Floods in Indonesia Threaten World’s Rarest Ape: Tapanuli Orangutans

Why in News

• Media reports indicate that 33 to 54 critically endangered Tapanuli orangutans are feared killed following severe floods and landslides in North Sumatra province, Indonesia, after over 1,000 mm of rainfall in just four days.

Cause of the Disaster

• The extreme weather event followed Cyclone Senyar, which struck Sumatra on 25 November.
• Heavy rains triggered widespread landslides in the mountainous forests of Batang Toru.

Impact on Tapanuli Orangutans

• Conservation workers report that the world’s rarest ape has not been seen or heard in affected forest areas since the cyclone.
• The loss of even a few individuals is considered catastrophic, given the species’ extremely small population.

About Tapanuli Orangutan (Pongo tapanuliensis)

• Conservation status: Critically Endangered (IUCN).
• Discovery: Identified as a distinct species in 2017.
• Habitat: Mountainous forests of Batang Toru, North Sumatra.
• World’s rarest great ape.

Other Orangutan Species

• Bornean orangutan (Pongo pygmaeus)
• Sumatran orangutan (Pongo abelii)

Physical and Biological Traits

• Similar in size to other orangutan species.
• Lifespan: Up to 60 years in the wild.
• Sexual dimorphism:
  • Males significantly larger than females.
• Arboreal: Spend most of their lives in trees.

Unique Behaviour and Diet

• Exhibit distinct dietary habits not seen in other orangutans.
• Only orangutan species known to eat:
  • Certain caterpillars
  • Pinecones

Significance

• Highlights the growing threat of climate-change-driven extreme weather to biodiversity.
• Underscores the vulnerability of small, fragmented populations to natural disasters.

Sources: BBC & Others