Katavi’s dominant feature is the 425-sq-km Katisunga Plain, a vast grassy expanse at the heart of the park. This and other flood plains yield to vast tracts of brush and woodland (more southern African than eastern), which are the best areas for sighting roan and sable antelopes (together with Ruaha National Park, Katavi is one of the few places you have a decent chance of spotting both). Small rivers and large swamps support huge populations of hippos and crocodiles and Katavi has more than 400 bird species.
The park really comes to life in the dry season, when the flood plains dry up and elephants, lions, zebras, giraffes, elands, topis and many more gather at the remaining waters. The park really stands out for its hippos – up to a thousand at a time can gather in a single, muddy pool at the end of the dry season (late September to early October is the best time) – and its buffaloes. Katavi is home to some of the largest remaining buffalo herds in Africa and it's not unusual to see over a thousand of these steroid-fuelled bovines at any one time.