Overview
- Coordinated attacks about 15 years ago killed at least 21 neighboring chimpanzees and were followed by roughly a 22% expansion of Ngogo territory.
- In the three years before the expansion, females produced 15 offspring; in the three years after, they produced 37, and under‑3 mortality dropped from 41% to 8%.
- Analyses found no evidence that changes in fruit abundance within the pre‑expansion core explained the reproductive gains.
- Researchers describe the aggression as numerically lopsided raids that isolate single victims, with deaths sometimes occurring within 12 to 14 minutes.
- The peer‑reviewed PNAS paper, led by UCLA’s Brian Wood with co‑authors John Mitani, David P. Watts, and Kevin E. Langergraber, reports a short‑lived birth surge and urges caution in drawing human parallels.