Land-cover changes predict steep declines for the Sumatran orangutan ( Pongo abelii )

Abstract

New surveys provide higher estimate of Sumatran orangutans than previously, but future scenarios indicate decline continues.

Impending extinction crisis of the world’s primates: Why primates matter

“…However, a recent study from the Udzungwa Mountains of Tanzania combined locally based monitoring routines and advanced statistical approaches to investigate population abundance, even when information was missing for some monitoring periods ( 120 ). Another study showed the value of basic field procedures (transect surveys) in monitoring Sumatran orangutan populations, with results that doubled the estimated population from 6600 to 14,613, even though the population was still assessed as declining rapidly due to deforestation ( 138 ). …”

The Tapanuli orangutan: Status, threats, and steps for improved conservation

“…Second, because of the immediate threat posed to the new species by the development of a hydrodam to generate electricity (Sloan, Supriatna, Campbell, Alamgir, & Laurance, ). As the species has only been described recently there is no paper that summarizes its status and threats even though some of that information is available from a previous study where this species was still considered a population of the Sumatran orangutan ( Pongo abelii ) (Wich et al, ). In this letter, we aim to remedy this gap by providing a succinct overview of the status of and threats to the Tapanuli orangutan, as well as by identifying key steps toward improved conservation.…”

Infrastructure development and contested forest governance threaten the Leuser Ecosystem, Indonesia

“…It would also cut the last forest corridors (notably within the WHS) connecting the eastern and western hemispheres of the Leuser. Moreover, if this highway were developed, it would bisect the Leuser and known habitat ranges of threatened tigers (Dinerstein et al, 2007), orangutans (Wich et al, 2008;Wich et al, 2011;Wich et al, 2016), elephants (Leimgruber et al, 2003), and possibly rhinoceros (unknown as range data are restricted to prevent poaching). This planned highway is additional to 99 km of roads planned within the Leuser, just north of epicentres no.…”

“…Most of the priority conservation areas are directly threatened by planned infrastructure developments. If fully realised, these developments would significantly fragment one of Asia's last remaining wildlands and the only habitat in which threatened orangutans, elephants, rhinoceros and tigers co-occur (Leimgruber et al, 2003;Wibisono et al, 2011;Wich et al, 2016). Revised conservation planning is required to prevent such an outcome.…”