Scents can even give information about genetic fitness, identity, and relatedness to potential mates. For example, a female can 'sniff out' a male immune system that is different from her own. That perhaps makes him more attractive, because it would be beneficial to their offspring who would be protected by more diseases.
Biologists are studying the science of scent among a group of lemurs. They wanted to know if hormone alteration, such as birth control, would affect a female's ability to pick up these scents.
In fact, it did! Altered hormone levels changed their own chemical signals. This made these females smell funny (from a lemurs point of view), making them less attractive to the males and making it harder for them to sniff out a mate.
- Birth Control Messes with Monkey Business (WiredScience)
- Hormonal Contraceptives Alter Scent Communications (DukeUniversity)