Alex Roberts, Wikimedia Commons
The five most athletic primates are named in the world's most comprehensive guide on primates, "Handbook of the Mammals of the World" (Lynx Edicions, 2013), released this week.
The number one athletic monkey, according to the guide, is the Patas monkey. Editors Russell Mittermeier, Anthony Rylands and Don Wilson write that these "are the fastest primates, relying on their speed to escape from predators." Their running speed can reach up to 34 miles per hour.
Russell Mittermeier, Conservation International
The indri is the largest living lemur. "Its hind limbs propel it through the trees in leaps up to 30 feet," according to Mittermeier, Rylands and Wilson. The leaps allow the lemur to efficiently travel high in the forest canopy, where it searches for food such as tender leaves, seeds, fruits and flowers. The leaps also often allow it to jump out of the way of predators, like hawks that can go after young indri.
Russell Mittermeier, Conservation International
The weight-lifting champ of the group is the bearded capuchin. These primates "can lift heavy rocks and smash them down to crack open palm fruits," according to the editors.
The bearded capuchin, also known as the black-striped capuchin, was the first non-ape documented to use tools in the wild. Over the years, the monkeys have evolved strong back and leg muscles that enable them to walk on their hind legs while carrying stones.
Muhammad Mahdi Karim, Wikimedia Commons
"Long-tailed macaques are skilled swimmers and can catch fish with their own hands," Mittermeier, Rylands and Wilson share. These primates sleep in trees alongside rivers, taking time to select their roosting sites. When a predator approaches, they frequently jump into the water and swim out of harm's way.
David Emmett, Conservation International
"Gibbons are masterful acrobats, swinging hand over hand with uninterrupted leaps through the forest canopy," according to the editors. Their relatively tiny size -- about 20 inches long -- makes them even faster as they glide through the air. Their swinging lifestyle allows them to exploit fruits and other foods that larger bodied arboreal animals cannot reach.
Showing instructional videos to monkeys in the wild has proven to be a resounding success, finds a new study that describes the first known usage of such videos in an animal’s native habitat.
The study, published in the latest issue of Biology Letters, opens the door to further instruction of animals, both wild and captive.
“I believe that videos and other instructional tools can indeed accelerate the learning of non-human primates and also other non-human animals,” lead author Tina Gunhold told Discovery News.
“Such instructional tools might even have the potential to be used in conservation programs where animals in captivity have to learn certain skills before they get released to the wild,” added Gunhold, who is a researcher in the University of Vienna’s Department of Cognitive Biology.
For the study, she and colleagues Andrew Whiten and Thomas Bugnyar produced videos showing marmosets demonstrating different foraging techniques used to open an artificial fruit. They then set up an elevated box in the Atlantic Forest of Aldeia, Pernambuco, Brazil. Marmosets living in the forest, who had never before seen the marmosets featured in the videos, could scale a viewing platform to watch the footage.
The primates “were immediately attracted to the video box,” Gunhold said. They lined up in front of it like kids fixated on a television show, with one big difference.
“They need to be constantly on alert and have to scan their surroundings for potential danger,” she explained. “Therefore, their attention span is quite short.”
Some of the marmosets could view the entire video, but others were just shown a static image with no instructional value.
The marmosets were then given a chance to open the artificial fruit themselves. Those that watched the instructional video performed the task much more successfully. It is probable that they also taught others what they learned.
“Common marmosets represent an ideal subject species to study social learning, as they live in small family groups, show high levels of social tolerance and exhibit a cooperative breeding system, where the father and other family members take great care of the infants,” Gunhold said.
Marmosets watch an instructional video.Tina Gunhold
“Consequently,” she added, “young individuals have access to a big ‘information network’ within the family and ample opportunities to learn from both parents and siblings.”
Instructional videos have already been used as enrichment for captive animals, such as chimpanzees, gorillas, zebra finches, and Japanese macaques. Differences in visual systems can affect the success of such efforts, since some animals literally see the world differently than humans do. Marmosets, for example, do not process colors precisely the same way, so the researchers presented the videos in grey scale.
Some animals might also think that the demonstrator on the screen is a live, present animal that could pose a threat. For the new study, however, the marmosets seemed to know that the demonstrators were not there in the flesh.
Scottish Primate Research Group member Erica van de Waal, commenting from a savanna full of vervet monkeys, told Discovery News that the “instructional video technique is great,” especially from a research standpoint, since it gives scientists a better look at how animals learn.
Charles Snowdon, a professor of psychology and zoology at the University of Wisconsin, Madison, agrees with van de Waal. He also said, “It is a major advance to demonstrate that video techniques can facilitate social learning in the wild.”
“The implications are several,” he continued. “For example it is important to teach rehabilitated or reintroduced animals what foods are valuable and how predators are to be avoided. This method can facilitate that teaching by understanding better what variables are important to wild and to reintroduced animals in being able to learn how to forage, on what foods to forage and how to recognize and avoid predators.”
“Thus, there are several important applications of this method for future work.”