Counting Creatures of the Serengeti, Great and Small

Serengeti National Park, Tanzania—It's just after dawn, and in the dense woodlands along the Grumeti River the birds are beginning their morning chorus. This is prime data-collecting time for ecologists A.R.E. Sinclair and Simon Mduma of the University of British Columbia (UBC) in Vancouver, and they bend their heads and cup their ears to better hear the bird calls. “That's two gonoleks singing their duet; the cooing is a green pigeon; and that harsh cry is a gray-headed kingfisher,” says Sinclair. Mduma and Sinclair's wife, Anne, jot down the species on their data sheets. Crouching low, Sinclair listens again, then creeps forward, following a hippo's trail through the dark stands of fig and African olive trees. Silently, he points to an oval circle of mashed grass and ferns where the hippo had rested, then raises his eyebrows in mock alarm at the bus-length crocodile stretched on a sandy beach across the river. But it's the birds Sinclair is after, and a few moments later when he first hears and then sees an olive-green bulbul, he smiles broadly. “They are rare and hard to see,” he whispers, “and so are exactly the kind of bird we're trying to find by creeping around like this. It's the kind of species most likely to vanish if we lose these forests.”