Scientists have captured monkeys doing a strange type of breast stroke on camera.

The swimming style could come from an early adaptation, a Wits University press release reported.

Apes drown more easily than humans, are less inclined to take a swim. Past reseachers have claimed this is a fundamental difference between humans and primates, but this may not be the case.

"We were extremely surprised when the chimp Cooper dived repeatedly into a swimming pool in Missouri and seemed to feel very comfortable," who is a PhD candidate in human evolution at the School of Anatomical Sciences at Wits University Renato Bender.

As a safety precaution, the researchers stretched a length of rope across the pool so the chimp wouldn't drown.

After a few minutes Cooper started to dive into the six-foot-deep water to search for objects put there by the researchers.

"It was very surprising behavior for an animal that is thought to be very afraid of water," Bender said.

After several weeks, Cooper started to swim on the water's surface.

 An orangutan, Suryia, was also filmed swimming up to 40 feet.

Both primates displayed a similar "frog kick," which is significantly different from the doggie-paddle normally seen in mammals.

Humans and primates must learn to swim, unlike other animals that can do it instinctually.

"The behavior of the great apes in water has been largely neglected in anthropology. That's one of the reasons why swimming in apes was never before scientifically described, although these animals have otherwise been studied very thoroughly. We did find other well-documented cases of swimming and diving apes, but Cooper and Suryia are the only ones we were able to film. We still do not know when the ancestors of humans began to swim and dive regularly,' Nicole Bender, an evolutionary physician and epidemiologist at the Institute of Social and Preventive Medicine at the University of Bern, said.

"This issue is becoming more and more the focus of research. There is still much to explore," said Renato Bender, said.