Sexy Frog Moves Make Them Targets For Attack [VIDEO]

When male frogs try to put the moves on the local ladies during mating season, they may be unwittingly inviting a bat attack, according to a new study.

The study, recently published in The Journal of Experimental Biology, details how the male túngara frog's main strategy for wooing the ladies, which involves calling our while expanding its vocal sac, also makes it a target of bat predation.

Experts have long suspected this, but they were unsure what exactly was helping bats hone in on the tiny amphibian.

However, after Smithsonian Tropical Research Institute in Panama ran a series of field tests with imitation robotic frogs, they are now fairly certain that the sudden movement of an inflated vocal sac, and not necessarily the sound, is key.

The researcher made several of their robo-frogs emit sounds while puffing out inflatable air sacs while other just made sounds. Predictably, the frogs making a ruckus with their sacs quickly became the targets of bat attacks, while the solo singers were ignored.

However, when the researcher covered the frogs with transparent spheres, the bats no longer targeted sac inflation. This indicated that the bats were finding their prey by homing in on their bulging throats, not by visibly noticing the sudden movement of a swelled vocal sac.

Interestingly, compared to other frogs who employ a similar mating strategy the male túngara frog's display is very simple and underwhelming. The authors of the study suggest that this may be because eavesdropping bats have always quickly found the more impressive males before they could find a mate and reproduce.

The result is a frog society of fast, quiet, and fearful male frogs.

A similar study published in the journal Science this past February found that sometimes a male túngara will employ a third sneakier signal - using its vocal sac inflations to cause subtle ripples on a pond's surface.

However, researcher quickly found that clever bats can detect this too, tracking the ripple back to their source - a tasty and unsuspecting midnight snack.

[Credit: Wouter Halfwerk]