Gorillas Watching TV

You could go to the zoo every day for a year and never learn the color of a zebra's penis. Go to Kenya, though, and male zebrahood is hard to miss: They hang like exclamation points. Elsewhere in the Serengeti you'll see the tumescent member of a lion as it bites its mate, or watch bull elephants full of lust, weeping pheromones, and dragging their own gray logs through rocks and thorny...