Why It Matters for Saving the Species: Black Rhinos Are Mostly Loners, but Not Always

Why moving rhinos is risky

Black rhinos can be aggressive toward people and other rhinos. Injuries from fights are a common cause of death, and this reputation has helped leave their social behaviour relatively underexplored.

Translocation is a key conservation tool: managers move rhinos to strengthen existing populations or establish new ones. But clashes between residents and newcomers, or among animals moved together, can put those efforts at risk.

A conservation effort in southern Africa

The Black Rhino Range Expansion Project brings together WWF South Africa, Ezemvelo KZN Wildlife, Eastern Cape Parks and Tourism, and reserves. For more than 20 years, it has worked to establish breeding populations across southern Africa.

The project’s work also benefits populations that supply animals, because black rhinos survive and breed more effectively at lower population density. The International Union for Conservation of Nature estimated 6,788 black rhinos in Africa in 2024; 516 were killed by poachers that year, 81% of them in South Africa.

What the sightings revealed

Researchers examined 69,920 sightings of 542 black rhinos across 14 reserves. Nearly seven in ten sightings involved a single animal, while 22.7% involved two, mostly mothers and young. Groups of three to seven made up 8.1%.

When rhinos interacted, they usually did so with animals they had encountered before, and they avoided adult males. Adult females had the most associates. Females were seen more often with females, while males were somewhat more often seen with males; this pattern was particularly clear among calves.

Implications for translocation

The findings suggest managers could reduce aggression after release by considering existing relationships when choosing which rhinos to move, as well as the animals’ sex. The study also found that calves had lower long-term survival when they interacted frequently with unrelated rhinos. The researchers suggested stress from repeated contact with potentially aggressive animals may help explain the association.