Monkey dogs also know how to prevent pregnancy

African bitches know how to self-prevent pregnancy when pregnant for a few weeks in the event that a new male monkey has just appeared in order to prevent the children of the 'predecessor' being attacked by the new leader. killing. This interesting study by American biologists has just been published in Science.

Bruce effect

In the middle of the 20th century, the British female biologist Hilda Bruce commented that laboratory female mice knew how to 'miscarry' themselves in the event of a new male appearance. This phenomenon is called 'Bruce effect' by scientists. Since then biologists have repeatedly confirmed the existence of this effect in other animals.

The team of biologists led by Jacinta Beehner of the University of Michigan discovered 'the effect Bruce' exists in both populations of wild monkeys (Theropithecus gelada) living in Africa in a research project. Their decades long.

The female monkeys will miscarry themselves if the population appears new leader.

They had long known that the females in these monkeys always sought to 'pair' with 'the number 2 character' capable of overthrowing the incumbent 'number 1' . Usually in other monkey species one never saw a pregnant female monkey (with the leader, of course!) Bear to let the 'No. 2 character' flirt, even when the character won. gain power. But in dog monkeys, 'Bruce effects' occur frequently.

Cruel behavior of dogs monkeys

Beehner and her colleagues rechecked this many times when tracking the childbirth of 21 dogs of monkeys, living in the 'Mount Simien' National Park located in Ethiopia.

Often, 'character 2' came to power, it would turn 'to communicate' with each female monkey in the pack because the 'law' in the monkeys is that all female monkeys are in the harem of the monkeys.

According to scientists, the average gestation period of female monkeys is 6 months (183 days). Any child born before this timeline is a descendant of the former leader (and must be killed) and after that landmark can only be the son of the new leader.

Biologists keep track of the time when a 'figure 2' appears and the time the new monkeys were born in the pack. In the experiments, the researchers periodically collected the droppings of female monkeys to analyze the female sex hormone estrogen in it. This concentration allows determining whether or not a monkey is pregnant at the correct time.

In all the monkeys studied, Beehner and his colleagues all noticed a "child boom" after six months of new leader rule. This proves the existence of the 'Bruce effect' in dog monkeys.

Hormonal analyzes confirm this conclusion. According to scientists, about 80% of the monkeys stopped pregnant during the first 2 weeks after changing the leader in the herd. At that time, female monkeys may be at different stages of pregnancy and in some cases, their pregnancy time is up to 150 days.

Biologists affirmed that this self-miscarriage effect is to allow female monkeys to not lose their strength to become pregnant and give birth because the newly born monkeys are killed by the new leader. for the reason is the blood of the former leader. Abandoning a pregnancy that has been 'trapped' will shorten the time between two pregnancies from 3.5 to 2.5 years. This increases the number of potential children for female monkeys to raise.