Changes

The Northwest Bornean orangutan (''Pongo pygmaeus pygmaeus''), one of the three Bornean orangutan subspecies, has the smallest geographic range (Wich et al. 2008, Wich et al. 2012). Northwest Bornean orangutans inhabit West Kalimantan (Indonesia) from north of the Kapuas River to the eastern region of Sarawak (Malaysia). Key populations are concentrated in the following protected areas: the [[Batang Ai National Park]] and the [[Batang Ai-Lanjak-Entimau (BALE) landscape]] in Sarawak; and the Betung Kerihun and Danau Sentarum National Parks in West Kalimantan (Wich et al. 2008). Additionally, two smaller populations located in the Ulu Sebuyau National Park and Sedilu National Park in Sarawak were officially designated as protected areas in 2010 (Ancrenaz et al. 2016).

The Northwest Bornean orangutan (''Pongo pygmaeus pygmaeus''), one of the three Bornean orangutan subspecies, has the smallest geographic range (Wich et al. 2008, Wich et al. 2012). Northwest Bornean orangutans inhabit West Kalimantan (Indonesia) from north of the Kapuas River to the eastern region of Sarawak (Malaysia). Key populations are concentrated in the following protected areas: the [[Batang Ai National Park]] and the [[Batang Ai-Lanjak-Entimau (BALE) landscape]] in Sarawak; and the Betung Kerihun and Danau Sentarum National Parks in West Kalimantan (Wich et al. 2008). Additionally, two smaller populations located in the Ulu Sebuyau National Park and Sedilu National Park in Sarawak were officially designated as protected areas in 2010 (Ancrenaz et al. 2016).

It has been estimated that there are fewer than 10,000 individuals remaining in Sarawak and West Kalimantan (Wich et al. 2008). Northwest Bornean orangutans are classified as Critically Endangered on the IUCN Red List of Threatened Species (Ancrenaz et al. 2016). Encounter rates for this subspecies have decreased six-fold over the past 150 years, even in forested areas, suggesting that factors like hunting are driving population declines (Meijaard et al. 2010). The subspecies is declining rapidly, with climate and land-use changes expected to further accelerate habitat losses (Struebig et al. 2015).  

It has been estimated that there are fewer than 10,000 individuals remaining in Sarawak and West Kalimantan (Wich et al. 2008). Northwest Bornean orangutans are classified as Critically Endangered on the IUCN Red List of Threatened Species (Ancrenaz et al. 2016). Encounter rates for this subspecies have decreased six-fold over the past 150 years, even in forested areas, suggesting that factors like hunting are driving population declines (Meijaard et al. 2010). The subspecies is declining rapidly, with climate and land-use changes expected to further accelerate habitat losses (Struebig et al. 2015).