In humans, love is in the beholder’s eyes. In other mammals, such as bats, detection of love is done via the nose. In the emballonurid family of bats, one in every fifty-one species of bats finds a mate with greatest genetic diversity by use of smell.
The family of bats, also known as sac-winged bats possess bag-shaped glands in all wings which are open to air. When courting, males wave wings before females for several seconds, for dispersing the scent from these bags. They mix this scent with chemical components from the wings for ensuring the molecules reach the females noses.
Pablo Santos, an author from Leibniz Institute, wrote that the acoustic communication used by the bats is essential in this particular species of bats. He also says that the chemical substances detected by smelling are necessary when the females a mating partner.
Earlier research had noted that bats do not make a choice of mates though elaborate mating dances and color displays as in the other animals. The research team then embarked on odor. A discovery came more than thirty years ago, stating that the S. bilineata species of bats create own scent by mixing saliva, perfume, and penile secretions. They place them the wing bags. However, this complex behavior is still uncertain.
The research team also made an observation that these bats spend almost one hour a day stuffing and cleaning the wing bags. With the warmth of the bat’s body, this substance starts fermenting. This team also discovered that each bat emits a powerful odor which broadcasts own chemical composition of histocompatibility complex, genotype, or MHC. The MHC is a gene family found in vertebrates and encodes essential proteins in the immunity defense system. These genes play an imperative in selecting mates, not only in bats but also in humans and mice.
After gene analysis in over 1000 bats, a study of the composition of MCH genes and their molecular structure came, and the olfactory receptor genes are TAAR2, TAAR8, and TAAR3. Since these receptors can be in various individuals, the females can possess up to receptors on the mucosa of their noses. When a female has a great variety of receptors, she will be more sensitive to the sense of smell. The females with the highest variety of TAAR receptors usually have better chances of finding an optimal partner complimenting their genetic composition.
Even though potent bats use various compounds to make the mixture of attracting females, the study says that the females have the ability to measure the genetic qualities of a male before mating.
Bernal Rodriguez, a biologist at the University of Costa Rica, says that the MCH complex is fashionable for investigation because it handles the chemical and sensory functioning parts of bats. He also says that MCH II is an immediate response to a virus by the immune system. Combining MCH and MCH II determines important decisions just like in human beings where people use olfaction while selecting partners.
Rodriguez is now fine-tuning his research to find the molecule that differs males, making some males irresistible to females. He will be finding the source of these particles. The results of this study will be interesting.