(Airs Sunday, August 9) Amid the wilderness of Africa's Zambezi region unfolds a sinister tale of political upheaval, sexual intrigue, and murder in a community of chacma baboons.

Recent challenges to Titus's rule by his rival, Kuryama, have the entire group of gorillas on edge.

Whether they involve defending each other or offering gentle and nurturing support, one thing is certain -- friendships are vital to chacma baboon society.

Elephant social rules are very complex. Females dwell in tightly bonded families that stay together for life, and males live a largely solitary existence.