Wild bats show surprising cognitive abilities once thought exclusive to humans

Fruit bat. Credit: Yuval Barkai.

Researchers at Tel Aviv University have discovered that wild Egyptian fruit bats possess high cognitive abilities previously believed to be unique to humans.

This study, published in Current Biology, focused on traits like episodic memory, planning ahead, and delayed gratification.

The findings are quite thought-provoking and suggest that the gap between human and animal intelligence is not as wide as once believed.

The research was led by Prof. Yossi Yovel and Dr. Lee Harten from Tel Aviv University’s School of Zoology and Sagol School of Neuroscience.

The team included several other researchers from the same university and the National Public Health Laboratory of Israel’s Ministry of Health.

“For many years, it was thought that only humans could recall personal experiences (episodic memory) and plan ahead,” explained Prof. Yovel.

“But more studies are showing that animals might have these capabilities too.

However, most of these studies were done in labs, making it hard to know if wild animals could do the same. So, we decided to test these abilities in wild bats.”

The researchers chose to study bats that rely on fruit trees for survival. These bats need to remember where and when they can find fruit, so the researchers thought they might have developed advanced cognitive abilities.

To test this, they attached tiny high-resolution GPS trackers to the bats, allowing them to track the bats’ flight routes and the trees they visited over several months.

The first question the researchers wanted to answer was whether bats form a time map in their minds. To test this, they prevented the bats from leaving their colony for different lengths of time, ranging from one day to a week.

Dr. Harten explained, “We wanted to see if the bats could tell how much time had passed and adjust their behavior. After one day of captivity, the bats returned to the same trees they visited the night before.

But after a week, older bats avoided trees that had stopped bearing fruit, showing they could estimate the time that had passed. Younger, less experienced bats couldn’t do this, indicating that this skill is learned.”

The second question was whether bats could plan for the future. The researchers looked at the bats’ routes to the first tree they visited each evening to see if they showed signs of planning ahead.

Researcher Chen Xing said, “We found that bats usually fly directly to a specific tree they know, sometimes traveling 20 or 30 minutes to get there. They fly faster when the tree is further away, suggesting they plan their route. They also pass by other good trees, showing they can delay gratification. Early-leaving bats choose trees with sugary fruits, while later bats look for protein-rich fruits.”

These findings suggest that bats plan their foraging trips before leaving their colony and know exactly where they are going and what kind of food they are looking for.

Prof. Yovel concluded, “The cognitive gap between humans and animals is one of the most fascinating issues in science.

Our study shows that fruit bats are capable of complex decision-making involving the questions: Where? When? and What? This indicates that humans and animals are not as different as some might think. It seems that many human abilities can be found in animals too.”