Proboscis Monkey the Natural Swimmers

Proboscis monkey might be best known for their giant, bulbous noses, but scientists are sniffing out another of these monkey’s unique attributes: their swimming abilities.

To discover more about these water-loving primates, conservation biologist Amalia Rezeki recently spent a few weeks on Indonesian Borneo’s Bakut island filming the animal and their behavior in mangrove forests. (read about swimming pings and other surprising animals that love water).

“The main primates in the area that people think of are orangutans. We thought that a video about these monkey’ swimming abilities would help bring some positive attentions.” Says Rezeki. Who works with Sahabat bekantan Indonesia, a nonprofit that works to protect proboscis monkey, also called bekantan.

Due to loss of their mangrove habitat and hunting, proboscis monkey are listed as endangered, with fewer 7.000 animal left in the wild.

Rezeki’s expedition discovered several monkeys on the island, suggesting the species is still hanging on.

Natural Swimmers

Proboscis monkey likely took to the water becaouse ”it’s hard to live in a swamp without being able to swim.” Says Lee Harding, chief scientist at SciWrite Environmental Sciences and an expert in proboscis monkey (read more about mangroves, forest the tide, in National Geographic magazine).

For these primates, swimming serves a practical function: to get food. The animal have to travel fat and wide to find the young, tender leaves that make up the bulk of their diet-and swimming gets the job done faster.

Propelled by partially webbed fingers and toes, the monkeys can even swim underwater-although no one knows exactly how long they can hold their breath, according to Liz Bennett, vice precident of species conervation an the Wlidlife Conservation Society in New York city. (read more about the monkey with the outlandish nose).

“The extent that they swimm is quite unusual, especially since its close relative don’t swim,” she adds.

Monkey Business

Harding, who wasn’t involved in the recent expedition, has long been fascianated by the species, which live in harems with one territorial male and around eight females. (see an intimate portrait of a proboscis monkey in captivity).

On this first visit to Borneo with his brother several decades ago, they found out the hard way how males mark their territory and intimidate those who encroach on their land.

“This big male, he was in a tree by the river, and he just started urinating on my brother,” Harding says.

But swimming isn’t fun and games for proboscis monkeys. Traveling by water is risky: Crocodiles, phyton, and monitor lizards often prey on the swimming primates.

Vanishing Forest

Another danger to the species is Borneo’s disappearing mangroves. Between one-third and one-half of these forest have already disappeared due to timber harvesting and drainage for oil palm plantation, according to the Mangrove Actions Project. (See more pictures of mangroves from around the world).

More and more of Borneo’s growing population is moving to the same lowland areas where the monkey live.

“That proximity-as well as the animals’ habit of sleeping in exposed tress –makes the animals particularly vulnurable to sport hunters,” Harding says.

Though the goverment has set aside some areas as refuges for proboscis monkeys, they’re still vulnurable to hunting.

“They’re becoming more and more threatened, and humans are their biggest threat.” Says the Wildlife Conservation Society’s Bennett. “We need to do a better job of protecting them.”

Carrie Arnold (November 11, 2016 7;00 PM)