TANZANIA, Nov. 2 -- AS the dust of the dry season settles, Tanzania turns green. November is the month when the short vuli rains arrive, usually as brief afternoon showers that wash the air clean and paint the plains in fresh colour. The light is softer, the skies are dramatic, and photographers find some of the years most striking backdrops for elephants, giraffes and big-cat portraits.

In the Serengeti, the great wildebeest herds are on the move once again, streaming south toward the Ndutu plains ahead of the calving season. The river crossings may be behind them, but the sight of columns of animals stretching across the grasslands is unforgettable. With the rains come newborn antelope and zebra foals, and the predators that follow, so...