Do bat mothers teach their pups navigation?

Egyptian fruit bat

I don’t know about you, but when I’m being driven somewhere or shown around a new town, I usually don’t remember the route and I would not be able to retrace my steps, until I’ve taken that route a couple of times and paid special attention to it.

Young Egyptian fruit bats also need some repetition to learn navigation. They learn a new route while being carried (upside down!) by their flying mothers. The mothers help the young by taking the same route many times while the pups are free to look around*. This seems to be one of few documented examples of teaching in non-human animals.

Learning step by step

But even with mother’s help, learning navigation is not easy and in Egyptian fruit bats it is a four-stage process:

1. Constantly attached: During the first 1-3 weeks of life, the pup always travels with the mother, constantly attached to her.

2. Drop-off: When the pup is 3-10 weeks old, when night falls, its mother carries it to a drop-off tree, which may even be a few kilometers away from the roost. The pup stays there while mother goes foraging. But she often returns to her young and spends a large fraction of the night with it, most likely to feed and warm it. At the end of the night the mother picks up her child and takes it back to the roost.

By the end of this stage the young bats can fly and may travel between nearby known drop-off trees, but are still brought from and to the roost there by their mother.

Each mother usually uses the same tree, or trees located relatively close to each other, although they choose sites nearer (within 1.5 km) the roost as pups become heavier.

3. Independent navigation: When the pup is 8-10 weeks old, the mother leaves the roost without it and it flies to known drop-off sites independently. However, at the beginning of this stage, the mother still monitors it. She comes back to the roost and if the pup is still there, she may carry it to a drop-off tree. And if the young is not back at the roost by the end of the night the mother seeks it out and brings it back.

When flying to the drop-off trees, young bats do not follow their mothers or other bats, but use the same routes their mothers used when dropping them off earlier in life. So, they must have learned the route while being carried upside down by their mothers.

4. Exploration: From the age of 10 weeks bats leave the cave alone, travel to the drop-off sites and explore from there. During the first nights of exploration, they keep returning to the drop-off trees even if they find sources of food.

It’s not easy without a mum

In contrast, when Egyptian fruit bat pups from another colony were raised by humans and didn’t have maternal help, their first flights out of the roost were very short and most pups flew to the same fruit trees within 100m from the roost, and often did not return to the colony before sunrise.

So, the mothers definitely help their young learn multiple skills, such as independent navigation to specific trees up to 1.5 km from the roost and independent return to the roost before the sunrise.

It’s not easy to be a mum

Helping their young comes with costs. Carrying them demands energy and lowers maneuverability (mothers can carry young weighing up to 40% of their own weight). They also spend time bringing children to the drop-off trees and when visiting them, reducing their own foraging opportunities.

However, leaving pups in the same location not only helps the young learn the route, but also makes it easier for the mother to find them again, even if the pups traveled there on their own.

All in all, the research strongly suggests that Egyptian fruit bat mothers go out of their way to help their young acquire the important skill of navigation and therefore independence. It is therefore one of few known (so far) examples of teaching in animals.

* Egyptian fruit bats mainly navigate by sight, and use echolocation only at very short distances, even though they fly at night. In human-populated areas, they seem to use artificial lights as navigational marks.

Polską wersję tego wpisu możesz znaleźć tutaj.

Photo: אורן פלס Oren PelesDerivative work: User:MathKnight – File:PikiWiki Israel 11327 Wildlife and Plants of Israel.JPG by אורן פלס, CC BY 2.5,

Leave a Reply

Your email address will not be published. Required fields are marked *