New study shows that apes, whose natural habitat is endangered by human activity, organize cropland robberies. In fact, food is stolen by the large groups despite the danger that members will be captured or beaten by local farmers. “More surprisingly, chimpanzees were crop-raiding during the night. They also stayed longer in the maize field and presented few signs of vigilance and anxiety during these nocturnal crop-raids,” authors of the article published on the PLoS ONE say.
“Today anthropogenic activities, including commercial logging, poaching, mining, illicit trade of wild animals and agricultural land encroachment are severely threatening the tropical forests and the survival of fauna, including great apes, our closest relatives,” the researchers emphasize.
Lack of food in their natural homes forces our close relatives to steal harvest of the local farmers. These endeavors, however, are pretty dangerous. For example, 40% of the population studied by Sabrina Krief and her colleagues had limb mutilations caused by the snare traps. But how they are doing it? What behavioral strategies are employed during these raids? Are these attacks well organized?
“To investigate the hypothesis that they use specific strategies for incursions out of the forest into maize fields to prevent the risk of detection by humans guarding their field, we carried out video recordings of chimpanzees at the edge of the forest bordered by a maize plantation in Kibale National Park, Uganda,” the scholars explain.
Video recordings reveal some interesting facts. First of all, these activities are performed in large groups. Not only males, but also females are engaged in these activities. Moreover, they bring their children as well. It seems that the largest part of the prize is consumed on site. This finding is a bit strange, because it is easier to detect large parties than small ones. Nonetheless this observation can be explained by another curious fact.
Although primates are usually active during the day time, they learned to organize their invasions during the night. This can minimize the chances of detection. “To our knowledge, this is the first report of long, repeated and group night activities by a great ape species outside of moonlit nights. As of today, the nightlife of chimpanzees has been neglected and we have probably missed some interesting activities as night-time lasts around half of each 24 h in the equatorial regions,” the biologists claim.
Article: Krief S., Cibot M., Bortolamiol S., Seguya A, Krief J-M, et al., 2014, Wild Chimpanzees on the Edge: Nocturnal Activities in Croplands. PLoS ONE 9(10): e109925. doi:10.1371/journal.pone.0109925, source link.