The diversity of bat mating behaviors inspires a sappy celebration of courtship, attraction, friendship, and racy behavior.

02.12.24

By Karin Akre

We’re all wondering the same thing this February… Can bats teach us anything about romance for Valentine’s Day?

Bats are an obvious match with Valentine’s Day, given that they boost cacao production for chocolatiers by eating the insects that damage cacao crops. But bats’ role in this holiday extends far beyond helping to make chocolate. The diversity of their mating behaviors inspires a sappy celebration of courtship, attraction, friendship, and racy behavior.

greater sac-winged bat, Bruce D. Taubert

Courtship and Attraction

Bat courtship strategies are surprisingly similar to our own. Dousing themselves with perfume, singing or screaming to express desire… It’s all pretty familiar. But bats can take these actions to a level of intensity that might be a turn-off to your human love interest.

Detail of sac on wing which is used to attract females and mark territory, Christian Ziegler/Minden Pictures

Some bats make their own DIY perfume by producing smelly fluids and creams with their own bodies and then wafting them through the air to influence other bats. Male sac-winged bats (Saccopteryx bilineata) have a special sac-like body part–one pocket on each wing–that they fill with ingredients exuded from genital and jaw glands, along with urine and saliva. Upon achieving the right odor, males either shake their wings to strategically distribute this elixir, or they hover in front of females to fan the scent towards her. This attractive gesture helps her choose a mate. Is that love I smell in the air?

The heavily perfumed sac-winged bats sing complex courtship songs along with their odorous displays, but some bats have a different taste in music that’s a little more hard-core. Hammer-headed bat (Hypsignathus monstrosus) males advertise for mates by performing in a lek. This mating system is much like an outdoor music festival with multiple stages competing for attention. Each male honks, yells, and buzzes loudly from his own roost, wing flapping like any confident rockstar. Many males perform close together, and females can survey all their options before choosing the most attractive male to mate with. Interestingly, some males have serious star power that others lack—only a few males attract most of the females.

Friendship

If Galentine’s Day is more your style, bat behavior can also inspire a celebration of platonic friendships. The best example of this type of bat bonding is in common vampire bats (Desmodus rotundus). These misunderstood bats form long-lasting supportive relationships with both family and unrelated bats through grooming each other and with a behavior that looks a lot like kissing. When one bat returns to the roost full of a blood meal (they lick blood from small cuts in sleeping animals), she will share it with a hungry friend who hasn’t eaten recently. To do this, she vomits part of the blood meal into the other bat’s mouth. Kissing, mouth-to-mouth blood vomiting, what’s the difference really? Whatever you call it, it helps hungry bats survive, and it forms long-term close relationships between specific bats. #BFF

Risqué Behaviors

Bats have a surprising number of racy behaviors that make us blush.

Swarming is a bat behavior that is hard to describe without making it sound like a giant raging party for swingers. Before hibernation, many northern hemisphere bat species attend swarming events by gathering in large groups of up to thousands of individuals. At a suitable cave or mine, these groups fly around in a flurry of chasing, finding quick opportunities to mate in the chaos. In this setting, bats find mates from other colonies, increasing the population’s genetic diversity.

The giant bat swinger parties are not even the most blush-inducing bat mating science to report. For example, multiple bats, such as the short-nosed fruit bat (Cynopterus sphinx) and the Indian flying fox (Pteropus giganteus), have been found to use oral stimulation to increase the duration of their mating events, which may increase the chances of successful fertilization. In addition, the Bonin flying fox (Pteropus pselaphon) uses oral stimulation in same-sex interactions for undetermined reasons.

serotine bat, Jeroen van der Kooij

The precise mechanics of bat mating vary across mating systems and with the size and shape of the relevant organs. Bats’ reproductive organs differ in interesting ways. For example, the body parts of serotine bats (Eptesicus serotinus) present a confusing problem. The male penis averages 16.4 mm long and ends in a 7.5 mm wide heart-shaped bulge, while the female genital tract averages a short 2.3 mm long with an outer diameter of 1.1 mm. Scientists learned how the bats resolve this problem through video analysis revealing that this species can mate without actually inserting anything anywhere. The male simply touches the heart-shaped end of his “copulatory arm” (scientists came up with this name) to the external surface of a female’s genital area, and he deposits sperm right there, with no penetration.

In Conclusion…

Between lekking and licking, the entertainment value of understanding bat mating behavior is clearly enormous. But it pales in comparison to the conservation value of understanding what bats need for successful reproduction and survival. Protecting access to abundant insects, roost-laden lekking trees, undisturbed swarm-friendly caves, and other important bat resources will help support the world’s bats and the warm fuzzy feelings they inspire.

Karin Akre, Ph.D.

Science Writer

Dr. Karin Akre joined Bat Conservation International as our Science Writer in September 2023. She supports scientific research to inform conservation actions for bats by creating engaging and informative content for diverse audiences. She contributes to scientific articles, grant proposals, and outreach materials.

Karin has over 20 years of experience in science writing and research. She has published scientific articles on the evolution of behavior, and she taught animal behavior and conservation courses at the University of Texas, Austin and Hunter College. Prior to working for BCI, she wrote and edited K-12 science textbooks, encyclopedia articles, and science-based television scripts. Her writing translates complex scientific information into language that can educate and inspire audiences to increase their awareness of conservation topics.

Karin received her Ph.D. in ecology, evolution, and behavior from the University of Texas, Austin and a bachelor’s degree from Harvard University in psychology and biology.

You May Also Like