Homosexual behaviors in animals is a lot more common than many may believe. Monkeys, specifically the Japanese macaque have many cases of homosexual mating. Males don’t only have to compete with other males but also females. It’s not just common it is the norm for this species. These pairing can occur hundreds of time within the same pairing according to Melissa Hogenboom.
Macaques are not the only animals that participate in same-sex relationships. Penguins are known for their long-term same-sex bonds. All snails start as a male and when they mate, one of them changes sex to female. Dolphin will touch genitalia and sometimes the males penetrate each other in the blowhole. Bottlenose dolphins specifically engage in same-sex relationships to facilitate group bonding. Some male fruit flies hunt for other males because they lack a gene that allows them to tell the difference between sexes. These are just a few examples of other animals that were discussed by Alok Jha.
There has been lots of research done to discover a reason for same-sex relations in animals. Very few studies have even considered if these relationships may have an effect on the evolution of animals. They may shape evolution subtle but very important ways. Of these few studies, it was found that same-sex relationship has been shaped by natural selection. Same-sex behaviors include courtships, mounting, and parenting.
After some research, it is suggested that homosexuality may boost the chances of reproduction being successful. For example, a study on Laysan albatross found that about a third of the couples were female- female pairs. These pairs are more successful than unpaired females when it came to reproducing and raising their young.
In some cases, the homosexual partnerships is a result of a shortage of males or a sex. Instead of having no offspring, some female pairs raised offspring together after mating with a male from an m-f pair. Animals are usually non-exclusive meaning they don’t have one sexuality, they are “bisexual”.
All in all, homosexuality in animals as well as humans does not boost nor reduce overall fitness. There is not set explanation as to why animals have these relationships but it could be different explanations for different species. I am very interested to find out if they will ever find an explanation.