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Conservation of threatened species is dependent on consistent population monitoring. We present the first status assessment of critically endangered Sumatran tigers (Panthera tigris sumatrae) and their prey in the Ulu Masen Ecosystem, Aceh, Indonesia. Our estimates of tiger habitat use are the first reported for a Sumatran ecosystem unprotected at the national level. During 6,732 trap nights accumulated over 23 months of camera-trap monitoring in 2020 and 2022, tigers were detected 39 times at 16 of the 52 stations. We identified 11 individual tigers but sex ratios were highly skewed: 8 males, 1 female, and 2 individuals of unknown sex. Cubs were not photographed either year and we did not observe evidence of tiger reproduction. Tiger habitat use (Ѱ = 0.52, SE = 0.15) was negatively influenced by human disturbance and positively influenced by elevation but those associations were not significant. Our study documents a widespread prey base but uncovers demographic characteristics of tigers indicative of heavy poaching pressures. We conclude that tiger-targeted protection is urgently needed to ensure the species' persistence in Ulu Masen which, together with the adjacent Leuser Ecosystem, represents the largest contiguous tiger conservation landscape remaining in Sumatra., (© 2024. The Author(s).)

Mangroves are uniquely important ecosystems, for preserving biodiversity, sustaining livelihoods, and mitigating against climate change. However, they are degraded globally and are therefore a priority for ecosystem restoration. To date, the assessment of mangrove restoration outcomes is generally poor, and the limited studies that do exist are focused largely on forest area. Thus, more holistic ways of assessing the outcomes of mangrove restoration projects on biodiversity and associated ecological processes are urgently needed. Ecological networks are a useful tool for simultaneously examining both. Here, we assessed the utility of using species‐interaction networks for evaluating mangrove restoration outcomes for the first time. We compared the structure and complexity of mangrove ecological networks in replicated "monoculture reforestation," "mixed species regeneration" and "reference forest" plots in two study areas in Sulawesi, Indonesia, an estuarine, and a coastal fringe mangrove system. We also combined and evaluated sampling methods, utilizing traditional plant–animal sampling while also integrating video recording data in a novel way. We found significant differences in the structure and complexity of mangrove networks between restored and natural plots, with contrasting effects between the two sites. Our results show differences in the complex ways in which taxa interact in mangrove restoration projects, which would be overlooked if common biodiversity metrics, such as species richness, were used alone, with consequences for the restoration of ecosystem functioning. We also highlight the utility of video recording data collection for constructing species‐interaction networks, overcoming the detrimental impacts of observer presence for some key species. [ABSTRACT FROM AUTHOR]

Indonesia is embarking on an ambitious relocation of its capital city to Kalimantan, Borneo, bringing with it major urban and road infrastructure. Yet, despite being one of the world's most biologically diverse regions, the potential implications of this development for wildlife have yet to be fully assessed. We explored the potential impacts of the capital relocation, and road expansion and upgrades to critical habitat for medium-large mammals (>1 kg) using camera trap data from 11 forested landscapes. We applied Bayesian multi-species occupancy models to predict community and species-level responses to anthropogenic and environmental factors. We extrapolated spatial patterns of occupancy and species diversity across the forests of Kalimantan and identified "critical habitats" as the top 20 th percentile of occupancy and species richness values. We subsequently overlapped these critical habitat layers with infrastructure impact zones to estimate the area that could potentially be affected by direct or secondary impacts. At both the community and species-level, distance to primary roads had the strongest negative influence on habitat-use. Occupancy was also influenced by forest quality and multidimensional poverty conditions in adjacent villages, demonstrating the sensitivity of biodiversity to socio-ecological pressures. Less than 1 % of the critical habitat for the threatened mammal community lay within the direct impact zone (30 km radius) of the capital relocation. However, approximately 16 % was located within 200 km and could potentially be affected by uncontrolled secondary impacts such as urban sprawl and associated regional development. The often-overlooked secondary implications of upgrading existing roads could also intersect a large amount of critical habitat for lowland species. Mitigating far-reaching secondary impacts of infrastructure development should be fully incorporated into environmental impact assessments. This will provide Indonesia with an opportunity to set an example of sustainable infrastructure development in the tropics., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Aside from anecdotal evidence, terrestriality in orangutans (Pongo spp.) has not been quantified or subject to careful study and important questions remain about the extent and contexts of terrestrial behavior. Understanding the factors that influence orangutan terrestriality also has significant implications for their conservation. Here we report on a camera trapping study of terrestrial behavior in the northeastern Bornean orangutan, Pongo pygmaeus morio, in Wehea Forest, East Kalimantan, Indonesia. We used 78 non-baited camera traps set in 43 stations along roads, trails, and at mineral licks (sepans) to document the frequency of orangutan terrestriality. Habitat assessments were used to determine how terrestrial behavior was influenced by canopy connectivity. We compared camera trapping results for P. p. morio to those for a known terrestrial primate (Macaca nemestrina), and another largely arboreal species (Presbytis rubicunda) to assess the relative frequency of terrestrial behavior by P. p. morio. A combined sampling effort of 14,446 trap days resulted in photographs of at least 15 individual orangutans, with females being the most frequently recorded age sex class (N=32) followed by flanged males (N=26 records). P. p. morio represented the second most recorded primate (N=110 total records) of seven primate species recorded. Capture scores for M. nemestrina (0.270) and P. p. morio (0.237) were similar and almost seven times higher than for the next most recorded primate, P. rubicunda (0.035). In addition, our results indicate that for orangutans, there was no clear relationship between canopy connectivity and terrestriality. Overall, our data suggest that terrestriality is relatively common for the orangutans in Wehea Forest and represents a regular strategy employed by individuals of all age-sex classes. As Borneo and Sumatra increasingly become characterized by mixed-use habitats, understanding the ecological requirements and resilience in orangutans is necessary for designing optimal conservation strategies., (© 2013 Wiley Periodicals, Inc.)