Species Nasalis larvatus
Proboscis Monkey Basics
The proboscis monkey (Nasalis larvatus) is a large primate found only on Borneo’s island. It gets its name from the males’ long, drooping noses, and it spends much of its time in the trees near mangrove forests or jungle streams. It’s also known as the long-nosed monkey or the bekantan in its native Indonesia. The species’ numbers are declining as a result of deforestation in its tropical rainforest environment, and it is designated as endangered on the IUCN Red List.
Proboscis Monkey Description
Female proboscis monkeys are roughly half the size of males, weighing up to 50 lbs (22.5 kg). Their fur is light brown in hue, with reddish-brown tones towards the shoulders and head, and grey on the arms and legs. Males have a head-to-body length of around 26–30 in (66–76 cm), while females have a head-to-body length of about 21–24 in (52–62 cm). Males also have large, bulbous, and often dangling noses, which are the source of the species’ name. These velvety noses may grow up to 4 inches (10 cm) long and dangle lower than their mouths. Female monkeys, who have smaller, triangular noses, lack these. Webbed toes and fingers are seen on all proboscis monkeys, which helps them swim.
Proboscis Monkey Habitat
Proboscis monkeys can only be found in Borneo’s rainforests, near rivers, mangroves, and marshy places. They are largely arboreal, spending most of their time in trees to evade predators. In pursuit of food, they may sometimes move to the ground.
Proboscis monkeys, like many other primates, have a complex social system. Common among men are harems of two to seven females and their children. In order to find safety in numbers, these groups often link up with other groups at night. Furthermore, there are often all-male gatherings, while others will be mostly lonely. For up to 6 or 8 years, a single guy will lead a one-male group, with turnover generally happening without violence or major antagonism.
Proboscis Monkey Diet and Predators
Proboscis monkeys are omnivores that eat largely leaves and seeds foraged from the ground and unripe fruits collected from the trees they reside in. They will also consume insects on occasion.
Large and exotic creatures such as jaguars, pythons, and crocodiles are among the species’ predators. Proboscis monkeys have also been hunted by humans in the past, with certain indigenous peoples in the region considering them a delicacy.
Males will use their long, hanging nose to amplify their calls, impressing females and intimidating other males. When looking for a mate, both sexes will make lengthy, pouting faces and other displays. After a one-minute copulation and a gestation period of roughly 170-200 days, females frequently give birth at night in the safety of a huge band. Typically, just one baby is born, and it will suckle from the mother for up to seven months. The baby will start eating solid meals at the age of 6 weeks, augmenting their newborn diet. Females reach sexual maturity at the age of five, and individual monkeys live for roughly 20 years.
Unfortunately, the Proboscis monkey is only found in one of the world’s most endangered habitats. Deforestation is displacing and harming millions of species, including the proboscis monkey, all across the world, particularly in Borneo. Because it is an island shared by three countries—Brunei, Indonesia, and Malaysia—conservation efforts in this unique and rich region are exceptionally tough.
The habitat of the proboscis monkey has become severely fragmented, forcing it to adapt its behaviour and take greater risks in the quest for food. This raises their chances of dying from predation or exposure. Populations are currently declining, and the IUCN has classified the species as endangered.
Fun Facts about Proboscis Monkey!
Proboscis monkeys aren’t as well-known as other endangered species as conservation emblems, but they’re interesting animals in their own right, and their habitats are vanishing at alarming rates. They are one-of-a-kind primates with a wealth of interesting things to learn about them.
The Swimming Monkey
Proboscis monkeys spend their whole lives near a water supply, such as coastal mangroves, jungle streams, and marshy places. Naturally, they have evolved a curious fondness for water, leaping from trees and bellyflopping into it in a funny manner.
Crocodiles, one of the most common predators of proboscis monkeys, live in these waterways. To improve their chances of avoiding these dangers, proboscis monkeys have evolved webbed feet and hands, which enable them to swim faster than they could otherwise. They have been seen to swim up to 66 feet (20 metres) underwater and traverse huge rivers.
Primates like the proboscis monkey need a way to communicate in order to sustain their intricate social systems. The proboscis monkey is known for making a variety of unusual sounds. Some have even been referred to as honks. Some of these cries are intended to scare other members of their band or group, while others are intended to be menacing.
The proboscis monkey’s broad, fleshy nose, on the other hand, may aid it in making these cries. The nose is thought to enhance the monkeys’ sounds, enabling them to go farther across the jungle and reach more monkeys than would otherwise be possible. This might be used to intimidate other men or to impress women. However, not all communication takes place in a spoken format. Proboscis monkeys also make non-verbal demonstrations, such as shaking branches and threateningly baring their fangs at others.
The Probiotic Proboscis Monkey
Proboscis monkeys have sophisticated, chambered stomachs that depend on a variety of microbes to help break down some of the tough plant matter they consume. Domestic cows, like proboscis monkeys, will “chew their cud” before enabling bacteria in their intestines to further help in the digestion of their diet.
Specifically, cellulose is found in the cell walls of plant material, which must be broken down by specific microbes. In addition to the mechanical breakdown of plant material that happens when the monkeys chew their cud, they also depend on the bacteria in their intestines to further break down their diet. By combining these factors, they are able to get the most nutritional value out of their low-nutrient diet.