article_snippet: Chimpanzees at Lincoln Park Zoo in Chicago Chicago exchanged white PVC pipes (above) for either grapes or carrots .
article_snippet: Primatologists have found that a group of adult chimpanzees from a safari park in Holland adapted the grunts a group of adult chimpanzees from a safari park in Holland produced for foods like apples to match those of other chimps a group of adult chimpanzees from a safari park in Holland lived with in Edinburgh.
article_snippet: the researchers, whose findings are published in the journal of Current Biology, watched a group of adult chimpanzees from Beekse Bergen Safari Park in the Netherlands were moved to join a group of chimpanzees in Edinburgh Zoo.
article_snippet: Future studies should test whether chimpanzees would be willing to exert more effort for more-preferred rewards if the type of effort was different - for example, time to process the food or increased competition to negotiate.'
article_snippet: Dr Hopper and her colleagues, whose research is published in the journal Peerj, gave a group of six captive-born chimpanzees at Lincoln Park Zoo rewards in exchange for small lengths of PVC pipe that the apes had to collect from a single location.
article_snippet: a group of six captive-born chimpanzees at Lincoln Park Zoo could exchange these 'tokens' at one of two locations - a close by one that gave a group of six captive-born chimpanzees at Lincoln Park Zoo a carrot reward or one further away that gave a group of six captive-born chimpanzees at Lincoln Park Zoo a grape.
article_snippet: Over the course of 15 months the researchers changed the locations of the food to see how a group of six captive-born chimpanzees at Lincoln Park Zoo would react.
article_snippet: a group of six captive-born chimpanzees at Lincoln Park Zoo behaviour could be seen as surprising in the context of wild chimpanzees where animals will often have to take food where animals can find it.
article_snippet: In addition to learning about food preferences and proximity, we also observed innovative, problem-solving behavior among the chimpanzees.'
article_snippet: Chimpanzees, like the one above, are our closest living relatives in the animal kingdom and our closest living relatives in the animal kingdom behaviour
article_snippet: Dr Hopper added that the findings could also help zoos improve the way zoos care for chimps.
article_snippet: Dr Hopper said: 'In captivity, primates are provisioned with food by human caretakers and so have reduced choice over the options available to primates. '
article_snippet: Unlike wild primates that spend a large proportion of primates waking hours foraging for food, captive primates are typically fed following a regular schedule. '
highlights_snippet: Biologists at Lincoln Park Zoo in Chicago offered chimps carrots or grapes .
  
highlights_snippet: The apes exchanged 'tokens' made of PVC tubes for the food The apes wanted .
  