CHOBE NATIONAL PARK, Botswana (AP) — No sign of an elephant in all of two minutes, a tourist teased a guide at Botswana’s Chobe National Park, home to tens of thousands of elephants. A minute later, their vehicle cleared a knot of shrubs and elephants loomed ahead beside the dusty road.

Such joking wouldn’t be possible in many other parts of Africa, where recent years have yielded dire news about ivory poaching. Poachers killed more than 20,000 elephants in 2013 amid rising demand for their tusks in Asia, particularly China, according to international conservation groups.