After a five-year-long civil war ended in 2003, it was easier for scientists to conduct field research in the Congo. The first scientist to see the Bili apes, and also recruited by Ammann, was Shelly Williams, PhD, a specialist in primate behavior. Williams reported on her close and chilling encounter with Bili apes, "We could hear them in the trees, about 10 m away, and four suddenly came rushing through the brush towards me. If this had been a mock charge they would have been screaming to intimidate us. These guys were quiet, and they were huge. They were coming in for the kill – but as soon as they saw my face they stopped and disappeared."