Herds of up to 300 elephants scratch the dry river bed for underground streams, while migratory wildebeest, zebra, buffalo, impala, gazelle, hartebeest and eland crowd the shrinking lagoons. It's the greatest concentration of wildlife outside the Serengeti ecosystem and the one place in Tanzania where dry country antelope such as the stately fringe-eared oryx and peculiar long-necked gerenuk are regularly observed.
During the rainy season, the seasonal visitors spread out over a 20,000 sq km range until they exhaust the green plains and the river calls once more. But Tarangire's mobs of elephant are easily encountered, wet or dry.
The swamps, tinged green year round, are the focus for 550 bird varieties, the most breeding species in one habitat anywhere in the world.
On drier ground you find the Kori bustard, the heaviest flying bird; the stocking-thighed ostrich, the world's largest bird; and small parties of ground hornbills blustering like turkeys. More passionate bird-lovers might keep an eye open for screeching flocks of the colorful yellow-collared lovebird, and the somewhat drabber rufous-tailed weaver and ashy starling.Tarangire's pythons climb trees, as do its lions and leopards, lounging in the branches where the fruit of the sausage tree disguises the twitch of a tail.