Become an assassin for lack of sex

Due to the lack of regular mating, the male of a monkey in Brazil seeks to kill weaker males to increase access to females.

Monkey muriqui - living in Brazil's Atlantic forest - is considered one of the most gentle primates in the world. But perhaps their image will change after scientists witness a group of six muriqui monkeys attacking an adult. The ill-fated animal, an old male, died about an hour after being bitten into the face, body and genitals.

In the northern area of ​​Atlantic Forest, monkey muriqui have a pleasant life because the leaves (their main food) are plentiful. Here they live in large flocks and males always patiently line up to mate with females.

But the new fruit is the monkey's favorite food in the area south of the Atlantic Forest (where the attack occurred). According to Mauricio Talebi, a scientist at Sao Paulo-Diadema University (Brazil), due to the wide distribution of fruits, female monkeys must leave the herd to look for them. This makes males in the herd have less chance of mating than their peers in the northern region.

A muriqui monkey with his son in the Atlantic forest.
(Photo: Comciencia)

Due to the lack of regular relationships, the temperament of the males gradually changes. They become aggressive and agitated . Usually male muriqui monkeys have a fairly close relationship with the same blooded males. So they often attack single males to eliminate competitors in love games.

'The blood-related males naturally have a greater advantage than a single one. So males with fewer brothers face a greater risk of losing their lives in the war for their children , 'explained Filippo Aureli, a scientist at John Moores University (UK).

According to Aureli, this finding shows that lifestyle can completely change the behavior of a species. If the monkey muriqui in the Atlantic forest also likes to eat leaves as their companion in the north, perhaps brutal attacks will not happen.