There is a moment every Serengeti National Park safari traveler describes the same way. You are in the vehicle at dawn, rolling through the darkness before sunrise. Your guide cuts the engine. Silence. Then — slowly — the world reveals itself. The golden grass stretches to every horizon without interruption. A thousand zebras move across the plain in the half-light. Somewhere to the left, a lion coughs. The sky turns from black to purple to amber to gold. And you realize, wit