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Check out adorable photos of the most beautiful monkey on earth and their behaviours

One of the largest monkey species native to Asia, the proboscis monkey is a big species. Only the Tibetan macaque and a few gray langurs come close to matching its size. The species has a lot of sexual dimorphism. Males normally weigh 16 to 22.5 kg (35 to 50 lb) and have a head-to-body length of 66 to 76.2 cm (26.0 to 30.0 in), with a maximum known weight of 30 kg (66 lb). Females have a head-and-body length of 53.3 to 62 cm (21.0 to 24.4 in) and weigh 7 to 12 kg (15 to 26 lb), with a maximum known mass of 15 kg (33 lb).

The male's big nose, or proboscis, which can reach 10.2 cm (4.0 in) in length and hangs lower than the mouth, adds to the dimorphism. According to some theories, their long noses are due to sexual selection by females who prefer louder vocalizations, with the size of the nose raising the amplitude of the call. Despite this, the female's nose is still very large for a primate.

The fur on the back of the proboscis monkey is bright orange, reddish brown, yellowish brown, or brick-red. Light-grey, yellowish, or greyish to light-orange underfur. Infants are born with a blue face that darkens to grey after 2.5 months. By 8.5 months of age, the face has taken on the color of an adult's. The male has a black scrotum and a red penis. The monkeys' stomachs are bulging in both sexes, giving them a pot belly appearance. The toes of many of the monkeys are webbed.


Social behavior

Labuk Bay, Sabah, Borneo, Malaysia (composite image, from right to left).

Proboscis monkeys live in groups that usually consist of one adult male, a few adult females, and their offspring. It's possible that all-male groups exist. Some people, mainly males, live alone. In a fission-fusion society, monkey groups live in overlapping home ranges with little territoriality, with groups meeting at sleeping sites as night falls.

There are bands that form when groups come together and then split up, but groups may also form to mate and groom. Individuals only groom and play with those in their own group. Groups gather during the day and travel together, but individuals only groom and play with those in their own group. Bands can have as many as 60 members, while one-male groups can have as few as 9–19 members. One-male groups usually have three to twelve members, but they may have more. While serious aggression is rare among monkeys, minor aggression does occur.

Members of the same bands are generally respectful of one another. Females have a hierarchical dominance structure. Males in one-male groups will live for six to eight years in their groups. Replacements of resident males tend to take place without much adversity. Males abandon their natal groups and enter all-male groups as they reach adulthood. Females often leave their natal groups on occasion, perhaps to prevent infanticide or inbreeding, to minimize food competition, or to improve their social status.


At the age of five, females reach sexual maturity. Sexual swelling occurs, resulting in pinking or reddening of the genitals. Matings are more common between February and November at one place, while births are more common between March and May. Copulations usually last about a minute. From behind, the male will catch the female by the ankles or torso and climb her.

Both sexes will encourage mating, but they are not always successful. When soliciting, both sexes will make pouted faces. In addition, males will sometimes vocalize and females will present their backsides and shake their head from side to side. Mating pairs are sometimes harassed by subadults.


Mounting without a reproductive intention, such as playful and same-sex mounting, is also possible, and females will attempt to initiate copulation even after they have conceived. Gestation lasts about 166–200 days or slightly longer. Females are more likely to give birth late at night or early in the morning. After that, the mothers eat the placenta and lick their babies clean. At six weeks, the babies start eating solid foods and are weaned at seven months. A young male's nose grows slowly until he reaches maturity.

The mother will let her child be held by other members of her community. The infants are at risk of infanticide when a resident male in a one-male group is substituted.


Proboscis monkeys have been observed making a variety of vocalizations. Males use honks to communicate the status of the party. They have a special honk that is directed at babies and can also be used to reassure them. Alarm calls are often produced by males to signal threat. Danger calls are made by both sexes, but they are distinct. Females and inexperienced individuals will also make so-called "female calls" when they are upset. Low-intensity agonistic interactions are marked by honks, roars, and snarls. In the same cases, nonverbal displays include leaping-branch trembling, bare-teeth open mouth attacks, and erection in males.

Content created and supplied by: Edifnews (via Opera News )

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