Overview
- Long-term monitoring of the Ngogo chimpanzees in Uganda documented coordinated attacks from 1998 to 2008 that killed at least 21 neighbors.
- The victorious group expanded its range by about 22 percent following the campaign.
- In the three years after the expansion, births rose to 37 from 15 in the prior three-year window.
- Juvenile mortality before age three fell sharply, dropping from 41 percent to 8 percent among offspring born after the expansion.
- Authors attribute the demographic gains to better access to food after the territorial gain, while noting that parallels to human evolution remain unresolved.