Expensive prices of monkeys have many

In the world of monkey monkeys, monkeys living with two or more "husbands" often have fewer children than those with only one partner.

Owl monkeys (Aotus trivirgatus) are small primates in the Americas. Owning big eyes and fur from gray to red, they live and catch prey at night. Most monkey monkeys live with only one partner in their life. Their nuclear family consists of an adult male, an adult child and children. Male or female monkeys living with two or more partners only account for a small percentage. When a male monkey wants to live with a female monkey that has "peace of mind" , it will fight the "husband" of the object. If you win the war, it will replace your opponent. The female monkeys also snatch a partner in the same way.

Monkey lives in the "monogamous" mode like humans. (Photo: WCS)

To investigate the relationship between the number of sexual partners and the fertility of male monkeys, Pennsylvanina University scientists in the US tracked 154 monkeys from 18 large monkeys in the Chaco region of Argentina since 1997. They collected data on behavior, the number of individuals in the herd, the physical and mental health status of each child, Livescience reported.

"We can know when a monkey monkey is missing or a new monkey appears in the herd. The team can also describe each battle between male monkeys in detail, as well as the replacement process. Their partner , " said Eduardo Fernandez-Duque, the leader of the research team.

During the follow-up, Fernandez-Duque and his colleagues discovered 27 female monkeys and 23 male monkeys successfully snatching mates from others. They found that the monkeys lived only with a "husband" who had more children than the female monkeys that lived with more than one partner. If counted within a decade, the number of children that "monogamous" monkeys were born was 25% greater than the others.

The team has not found the cause of female monkeys' fertility decline if they live with two or more partners. Like humans, male monkeys spend a lot of time and effort on raising children. Therefore, experts predict that a fidelity pairing helps them increase reproductive health. In "faithful families" , male monkeys will take care of their children very carefully so female monkeys do not have to invest much time and effort. Conversely, if the female monkey lives with at least two male monkeys, the next male monkey will not care about her own children, so female monkeys have to spend a lot of time and effort on raising children. This situation reduces their reproductive health.