BackgroundThe degree to which loud-calls in nonhuman primates can be used as a reliable taxonomic tool is the subject of ongoing debate. A recent study on crested gibbons showed that these species can be well distinguished by their songs; even at the population level the authors found reliable differences. Although there are some further studies on geographic and phylogenetic differences in loud-calls of nonhuman primate species, it is unclear to what extent loud-calls of other species have a similar close relation between acoustic structure, phylogenetic relatedness and geographic distance. We therefore conducted a field survey in 19 locations on Sumatra, Java and the Mentawai islands to record male loud-calls of wild surilis (Presbytis), a genus of Asian leaf monkeys (Colobinae) with disputed taxanomy, and compared the structure of their loud-calls with a molecular genetic analysis.ResultsThe acoustic analysis of 100 surili male loud-calls from 68 wild animals confirms the differentiation of P.potenziani, P.comata, P.thomasi and P.melalophos. In a more detailed acoustic analysis of subspecies of P.melalophos, a further separation of the southern P.m.mitrata confirms the proposed paraphyly of this group. In concordance with their geographic distribution we found the highest correlation between call structure and genetic similarity, and lesser significant correlations between call structure and geographic distance, and genetic similarity and geographic distance.ConclusionsIn this study we show, that as in crested gibbons, the acoustic structure of surili loud-calls is a reliable tool to distinguish between species and to verify phylogenetic relatedness and migration backgrounds of respective taxa. Since vocal production in other nonhuman primates show similar constraints, it is likely that an acoustic analysis of call structure can help to clarify taxonomic and phylogenetic relationships.

Abstract. Rahman DE, Rinaldi D, Kuswanda W, Siregar R, Noor CF, Hakim F, Arief H, Putro HR. 2019. Determining the landscape priority and their threats for the Critically Endangered Pongo tapanuliensis population in Indonesia. Biodiversitas 20: 3584-3592. Understanding the habitat preference and spatial distribution for the management of medium-large primates is important for conserving and enhancing biodiversity in the most isolated and remote Batang Toru landscape, North Sumatra, Indonesia. Based on the first extensive orangutan survey dataset during 2000 and 2007, we aimed to provide microhabitat preference and distribution assessment for the new species of orangutan (Pongo tapanuliensis), a poorly known and threatened primate endemic in Indonesia. To inform future conservation measures, we develop a predictive habitat suitability map and use this map to show the current threat for Tapanuli orangutan in their habitat and as the basis of proposed of the landscape boundary in Batang Toru ecosystem. In order to identify some environmental factors affecting conservation, we analyzed the microhabitat preference of Tapanuli orangutan using maximum entropy modeling (MaxEnt). The modeled orangutan distribution map covers 1.458,06 km2 (58,52% of Batang Toru’s landscape) and reveals three distinct distribution areas. The four most important environmental predictors are the distance from the cultivation area, NDVI, mean precipitation, and distance from the secondary forest edge. The distribution of the orangutan overlap with land-use categories reveals that 42,98% of the distribution lies in protected areas, but that 15,54% lies in natural forest concessions and area for other purposes (APL). Large scale land-use masterplan is needed to provide strategies and control for future development in the possibility of land uses and management are allowed in the landscape including its conservation policies. Moreover, collaborative management strategies are needed to develop a sustainable management system. We confirmed the Batang Toru landscape as the sole of Indonesia’s biodiversity hotspots and a critical area to preserve the Tapanuli orangutan.

The objective of this study is to reveal birds found in Greater Jakarta Area, and categorize the bird based on the probability of encounter, namely urban exploiters, adapters, and avoiders. Bird list of 36 sites in Greater Jakarta Area collected by other workers in the last seven years were used as the basis of determination. Percentiles were used as cut off points for each category. Of the 243 bird species found the study area, there were 8 species categorized as urban exploiters and the 3 highest ranks were the Sooty-headed Bulbul, Cave Swiftlets and Eurasian Tree Sparrow. Forty-nine bird species were categorized as urban adapters. The rest of species, which constitute a big portion of the species spotted in the Greater Jakarta (186 species, 76.5%) were categorized into urban avoiders. The nocturnal species was represented only by Black-crowned Night-heron. The presence of species exploiters and adapters showed that (a) Greater Jakarta Area still have sufficient green open spaces, including significant numbers of mature and decayed trees; (b) there were still good quality of small rivers, creeks, and swampy area; (c) small mammals were sufficient to support small raptors, and (d) bird community was quite rich to perform brood parasitism habit.

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The Javan leopard is an apex predator whose distribution is limited to the island of Java and Nusakambangan Island, and it is classified as an endangered species. The forest habitat of the Javan leopard is subject to annual damage, which causes a decrease in its quality and suitability as a habitat for this species. This study aimed to determine the changes in the suitability of the Javan leopard habitat from 2000 to 2020 and the variables affecting it. A habitat suitability analysis was performed using the MaxEnt application. The data included coordinate points and environment variables. The variables included the distance from rivers, undisturbed tropical forests, degraded forests, permanent water, shrubs, farms, plantations, and settlements. The model produced an AUC value of 0.812, indicating the model was good. In the 2000 model year, the highly suitable habitat area of the Javan leopard was 2481.38 km2, the suitable habitat area was 2630.763 km2, and the unsuitable area was 7790.155 km2. In the 2020 model, the area of highly suitable habitat was 1429.647 km2, the area of suitable habitat was 2379.344 km2, and the area that was not suitable was 9093.081 km2. Primary forest was the variable that contributed most to the model.

Javan gibbon (Hylobates moloch) is one of endemic primates in Java Island, which listed as endangered and facing the high risk of extinction. Conservation efforts need to be taken immediately in regard to the decrease of this species population. One of aspects that support conservation effort is data on daily activity of this species. The aim of this study was to determine the daily activities of Javan gibbon juvenile at Citalahab Forest Gunung Halimun Salak National Park. We used focal sampling method to collect behavioral data and recording the activity of each individual Javan gibbon by continuous recording. Average time the daily activities of the three groups is 9 hours 56 minutes. Percentage of daily activity from the highest to the lowest is the resting (36.21%), feeding (33.33%), moving (23.05%), socializing (4.94%) and undetected (2.47%). Mostly social activities that do by javan gibbon is play with most frequently performed is wrestling. Javan gibbon in Cikaniki – Citalahab used 11 species as food resource. There are four types of trees used as sleeping tree over the research. The dominant tree strata for sleeping tree is strata A (over 30 m).