A family of cotton-top tamarins (Sanguinus oedipus) at Manattan’s Central Park Zoo has been caught whispering.
The tamarins are the first non-human primates to be observed using whisper-like behavior, reported Rachel Morrison and Diana Reiss in Zoo Biology this month (September 13). The researchers, based at Hunter College in New York City, intended to investigate mobbing behavior, where a group of animals swarms a perceived threat and vocalizes loudly.
The scientists expected the tamarins to react strongly to one of their supervisors, toward whom they displayed mobbing behavior in the past. But the primates instead displayed fearful behaviors, approaching cautiously and then shying away from the supervisor.
At the time, the researchers did not detect any vocalizations. Only upon listening to audio recordings did they observe “low amplitude vocalizations” like whistles and chirps, akin to human whispering.
“Consistent with whisper-like behavior, the amplitude of the tamarins’ vocalizations was significantly reduced only in the presence of the supervisor,” the authors reported in their paper, suggesting that the primates were using the whispers to communicate with each other.
“Male orangutans plan their travel route up to one day in advance and communicate it to other members of their species. In order to attract females and repel male rivals, they call in the direction in which they are going to travel. Anthropologists at the University of Zurich have found that not only captive, but also wild-living orangutans make use of their planning ability.
For a long time it was thought that only humans had the ability to anticipate future actions, whereas animals are caught in the here and now. But in recent years, clever experiments with great apes in zoos have shown that they do remember past events and can plan for their future needs. Anthropologists at the University of Zurich have now investigated whether wild apes also have this skill, following them for several years through the dense tropical swamplands of Sumatra.
Orangutans communicate their plans
Orangutans generally journey through the forest alone, but they also maintain social relationships. Adult males sometimes emit loud ‘long calls’ to attract females and repel rivals. Their cheek pads act as a funnel for amplifying the sound in the same way as a megaphone. Females that only hear a faint call come closer in order not to lose contact. Non-dominant males on the other hand hurry in the opposite direction if they hear the call coming loud and clear in their direction” (read more).
Two researchers have provided the first video-based observation of swimming and diving apes. Instead of the usual dog-paddle stroke used by most terrestrial mammals, these animals use a kind of breaststroke. The swimming strokes peculiar to humans and apes might be the result of an earlier adaptation to an arboreal life.
For many years, zoos have used water moats to confine chimpanzees, gorillas or orangutans. When apes ventured into deep water, they often drowned. Some argued that this indicated a definitive difference between humans and apes: people enjoy the water and are able to learn to swim, while apes prefer to stay on dry land.
But it turns out that this distinction is not absolute. Renato Bender, who is working on a PhD in human evolution at the School of Anatomical Sciences at Wits University, and Nicole Bender, who works as an evolutionary physician and epidemiologist at the Institute of Social and Preventive Medicine at the University of Bern, have studied a chimpanzee and an orangutan in the US. These primates were raised and cared for by humans and have learned to swim and to dive.
'We were extremely surprised when the chimp Cooper dived repeatedly into a swimming pool in Missouri and seemed to feel very comfortable,' said Renato Bender.
To prevent the chimp from drowning, the researchers stretched two ropes over the deepest part of the pool. Cooper became immediately interested in the ropes and, after a few minutes, he started diving into the two-meter-deep water to pick up objects on the bottom of the pool. ‘It was very surprising behavior for an animal that is thought to be very afraid of water,’ said Renato Bender. Some weeks later, Cooper began to swim on the surface of the water.
The orangutan Suryia, who was filmed in a private zoo in South Carolina, also possesses this rare swimming and diving ability. Suryia can swim freely up to twelve meters.
Both animals use a leg movement similar to the human breaststroke ‘frog kick’. While Cooper moves the hind legs synchronous, Suryia moves them alternatively. The researchers believe that this swimming style might be due to an ancient adaptation to an arboreal life. Most mammals use the so-called dog-paddle, a mode of locomotion that they employ instinctively. Humans and apes, on the other hand, must learn to swim. The tree-dwelling ancestors of apes had less opportunity to move on the ground. They thus developed alternative strategies to cross small rivers, wading in an upright position or using natural bridges. They lost the instinct to swim. Humans, who are closely related to the apes, also do not swim instinctively. But unlike apes, humans are attracted to water and can learn to swim and to dive.
As my followers may know, I am an Ambassador for the UK based primate charity, Wild Futures, which, as well as aiming to protect primates and habitats worldwide, campaigns for the primate pet trade to be made illegal in the UK. They are currently running a competition, where 5 lucky people can win a monkey adoption pack! Give it a go, learn a little about Wild Futures’ sanctuary and work, help to raise awareness of the horrific primate pet trade….and you may well gain a monkey friend, too!
Win a free ‘adopt a monkey’ package and help to raise awareness of our Sanctuary!
Watch our new video produced by Chris Jones called The Monkey Sanctuary, and complete the following questions to be in with a chance of winning one of five adopt a monkey packages for a monkey of your choice.
1.What type of monkey first appears on the film?
2.Name at least one of the capuchins that appears in the film (refer to www.adoptamonkey.org for photos and clues).
3.What is the name of the person being interviewed on the film?
4.What year did The Monkey Sanctuary start?
5.What fruit is given to the woolly monkeys during the film?
6.What was the name of the first rescued capuchin monkey at the Sanctuary?
7.Identify at least two behaviours we encourage among the monkeys at The Monkey Sanctuary.
8.Identify the seeds given out by keeper, Claire.
9.How many monkeys are estimated to be kept as pets in the UK?
With your name
Your answers numbered to the corresponding question
With the subject title ‘The Monkey Sanctuary Video Competition’
Closing date for this competition is Sunday 18th August at 5.00pm. Entrants with all correct answers will be put into a hat and chosen at random. If you are a winner you will be contacted on Monday 19th August.
Deforestation, hunting, and poaching have combined to push 25 primates to the precipice of extinction, according to a new report from the United Nations.
The endangered species—which include rare primates like the red ruffed lemur, the golden-headed lemur (seen above), and the Grauer’s gorilla—are spread across Asia, Africa, and South America.
One of the most critically endangered groups is the northern sportive lemur, which lives in Madagascar—shockingly, only 19 are known to live in the wild.
"Lemurs are now one of the world’s most endangered groups of mammals, after more than three years of political crisis and a lack of effective enforcement in their home country, Madagascar," Christoph Schwitzer of the Bristol Conservation and Science Foundation, one of the groups involved in the study, told AP.
"A similar crisis is happening in Southeast Asia, where trade in wildlife is bringing many primates very close to extinction," Schwitzer said.
These primates’ survival is critical for maintaining biodiversity.