About the Authors
Wildlife Conservation Society, Mbeli Bai Study, Nouabalé-Ndoki Project, Brazzaville, Republic of Congo
Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
The authors have declared that no competing interests exist.
TB conceived and designed the study. TB, MNH, and VF performed the study. TB analyzed the data and contributed reagents/materials/analysis tools. TB and VF wrote the paper.