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The future of biodiversity in Asia is increasingly dependent on networks of effective protected areas. Three wildlife sanctuaries of the Bangladesh Sundarbans are typical examples of protected areas where detection and monitoring of threats is difficult due to low densities of patrol staff and low frequency of patrolling relative to the area that requires monitoring. The aim of this study was to use camera traps to quantify: 1) the levels of different types of illegal human activities (IHA), 2) spatio-temporal variation in illegal human activities, and 3) what proportion of camera trap records can be used to identify perpetrators. Each photograph was categorized as either illegal human activity (IHA) or legal human activity (LHA) based on interpretation of the particular human activity and equipment observed in photograph. For IHA, infraction type was based on the Bangladesh Wildlife (Conservation and Security) Act 2012. A total of 914 unique human activity events were recorded (872 IHA and 42 LHA) in camera trap photos over a total of 1039 trap nights. The best model suggests that during spring tide 91% of camera trapped locations in the West Sanctuary had IHA occurring in them during the survey period, while 84% and 74% locations had IHA in the South Sanctuary and East Sanctuary respectively. Camera trapping in remote areas can potentially help protected area managers to increase rates of detection of IHA in their conservation landscapes and increase rates of arrests and prosecutions by providing appropriate supporting evidence.

Background Edge effects cause changes in bird community richness, abundance, and/or distribution within a landscape, but the avian guilds most influenced can vary among regions. Although Southeast Asia has the highest rates of deforestation and projected species loss, and is currently undergoing an explosive growth in road infrastructure, there have been few studies of the effects of forest edges on avian communities in this region. Methods We examined avian community structure in a dry evergreen forest in northeastern Thailand adjacent to a five-lane highway. We evaluated the richness and abundance of birds in 11 guilds at 24 survey points on three parallel transects perpendicular to the edge. At each point, 10-min surveys were conducted during February‒August 2014 and March‒August 2015. Vegetation measurements were conducted at 16 of the bird survey points and ambient noise was measured at all 24 survey points. Results We found a strongly negative response to the forest edge for bark-gleaning, sallying, terrestrial, and understory insectivores and a weakly negative response for arboreal frugivore-insectivores, foliage gleaning insectivores, and raptors. Densities of trees and the percentage canopy cover were higher in the interior, and the ambient noise was lower. In contrast, arboreal nectarivore-insectivores responded positively to the forest edge, where there was a higher vegetation cover in the ground layer, a lower tree density, and a higher level of ambient noise. Conclusion Planners should avoid road development in forests of high conservation value to reduce impacts on biodiversity. Where avoidance is impossible, a number of potential mitigation methods are available, but more detailed assessments of these are needed before they are applied in this region.

The loss and fragmentation of substantial areas of forest habitat, in combination with rampant hunting, has pushed many of Southeast Asia’s megafauna species to the verge of extinction. However, the extent of these declines is rarely quantified, thereby weakening lessons learned and species-based management. This need not be the case as a proliferation of camera trap surveys for large-bodied mammals across Southeast Asia, which use a standardized sampling technique, presents a rich yet under-utilized wildlife data set. Furthermore, advances in statistical techniques for assessing species distribution provide new opportunities for conducting comparative regional analyses. Here, we focus on one of Southeast Asia’s least known species of megafauna, the Endangered Asian tapir ( Tapirus indicus ), to investigate the performance of a camera trap-based spatial modeling approach in conducting a range-wide species assessment. Detection data were collectively collated from 52,904 trap days and 1,128 camera traps located across 19 study areas drawn from the Asian tapir’s entire range. Considerable variation in tapir occurrence was found between study areas in: Malaysia (0.52–0.77); Sumatra, Indonesia (0.12–0.90); Thailand (0.00–0.65); and, Myanmar (0.00–0.26), with generally good levels of estimate precision. Although tapirs were widespread (recorded in 17 of the 19 study areas), their occurrence was significantly and negatively correlated with human disturbance. Thus, this study extends the previously known applicability of camera traps to include a threatened and cryptic species by identifying where and how tapirs persist (including new records of occurrence), where future surveys should be conducted and providing a benchmark for measuring future conservation management efforts.

The Sundarbans Forest (∼10,000 km2) represents the only mangrove ecosystem inhabited by tigers Panthera tigris. However, in the Bangladesh portion of the Sundarbans (∼6,000 km2) tigers appear to have declined. The aim of this study was to examine the influence of a range of environmental and landscape variables in possible changes in the relative abundance of tigers in the Bangladesh Sundarbans over a five-year period (2007–2011). In 2007, 2011 tiger relative abundance was assessed using sign surveys. Using regression models we investigated changes in relative abundance versus multiple landscape variables (human disturbance associated with villages and commercial shipping lanes, distance to the international border with India where there is enhanced patrolling, presence of forest guard stations, number of criminal prosecutions and forest protection status). Tiger relative abundance was higher in 2007 and declined by 2011 with changes best explained by the proximity to international boundaries. This result might have been affected by the high levels of security patrols at the India-Bangladesh border along with cross border tiger movement between India and Bangladesh. Neighboring tiger range countries could strengthen cross-border law enforcement, increasing protection of dispersing animals. Particularly alarming was the absence of a positive effect of protected areas relative to those outside the protected area system or forest guard stations, implying a lack of management effectiveness suggesting an urgent need for an improved strategy for managing tigers and their habitats. Keywords: Wildlife poaching, Population declines, Transboundary protection, Joint patrolling, Protected area effectiveness

Fragmentation of tropical forests has wide-ranging effects on wildlife communities, but the actual mechanisms of species impoverishment remain poorly understood. Small mammal assemblages on recent land-bridge islands at Chiew Larn, Thailand, were compared with nearby continuous forest from the fifth to seventh years following island creation. Assemblages on islands rapidly developed a nested structure, converging in composition and representing a depauperate subset of those in continuous forest. Among species that persisted on islands, many had altered abundances, with some increasing and others declining. A “random placement model” accounted for the observed distributions of species on mainland sites but not on islands, suggesting that nested island assemblages were generated both by changes in species distributions and abundances after fragmentation. Six species were prone to extinction on islands, whereas three increased in abundance, apparently because they were good over-water colonizers or favored disturbed habitats on islands. We conclude that the development of nested mammal assemblages in the Chiew Larn archipelago was caused both by differential vulnerabilities of species to local extinction and by varying abilities of species to colonize islands and to thrive in disturbed island habitats.