Across 11 southern African reserves protecting the world’s largest rhino population, we documented the poaching of 1985 rhinos (2017–2023, ~6.5% of the population annually) despite approximately USD 74 million spent on antipoaching. Most investment focused on reactive law enforcement—rangers, tracking dogs, access controls, and detection cameras—which helped achieve >700 poacher arrests. Yet we found no statistical evidence that these interventions reduced poaching (horn demand, wealth inequality, embedded criminal syndicates, and corruption likely combine to drive even high-risk poaching). By contrast, reducing poacher reward through dehorning (2284 rhinos across eight reserves) achieved large (~78%) and abrupt reductions in poaching using 1.2% of the budget. Some poaching of dehorned rhinos continued because poachers targeted horn stumps and regrowth, signaling the need for regular dehorning alongside judicious use of law enforcement.
