When the Tungara frog blurts out its mating call, an unsuspected eavesdropper listens in the trees above.
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The frog-eating bat Trachops cirrhosus has an exceptional ear for the Tungara’s call — and many other species that it likes to snack on.
The bats expertly distinguish the sounds of edible species from poisonous ones, which made researchers wonder how long they could retain sound-related memories.
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Long-term memory isn’t a given for many animals.
It can provide certain advantages, but it can also interfere with processes that they need to survive, such as quick decision-making and encoding of short-term memories.
Dixon et al, Current Biology
But in a new study published this week in Current Biology, researchers report that the frog-eating bat does appear to exhibit long-term memory when it comes to sounds.
For their study, the researchers captured 49 adult bats in the wild and trained them to recognize two artificial ringtones (played above).
The bats learned that if they flew to the speaker where the ringtone was playing, they could attack it and retrieve a bit of food.
Dixon et al, Current Biology
Over a span of four years after the bats were released, researchers re-captured a fraction of the original cohort to see if they’d remember the ringtones after time had passed.
Sure enough, the bats did — here’s one darting to the speaker after hearing the ringtone for the first time in over a year.
Dixon et al, Current Biology
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On the other hand, bats that had never heard the ringtones before reacted with confusion.
Only one out of the 17 naïve bats actually approached the speaker, but it didn’t retrieve the food.
Here’s a bat shaking its head in response to a ringtone it had never heard before.
Dixon et al, Current Biology
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The results suggest that these bats can retain memories of sound for long periods of time — a trait that could preserve their knowledge of frog and bug species, aka potential meals.
W. Perry Conway/Corbis/Getty Images
“The frog-eating bat’s remarkably long memory indicates that an ability to remember rarely encountered prey may be advantageous for this predator and suggests hitherto unknown cognitive abilities in bats.”