Researchers believe chimpanzees seen on camera raiding farmland for food are adjusting to pressure applied by humans on their habitats.

According to BBC News, authors of a study published in the journal PLOS One believe they have captured the first videographic evidence of one of these nighttime food raids. For their analysis, the researchers from the Museum of Natural History in Paris and the Uganda Wildlife Authority set up a camera trap in Uganda's Kibale National Park.

They described the raiding as "daring," though they believed the chimps carried them out because of human interference in their habitat. The loss of parts of their habitat may force the chimps to look elsewhere for food.

"It forces chimps to explore new food sources, like human crops," Dr. Catherine Hobaiter, an expert in chimp behavior t the University of St Andrews, told BBC News. "Raiding fields is extremely dangerous - chimps may be attacked or even killed by people defending their crops, but by raiding at night [these chimps] seem to have reduced this threat."

About eight chimps per group carried out raids and participants even included parents nursing infants.

"Such a dramatic change suggests the chimpanzees are responding to a very strong pressure to obtain the basic foods they need to survive - a response to the widespread destruction of their natural forest home," Hobaiter said. "While it might be working for now, this won't be a long-term solution."

The researchers found that the chimps would sometimes forage for food during the day, which altered their tendencies. For example, the raiders were less cautious and more venturesome at night.

"As local people become aware of these nocturnal raids they may try to defend their fields in the dark, and the risks of conflicts escalating and injury to both chimps and people is likely to increase," she said. "From a conservation perspective, the only long-term solution is the protection of the remaining forests."