What animals have sex for pleasure?

Infidelity in the animal kingdom


Polygamy is common

In contrast to monogamous animals, a polygamous creature mates with several representatives of the opposite sex. The better is the enemy of the good: Staying together faithfully only works until one of the two partners has a prospect of an even more beautiful female or an even better endowed male.

Ladybugs, for example, change their sexual partner about every two days. Even more highly developed animals indulge in partner swapping. Between 98 and 99 percent of mammals are polygamous.

Male lions, for example, regularly enjoy themselves with different ladies in their harem, just like our closest relatives, the primates. Whether orangutans, gorillas, chimpanzees or bonobos: there are hardly any exclusive partner relationships among the great apes.

Reasons for cheating

The reasons for the polygamous behavior of the animals are varied. On the one hand, infidelity pays off in evolutionary terms. It ensures that a large genetic variability is guaranteed.

That means: the more often the members of a group change their sexual partner, the more different combinations of genetic material there are and the higher the chance of survival of the species.

The offspring of unfaithful animals are endowed with very different characteristics, as they combine the genes of different parents. This expands the possibilities of the species to adapt to changed climatic conditions or a new food supply.

On the other hand, infidelity also has a social effect. In female bats of the species "greater horseshoe bat", for example, it is quite common for daughter, mother and grandmother to mate with the same male. Studies show that this has a positive effect on social cohesion within the bat colony.

It is similar with the bonobo monkeys. They often resolve conflicts in the group through sex - even with same-sex members. In some animal species, infidelity also promotes a sense of community.

Risks and side effects of infidelity

As positive as the effects of the infidelities on the conservation of the species may be, they are sometimes severely punished. The female red-backed forest salamander, for example, perceives the foreign sexual scents of the rival on the skin of "her" male and outlaws his infidelity with violent bites.

Dealing with the incarnate consequences of the infidelity is sometimes very brutal. While the cuckoo children often grow up unnoticed in the nests of coal tits, the male mountain gorillas usually kill the strange young.

Even with chimpanzees, foreign offspring usually have no chance of survival, since the males only tolerate their own children. The female chimpanzees therefore pursue an interesting strategy: They use loud mating calls to attract the attention of as many males as possible and have sex with many of them in a short time. In this way, the females protect their possible offspring from fatal attacks by the males, as the males are now unsure who the baby came from.

Having sex with many partners increases the risk of contracting sexually transmitted diseases. Female ladybirds can, for example, acquire a mite from their sexual partners, which makes them sterile.

The consequences are apparently even more drastic with bumblebee women. Here, infidelity supposedly lowers life expectancy. Researchers have found that bumblebees that have sex with different males are less fit in all respects than those that have only one partner. The reason for this seems to be the harmful side effects of the male semen. So infidelity is not all positive.

Author: Lena Ganschow