Black rhinos are very aggressive towards one another during non-estrus periods and mating is often preceded by the female attacking the male. Males are solitary. Females are usually found together with a calf and sometimes an older daughter. Territories are marked by spraying urine or by depositing dung piles. Although conflicts arise when strangers move through an occupied area, rhinos are usually tolerant of familiar rhinos in adjacent territories.
Rhinos take mud and dust baths to keep cool and discourage biting insects.
They feed primarily in the morning and evening on twigs and leaves and especially like to eat thorny vegetation. Their acute sense of smell is their primary method of detecting danger. Puffing snorts and grunts, repeated, signal an alarm call or an angry charge at speeds of up to 35 miles per hour. This is being accomplished through programs of research and on-going animal exchanges. For example, Cleveland Metroparks Zoo's male rhino was transferred from the Cincinnati Zoo and the female arrived from Addo National Elephant Park in South Africa.