Nature
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Female Egyptian fruit bats are finicky lovers, but their desire for a mate may be swayed by his ability to provide food, according to a new study published in Current Biology. Researchers in Israel have observed captive Egyptian fruit bat females literally taking food from the mouth of willing males.
The rest of this article is behind a paywall. Please sign in or subscribe to access the full content."We found a strong relationship between producer-scrounger feeding interactions and reproduction," said study author Yossi Yovel of Tel-Aviv University in a statement. "Namely, females bore pups of the males they often scrounged food from."
At first, the team says they were confused by the bats’ behavior: Why would a male willingly give up his food? To answer, they observed three colonies over the course of a year and noticed that females would eat from the mouths of males for weeks at a time as a sort of bat dinner date. After some time, females would choose which of the many feeding males she wanted to mate with and ultimately produce offspring with him. However, being a “very consistent food collector” did not influence the male bat’s reproductive success. Furthermore, there was almost no overlap between males preferred by each female – females chose their partner based on some sort of individual preference that changed from year to year.
In their study, the authors listed off a number of reasons for sharing food, from contributing to the overall fitness of the colony to not being willing to risk fighting a female over food for fear of injury. Mostly though, the males were probably just trying to get sex.
“We hypothesize that the observed relation between food scrounging and mating is a form of mutualism exhibited in delayed reciprocity: scrounging food from a successful male forager diminishes the costs of foraging and is compensated, if consistent over time, by rewarding the male with mating opportunities,” wrote the authors, citing support for a food-for-sex hypothesis. “In addition to direct nutrition, food sharing might contribute to reducing predation risk.”
Other species have displayed similar food-for-sex relationships. Vampire bats, for example, share blood to create reciprocity in colony members. Chimpanzees also form social bonds when sharing food.
It’s unclear whether Egyptian fruit bats exhibit similar traits in the wild, but their relatively long lifespan and social demeanor make them an ideal candidate for future studies.
