Left Handed Chimp Digs Wells in Uganda

Here’s something you don’t see every day: a chimpanzee digging a well. Digging for water has been observed in elephants, warthogs, wild horses, zebras … and now a primate –  the East African chimpanzee (Pan troglodytes schweinfurthii). The research appears in the journal Primates.

The researchers analyzed the behavior of chimps in the Waibira community of Uganda. There they first spied a young female they call Onyofi, an “immigrant” to this group, digging for water with such proficiency that they believe she grew up in a well-digging community of chimps elsewhere. 

Onyofi doesn’t use tools, just a very patient repetitive pawing at the muddy rainforest floor until water seeps up from below, which she sips at occasionally. She appears to be left handed. It is remarkable to see this behavior in a relatively wet environment, where fresh water isn’t so hard to find.

“What’s also interesting is that the wells all appear next to open water,” says lead author Hella Péter, “so the purpose of them is likely filtering, not reaching the water — the chimpanzees might get cleaner or differently flavored water from a well, which is fascinating.”

Also fascinating: after watching Onyofi work, other adult females, often accompanied by babies, have taken to digging for water as well. The adult males watch, without doing any dirty work themselves, but they do enjoy the fruits of the female labor.

“One of the most interesting things was seeing the other chimpanzees’ responses to Onyofi’s digging — even large dominant males would politely wait for her to finish digging and drinking, and only then go and borrow her well, which is pretty unusual around such a valuable resource,” said study co-author Catherine Hobaiter.

Here’s seven minutes of Onyofi digging in the mud, while another female and baby look on: youtube.com/watch?v=LCKbRmV_L_c&t=69s.

Photo credit: Hella Péter