![]() ![]() ![]() Three studies, including two before-and-after studies, in the Congo, The Gambia and Guinea, found that most chimpanzees reintroduced into habitat with predators, alongside other interventions, survived over one to five years or increased population numbers.Two before-and-after studies in Brazil found that most golden lion tamarins reintroduced into habitat with predators, alongside other interventions, did not survive over one to seven years but reproduced succesfully. ![]() The article was first published on September 4, 2013. This article is reproduced with permission from the magazine Nature. “No one’s looked at their combinations of gestural signals and vocalizations, and that’s possibly where future discoveries will take place,” says Zuberbühler. They also want to study other primates, especially the great apes. The team now plans to play recordings of the different call sequences back to the titis to see how they react. “I’m not sure because there aren’t really good signs that the sequences have further regularities, besides the first call, or that the combinations contain further information,” he says. That’s clearly not true.”īut Kurt Hammerschmidt, who studies animal communication at the German Primate Center in Göttingen, is not convinced that the calls show the type of structural organization that the team suggests. “But when we started researching this ten years ago, the perceived wisdom was that non-human-primate calls only refer to events, without any syntactic organization or combinations. “For now, we don’t know how these calls relate to our own capacity to produce and comprehend higher-order structures,” says Zuberbühler. The latest discovery suggests that simple syntactic rules may have preceded the split of these two lineages some 40 million years ago.īy studying more species, the team hopes to better understand the origin of our own syntax. Until now, only apes and Old World monkeys were known to combine individual elements in different orders to convey distinct meanings. ![]() They are also the first New World monkeys to show signs of a primitive syntax, he adds. But the titis are the first non-human animals found to encode both a predator’s type and location in their alarms, Zuberbühler says. Some species, such as meerkats and black-capped chickadees, can even encode the urgency of the threat in their calls. Many studies have shown that animals and birds use different alarm calls for different predators. “The five different groups were almost unanimous in their response. “A single call doesn’t really tell the recipient what’s happening, but they can infer the type of predator and its location by listening to the first five or six calls,” says co-author Klaus Zuberbühler of the University of Neuchâtel in Switzerland. If the oncilla was in a tree, the monkeys made a single introductory A-call before switching to B-calls. If the caracara was on the ground, the monkeys started with at least four A-calls before adding B-calls into the mix. However, when the team moved the predator models around, the monkeys tweaked their calls. When the animals saw a ground-based threat - represented by an oncilla, a small spotted cat - they produced B-calls, sounds with a falling pitch. When the researchers placed a stuffed caracara - a bird of prey - in the treetops, the titis gave out A-calls, which have a rising pitch. Her results are published in Biology Letters.Ĭäsar's team worked with five groups of titis that live in a private nature reserve in the Minas Gerais region of Brazil. The cries are loaded with information.Ĭristiane Cäsar, a biologist at the University of St Andrews, UK, and her colleagues report that the titis mix and match two distinct calls to tell each other about the type of predator that endangers them, as well as the location of the threat. These are the alarm calls of the black-fronted titi ( Callicebus nigrifrons), a monkey with a rusty-brown tail that lives in small family units. Listen very carefully in the rainforests of Brazil and you might hear a series of quiet, high-pitched squeaks. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |