illegal tree felling, and rhesus macaque (Macaca mulatta) abundance increased as habitat heterogeneity increased. Primate extinction in a fragment was primarily governed by the extent of divergence in its food tree species richness from that in contiguous forests. We suggest the conservation value of these fragments is high because collectively they retained the entire original species pool and individually retained half of it, even a century after fragmentation. Given the extensive habitat and species loss, however, these fragments urgently require protection and active ecological restoration to sustain this rich primate assemblage.

Local hunting and the conservation of large mammals in India.

Hunting by local communities is among the most widespread threats to Indian wildlife, yet, the understanding of its nature, extent, and impacts on wildlife has been poor. We surveyed 2 protected areas--Kudremukha and Nagara-holé--in southern India to assess the impacts of local hunting on large mammals. Detailed interviews with retired and active hunters were employed to describe hunting patterns. Impacts of hunting were assessed by comparing large-mammal abundance in adjacent sites differing in their vulnerability to hunting. In Kudremukha, at least 26 species of mammals were hunted, mostly with guns, at an estimated intensity of 216 hunter-days per month per village. In Nagaraholé, 6 of the 9 focal species of large mammals occurred at significantly lower densities at the heavily hunted site where enforcement capabilities were poorer. Our data underscore the importance of preservationist programs in the conservation of large mammals in a context of extensive local hunting.

Living amidst large wildlife: livestock and crop depredation by large mammals in the interior villages of Bhadra Tiger Reserve, South India.

Conflict with humans over livestock and crops seriously undermines the conservation prospects of India's large and potentially dangerous mammals such as the tiger (Panthera tigris) and elephant (Elephas maximus). This study, carried out in Bhadra Tiger Reserve in south India, estimates the extent of material and monetary loss incurred by resident villagers between 1996 and 1999 in conflicts with large felines and elephants, describes the spatiotemporal patterns of animal damage, and evaluates the success of compensation schemes that have formed the mainstay of loss-alleviation measures. Annually each household lost an estimated 12% (0.9 head) of their total holding to large felines, and approximately 11% of their annual grain production (0.82 tonnes per family) to elephants. Compensations awarded offset only 5% of the livestock loss and 14% of crop losses and were accompanied by protracted delays in the processing of claims. Although the compensation scheme has largely failed to achieve its objective of alleviating loss, its implementation requires urgent improvement if reprisal against large wild mammals is to be minimized. Furthermore, innovative schemes of livestock and crop insurance need to be tested as alternatives to compensations.