The scientists could rule out that the investigative staring into the treetops was triggered by the sight or smell of fruit. Rather, the analysis of the footage suggested that the chimpanzees control these trees in anticipation of finding fruits for consumption there in the near future. According to the researchers, the animals know that some tree species bear fruit at the same time and use this botanical knowledge in their daily foraging. So when the fruits of a particular tree are ripe, chimpanzees inspect other tree species carefully to see if they are already bearing fruit.
Researchers can predict which trees will visit the animals
The chimpanzees base their expectations on a combination of two abilities, the researchers explain: They can distinguish tree species and assign seasonal Eastern varieties. "The chimpanzees do not just develop a fondness for a particular fruit that they often ate in the past, " says Karline Janmaat. "We can predict which trees the animals will inspect based on the simultaneous fruit production of certain tree species." Display
The discovery also sheds light on human development history, the researchers say: "Our results show the variety of strategies our next relatives, the chimpanzees, have developed in foraging. This also highlights the evolutionary origins of the human capacity for categorization and abstract thinking, "says co-author Christophe Boesch, head of the Department of Primatology at the Max Planck Institute for Evolutionary Anthropology.Karline Janmaat and Christophe Boesch (Max Planck Institute for Evolutionary Anthropology in Leipzig) et al .: Animal Cognition, April 10, 2013 © wissenschaft.de - Martin Vieweg