With regal manes, hairless scarlet chest patches, and intimidating canines jutting from their mouths like scythes, it would be easy to think gelada monkeys were the rulers of their mountain domains.

That would be wrong.

No one gets off easy on nature's grasslands.

To understand just how difficult survival can be on a treeless grassy landscape, consider the world of the gelada, sometimes called the bleeding heart monkey. This primate spends its days searching for calories in low-quality vegetation on the high savanna along Africa's roof. Nights are for cowering in the cold and rain while clinging to steely straight basalt cliffs. In between there are fights, frights, and endless flights, from predators real, and, sometimes, imagined.

"We've always thought of them