A bat’s willingness to take risks in the wild may depend less on its innate personality and more on the conditions it experiences early in life, according to TPS-IL. The study provides rare experimental evidence that the environment in which young animals are raised can have a lasting influence on how they behave as adults in natural settings, with implications for wildlife rehabilitation.
The research was led by doctoral student Adi Rachum at Tel Aviv University’s School of Zoology, under the supervision of Prof. Yossi Yovel. While scientists have long observed that some bats behave more boldly than others, the origins of these differences have remained unclear. The new findings suggest that early-life experience can outweigh inborn tendencies when it comes to shaping behavior in the wild.
To examine this question, the researchers raised 40 Egyptian fruit bats in two sharply contrasting environments during their first months of life. One group grew up in an enriched and constantly changing setting, where the bats had to cope with new challenges each day in order to obtain food. The second group was raised in a stable and predictable environment with few changes. After several months, all of the bats were released into the wild, and their movements were tracked using GPS devices that recorded every flight.
Clear and consistent differences emerged.
Bats raised in the enriched environment behaved far more boldly after release. They traveled greater distances from their home colony, spent longer periods outside each night, and explored much larger foraging areas. On average, these bats ranged across about eight square kilometers, compared with roughly three square kilometers among bats raised in the stable environment. They also ventured farther from the colony and remained active for close to four hours per night, compared with less than three hours in the control group.
What makes the findings especially notable is that these behavioral differences could not be explained by innate personality. Before being exposed to the two environments, the young bats were assessed in the laboratory for individual personality traits. Those traits did not predict how the bats later behaved in the wild, indicating that early experience, rather than inborn disposition, was the decisive factor.
“Fruit bats are animals with remarkable behavioral flexibility and learning capacity,” Rachum said. “We found that the early environment to which bats are exposed influences the way they explore the world.”
Yovel said the findings may help explain previously observed differences between bat populations. “In previous studies, we identified behavioral differences between exploratory urban bats and more ‘conservative’ rural bats,” he said. “The current findings may explain how these differences between the groups are formed.”
Beyond advancing basic understanding of animal behavior, the researchers say the results have practical implications. The findings suggest that animals raised for release into the wild should be exposed early on to varied and challenging environments, rather than simplified and predictable ones, to better prepare them for survival.
The study also suggests **improving** captive breeding and reintroduction programs by emphasizing environmental complexity during early development. In addition, the results reinforce the importance of environmental enrichment in zoos, research facilities, and breeding centers, indicating that such enrichment plays a critical role in healthy behavioral development rather than serving merely as an optional welfare measure.
The study was published in the peer-reviewed journal eLife.
