Urban bat pups take after their mothers and are bolder and faster learners than rural pups

Background Urbanization is rapidly changing our planet and animals that live in urban environments must quickly adjust their behavior. One of the most prevalent behavioral characteristics of urban dwelling animals is an increased level of risk-taking. Here, we aimed to reveal how urban fruitbats become risk-takers, and how they differ behaviorally from rural bats, studying both genetic and non-genetic factors that might play a role in the process. We assessed the personality of newborn pups from both rural and urban colonies before they acquired experience outdoors, examining risk-taking, exploration, and learning rates. Results Urban pups exhibited significantly higher risk-taking levels, they were faster learners, but less exploratory than their rural counterparts. A cross-fostering experiment revealed that pups were more similar to their adoptive mothers, thus suggesting a non-genetic mechanism and pointing towards a maternal effect. We moreover found that lactating urban mothers have higher cortisol levels in their milk, which could potentially explain the transmission of some personality traits from mother to pup. Conclusions Young bats seem to acquire environment suitable traits via post-birth non-genetic maternal effects. We offer a potential mechanism for how urban pups can acquire urban-suitable behavioral traits through hormonal transfer from their mothers.

Automated summary

The study found that urban fruitbat pups exhibit higher levels of risk-taking, learn faster, but have less exploratory behavior compared to rural fruitbat pups. A cross-fostering experiment suggested a non-genetic maternal effect as pups were more similar to their adoptive mothers. Furthermore, it was discovered that urban lactating mothers have higher cortisol levels in their milk, potentially explaining the transmission of certain personality traits from mother to pup.