About 12,000 species of tiger moth exist on Earth. Some of them swoop and dive out of harm’s way when a hungry bat tries to make them a meal. But other tiger moth species are more blasé—they just don’t bother to flee from the hungry bats.

“And I really just wanted to know why. Why the difference? What factors might be influencing whether a species is more or less likely to perform these evasive maneuvers?”

Wake Forest University behavioral ecologist Nick Dowdy. He says it’s a matter of taste—some of the moths are delicious, but others are toxic and taste terrible. When the airborne predators catch these unappetizing moths, they’ll spit them out, giving the insects a new lease on life.  

In a field experiment, Dowdy and his colleague William Conner filmed how five different species of tiger moths responded to bat attacks.

“And what we found was that those species which were really toxic—so when the bats captured them, they almost never ate them—those species were much more likely to be what we call nonchalant, species that do not perform evasive maneuvers very often. On the other hand, species that were really palatable were much more likely to perform those evasive maneuvers, almost, in a sense, sort of hedging their bets. Because if they don’t make that escape, if they are captured by a bat, those species are more likely to be eaten.”

Another factor is that evasive maneuvers have their own set of risks, which may be why unpalatable moths tend to avoid them. For example, diving away from bats burns fuel, gives the insects less time to seek out mates and could... [full transcript]