Studi Awal Karakteristik Pohon Sarang Dan Sarang Orangutan (Pongo pygmaeus pygmaeus : Linnaeus 1760)

Pongo pygmaeus pygmaeus constitutes one of Borneo orangutan subspecies. Orangutans are arboreal animals that utilitize twigs and branches to build a nest. Scientific informations related to subspecies P. p. pygmaeus are considered remarkably rare. The aim of this study was to determine the characteristics of P. p. pygmaeus nesting tree and nest. This study was conducted from April to July 2013, at Peninjau Hill, Kapuas Hulu. Data collection method used in this study was line transect method. The parameters observed were the height of nesting tree, nest height, nest position, nest class and the type of nesting tree. The nesting tree height of  P. p. pygmaeus in Peninjau Hill ranged from 5 m to 39 m with the nest hight ranged from     3 m – 37 m. Generally, the position of nest is at position 2 with nest class mostly in class 4. The nest height significantly corresponds to tree height. Nesting trees consist of 42 trees genera dominated by Santiria. Trees of Dipterocarpaceae family dominate as the nesting tree of orangutan in Peninjau Hill. As much as 46,53% of nesting tree of P. p. pygmaeus also serves as feeding tree

Quantifying Killing of Orangutans and Human-Orangutan Conflict in Kalimantan, Indonesia

Human-orangutan conflict and hunting are thought to pose a serious threat to orangutan existence in Kalimantan, the Indonesian part of Borneo. No data existed prior to the present study to substantiate these threats. We investigated the rates, spatial distribution and causes of conflict and hunting through an interview-based survey in the orangutan's range in Kalimantan, Indonesia. Between April 2008 and September 2009, we interviewed 6983 respondents in 687 villages to obtain socio-economic information, assess knowledge of local wildlife in general and orangutan encounters specifically, and to query respondents about their knowledge on orangutan conflicts and killing, and relevant laws. This survey revealed estimated killing rates of between 750 and 1800 animals killed in the last year, and between 1950 and 3100 animals killed per year on average within the lifetime of the survey respondents. These killing rates are higher than previously thought and are high enough to pose a serious threat to the continued existence of orangutans in Kalimantan. Importantly, the study contributes to our understanding of the spatial variation in threats, and the underlying causes of those threats, which can be used to facilitate the development of targeted conservation management

Why Don't We Ask? A Complementary Method for Assessing the Status of Great Apes

Species conservation is difficult. Threats to species are typically high and immediate. Effective solutions for counteracting these threats, however, require synthesis of high quality evidence, appropriately targeted activities, typically costly implementation, and rapid re-evaluation and adaptation. Conservation management can be ineffective if there is insufficient understanding of the complex ecological, political, socio-cultural, and economic factors that underlie conservation threats. When information about these factors is incomplete, conservation managers may be unaware of the most urgent threats or unable to envision all consequences of potential management strategies. Conservation research aims to address the gap between what is known and what knowledge is needed for effective conservation. Such research, however, generally addresses a subset of the factors that underlie conservation threats, producing a limited, simplistic, and often biased view of complex, real world situations. A combination of approaches is required to provide the complete picture necessary to engage in effective conservation. Orangutan conservation (Pongo spp.) offers an example: standard conservation assessments employ survey methods that focus on ecological variables, but do not usually address the socio-cultural factors that underlie threats. Here, we evaluate a complementary survey method based on interviews of nearly 7,000 people in 687 villages in Kalimantan, Indonesia. We address areas of potential methodological weakness in such surveys, including sampling and questionnaire design, respondent biases, statistical analyses, and sensitivity of resultant inferences. We show that interview-based surveys can provide cost-effective and statistically robust methods to better understand poorly known populations of species that are relatively easily identified by local people. Such surveys provide reasonably reliable estimates of relative presence and relative encounter rates of such species, as well as quantifying the main factors that threaten them. We recommend more extensive use of carefully designed and implemented interview surveys, in conjunction with more traditional field methods

Mapping perceptions of species' threats and population trends to inform conservation efforts: the Bornean orangutan case study

AIM: We demonstrate a robust approach for predicting and mapping threats and population trends of wildlife species, invaluable for understanding where to target conservation resources. We used the endangered Bornean orangutan (Pongo pygmaeus) as our case study to facilitate and strengthen conservation efforts by the Indonesian government to stabilize populations by 2017. LOCATION: Kalimantan, Indonesian Borneo. METHODS: Local knowledge of threats to orangutan populations was gathered through questionnaire interviews in 531 villages (512 in Kalimantan) within known orangutan range. These data were integrated with 39 environmental/socio-economic spatial variables using boosted regression tree modelling to predict threat levels and population trends across Kalimantan and to identify key combinations of threats and trends that can help to direct appropriate conservation actions. RESULTS: Nineteen percentage of villages surveyed in Kalimantan reported human-orangutan conflicts. High-predicted conflict likelihood was extensive, strongly associated with road density (very low or high) and temperature seasonality. Recent orangutan killings were reported in 23% of villages. High killing risk was highly associated with greater surrounding orangutan habitat and for villages more than 60 km from oil palm plantations. Killings by respondents were reported in 20% of villages with higher likelihoods associated with greater range in rainfall and temperature, and higher proportion of Christian believers. Orangutan populations were predicted to decline/become locally extinct across the majority of their range in Kalimantan over the next decade, with few regions predicted to support stable populations. MAIN CONCLUSIONS: Human-orangutan conflicts and killings occur extensively in Kalimantan, with many populations at risk of decline or localized extinctions. Effective conservation actions are therefore urgently needed. Our approach better informs conservation managers in understanding the extent, spatial patterns and drivers of threats to endangered species such as the orangutan. This is essential to better design management strategies that can minimize or avert the species' decline

Global demand for natural resources eliminated more than 100,000 Bornean orangutans

Unsustainable exploitation of natural resources is increasingly affecting the highly biodiverse tropics. Although rapid developments in remote sensing technology have permitted more precise estimates of land-cover change over large spatial scales, our knowledge about the effects of these changes on wildlife is much more sparse. Here we use field survey data, predictive density distribution modeling, and remote sensing to investigate the impact of resource use and land-use changes on the density distribution of Bornean orangutans (Pongo pygmaeus). Our models indicate that between 1999 and 2015, half of the orangutan population was affected by logging, deforestation, or industrialized plantations. Although land clearance caused the most dramatic rates of decline, it accounted for only a small proportion of the total loss. A much larger number of orangutans were lost in selectively logged and primary forests, where rates of decline were less precipitous, but where far more orangutans are found. This suggests that further drivers, independent of land-use change, contribute to orangutan loss. This finding is consistent with studies reporting hunting as a major cause in orangutan decline. Our predictions of orangutan abundance loss across Borneo suggest that the population decreased by more than 100,000 individuals, corroborating recent estimates of decline. Practical solutions to prevent future orangutan decline can only be realized by addressing its complex causes in a holistic manner across political and societal sectors, such as in land-use planning, resource exploitation, infrastructure development, and education, and by increasing long-term sustainability

Effectiveness of 20 years of conservation investments in protecting orangutans

Conservation strategies are rarely systematically evaluated, which reduces transparency, hinders the cost-effective deployment of resources, and hides what works best in different contexts. Using data on the iconic and critically endangered orangutan (Pongo spp.), we developed a novel spatiotemporal framework for evaluating conservation investments. We show that around USD 1 billion was invested between 2000 and 2019 into orangutan conservation by governments, non-governmental organizations, companies and communities. Broken down by allocation to different conservation strategies, we find that habitat protection, patrolling and public outreach had the greatest return-on-investment for maintaining orangutan populations. Given variability in threats, land-use opportunity costs, and baseline remunerations in different regions, there were differential benefits-per-dollar invested across conservation activities and regions. We show that, while challenging from a data and analysis perspective, it is possible to fully understand the relationships between conservation investments and outcomes, and the external factors that influence these outcomes. Such analyses can provide improved guidance towards more effective biodiversity conservation. Insights into the spatiotemporal interplays between the costs and benefits driving effectiveness can inform decisions about the most suitable orangutan conservation strategies for halting population declines. While our study focuses on the three extant orangutan species of Sumatra and Borneo, our findings have broad application for evidence-based conservation science and practice worldwide

Crop raiding intensity in different villages across Kalimantan.

<p>High  =  reported conflict frequency every week; Medium  =  every month; Low  =  once a year or less frequently.</p

Potential distribution area of orangutan in Central Kalimantan (yellow), West Kalimantan (purple) and East Kalimantan (green), and the village area boundaries within these regions.

<p>Potential distribution area of orangutan in Central Kalimantan (yellow), West Kalimantan (purple) and East Kalimantan (green), and the village area boundaries within these regions.</p