Fig. 4.

Number of social partners among middle- to late-adolescent and young adult male chimpanzees at Ngogo, Kibale National Park, Uganda, 3 yr prior to the attack on Erroll. The total number of individuals each male (a) groomed, (b) spent time within 5 m of, and (c) spent time associating in the same party across a 1-yr period between 2014 and 2015. Each point represents an individual male. Erroll is represented by a red point. The solid horizontal line is the mean value, and the dotted lines represent 1 standard deviation above and below the mean.