Sunday, November 10, 2013

Pygmy Elephants: The Largest Dwarfs

By Lisa Barrett

Pygmy elephants, dwarf-like versions of elephants, were originally thought to be an entirely different species of elephant altogether. However, research confirms that there are currently only three living species of elephants: Asian elephants (Elephas maximus), Savanna elephants (Loxodonta Africana), and Forest elephants (Loxodonta cyclotis). So, how are pygmy elephants related to elephants who have earned an official species classification?

Borneo pygmy elephants in the Lower Kinabatangan Wildlife Sanctuary.
Photo © Rob Colgan

There has been much debate about the classification of the pygmy elephant. In Africa, the African pygmy elephant used to be classified as its own species, Loxodonta pumilio, but it has since been reclassified as a smaller-sized morph of the African forest elephant. On the other hand, in Asia the Borneo pygmy elephant (Elephas maximus borneensis) is considered to be a subspecies of Asian elephants, and many of them live in the Kinabatangan River Basin (map below) in northeastern Borneo.

Many Borneo pygmy elephants live in the Kinabatangan River Basin.

A study in 2003 by WWF and Columbia University upheld that the Borneo pygmy elephant separated from the Asian elephant about 300,000 years ago, even though people historically believed that the Sultan of Sulu from Java brought the elephants in 1521 to live in Borneo. The Borneo pygmy elephant is about one meter shorter than its mainland counterpart (the Asian elephant) and has a babyish face and straight tusks. Supposedly, pygmy elephants are also less aggressive than mainland Asian elephants.

Differences among African elephants, Asian elephants, and Borneo pygmy elephants.

What makes pygmy elephants different from dwarfs? Whereas pygmy elephants are a subspecies and smaller version of an Asian elephant, dwarf elephants (who were ancestors of elephant relatives) lived on isolated islands in the Pleistocene era with few predators and resources. Their relatively small environment (compared to that of mainland Asian elephants) with fewer resources selected for their bodies to become reduced in size over many generations. The inverse process of this is called gigantism, when animals—like the dodo—become larger than normal in size in response to having a lack of predators.

Regardless of their classification, the pygmy elephant is in danger of becoming extinct. This is mainly due to habitat loss and human-elephant conflict. In fact, the WWF estimates that there are fewer than 1,500 wild Borneo pygmy elephants. In addition, fourteen pygmy elephants were mysteriously poisoned in January 2013. Pygmy elephants also suffer from habitat loss as land is cleared to make way for palm-oil plantations.

A baby pygmy elephant investigates the body of its poisoned mother.


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