Wild bats discovered to possess advanced cognitive abilities previously considered exclusive to humans

Researchers at Tel Aviv University have tracked free-ranging Egyptian fruit bats from a colony based at TAU’s I. Meier Segals Garden for Zoological Research to answer a longstanding scientific question: Do the animals have the ability to high and complex cognitive, previously attributed only to humans? In particular, the study focused on the traits of episodic memory, mental time travel, planning ahead, and delayed gratification, arriving at some pretty thoughtful conclusions.

The work was published in Current Biology.

The study was directed by Prof. Yossi Yovel and Dr. Lee Harten of the School of Zoology and the Sagol School of Neuroscience at Tel Aviv University. Other researchers included Xing Chen, Adi Rachum, Michal Handel and Aya Goldstein from the School of Zoology; Lior de Marcas of the Sagol School of Neurosciences and Maya Fenigstein Levi and Shira Rosencwaig of the Israel Ministry of Health’s National Public Health Laboratory.

Prof. Yovel explains, “For many years, the cognitive abilities to recall personal experiences (episodic memory) and plan ahead were considered exclusive to humans. But more and more studies have suggested that various animals also have such abilities, but almost all these studies were conducted under laboratory conditions, since field studies on these issues are difficult to conduct.In an attempt to test these abilities in wild animals, we designed a unique experiment relying on the colony of of free-ranging fruit bats based at TAU’s I. Meier Segals Garden for Zoological Research”.

The researchers hypothesized that bats dependent on fruit trees for their survival must develop an ability to track food availability both spatially (where are the fruit trees?) and over time (when does each tree bear fruit ?). Navigating through landscapes with numerous fruit trees and nectar, they will need to mentally track the sources in order to revisit them at the right time.

To test this hypothesis, a small high-resolution GPS tracker was attached to each bat, enabling documentation of flight paths and trees visited over many months. The vast amount of data collected in this way was thoroughly analyzed, producing some surprising results.

The first research question was: Do bats form a temporal map in their minds? To explore this issue, the researchers prevented the bats from leaving the colony for varying periods of time, from a day to a week.

Dr. Harten says, “We wanted to see if the bats could sense that time had passed and behave accordingly. We found that after a day in captivity, the bats would return to the trees visited the night before. However, when a whole week had passed, the older bats, based on past experience, avoided trees that had stopped fruiting in the interval.

“In other words, they were able to estimate how much time had passed since their last visit to each tree, and they knew which trees bore fruit for a short time and were no longer worth visiting. at night, the young, inexperienced were unable to do this. indicating that this is an acquired skill that must be learned.”

While the first research question examined past experiences, the second addressed the future: Do bats exhibit future-oriented behaviors? Are they able to plan ahead? To address this issue, the researchers observed each bat’s path to the first tree of the evening, perhaps indicative of plans made before leaving the colony.

Researcher Chen Xing says, “We found that bats usually fly directly to a specific tree they know, sometimes 20 or 30 minutes away. Being hungry, they fly faster when that tree is further away, suggesting that plan where they’re going. Furthermore, focused on their chosen target, they’ll pass by other trees, even good sources visited only yesterday—showing a knack for delayed gratification, we also discovered. that the first bats to leave the colony choose trees that bear sugar-rich fruit. The bats that leave later look for protein.”

All these findings suggest that bats plan their foraging before they leave the colony and know exactly where they are flying and what kind of food they are looking for.

Prof. Yovel adds, “The cognitive gap between humans and animals is one of the most fascinating questions in science. Our study shows that fruit bats are capable of a fairly complex decision-making process that involves the three questions that indicate cognitive abilities: Where? (the location of each tree) when the tree bears fruit (the food it provides).

“Once again, we find that the gap is not clear, and that humans are not as unique as some might think. Apparently, humans and animals are all located on a spectrum, with almost every human ability found also to animals.”