According to new research, frog-eating bats trained to identify a phone ringtone with a nice food were able to recall what they learned for up to four years in the wild.
Long-term memory of frog-eating bats
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The experiment introduced 49 bats to a succession of attention-getting ringtones and taught them to correlate flying toward only one of the tones with a reward: a baitfish lunch.
Eight of those bats were caught and subjected to the food-related ringtone again between one and four years later.
They all flew toward the sound, with six of them flying to the speaker and grabbing the food reward, indicating that they anticipated finding food.
The unusual tones did not affect control bats who had never been exposed to them before.
While a graduate student at the University of Texas in Austin, lead author May Dixon, a postdoctoral fellow in evolution, ecology, and organismal biology at The Ohio State University, led this study at the Smithsonian Tropical Research Institute in Panama.
She explained that the habitat in which earlier generations lived might be vastly different from the one in which an animal is born and that it can also change through time.
Understanding how animals use learning and memory is one method to figure out how they'll survive in today's environment of constant change.
Individual frog-eating bats were kidnapped for a series of cognition tests and were exposed to a very appealing sound in the lab: the male tungara frog's mating cry, one of this species' favored food.
A piece of baitfish was placed on mesh above the speaker as a reward for flying to that sound.
The sound became combined with and then replaced by a ringtone over time, but the reward remained the same.
Three more ringtones were later introduced, none of which were linked to a food incentive.
Bats were taught to distinguish between the two and finally stopped flying toward the unrewarded noises.
Over 11 to 27 days, each bat collected at least 40 treats by flying to the taught ringtone.
Gerald Carter, associate professor of evolution, ecology, and organismal biology at Ohio State, stated that being able to study memory in the wild is crucial.
You can't always generalize from the vast amount of data we have on animals in the lab to what they'll face in the wild, where they'll have to remember a lot more.
In the wild, the environment is different, and the brain is different than in captivity.
Despite our predisposition to believe that having a lengthy memory offers our species a cognitive edge, nature reminds us that memory flexibility, also known as adaptive forgetting, is crucial for survival.
From southern Mexico to southeastern Brazil, the Fringe-lipped Bat may be found in lowland to mid-elevation (1,400 meters above sea level) tropical woods.
This bat's colonies are typically tiny (usually less than 10 individuals). They frequently roost with other birds. Hollow trees, caverns, road culverts, and buildings are also common roosting locations.
The wart-like lumps on the lips and snout of the Fringe-lipped Bat may be employed to exude toxin-neutralizing substances from the skin of the frogs it eats.
Large ears, long woolly hair, and a serrated nose leaf distinguish them. Panama has one of the best-studied populations of this bat, including individuals that appear to specialize in frogs as a dietary source.
The Fringe-lipped Bat's social organization is currently unclear. Males have been seen with an orange "crust" on their forearms, which they appear to develop through unusual grooming and clawing activities.
This crust also has a characteristic odor, which might be used by female bats to indicate physical status.
