Gorongosa National Park is where ivory poaching pushed elephants to evolve without tusks. Through Mozambique's civil war, from 1977 to 1992, fighters on both sides shot the park's elephants and traded the ivory for weapons, killing roughly 90 percent of them — and the guns passed over the animals that had no ivory to take. Researchers comparing wartime film with the surviving herds found that tuskless females had climbed from about 19 percent to 51 percent in 28 years, and tracked the trait to a gene on the X chromosome: evolution measured inside a single elephant generation, published in Science in 2021. The park it happened in covers 4,067 square kilometres at the southern end of the Great African Rift Valley — grassland and fever-tree woodland around Lake Urema, a shallow lake that swells from roughly 10 square kilometres to as much as 200 when the rains come, and Mount Gorongosa, 1,863 metres high and added to the park in 2010, whose rainforest holds birds found on no other mountain.
An aerial survey in 1994 counted five elephants, six waterbuck and three zebra in the whole valley. Since 2004 the Mozambican government and the Carr Foundation have run the restoration together, and the tally reads differently now: around 200 lions, buffalo and elephant herds back on the plains, and so many waterbuck — tens of thousands, the largest population of the species in Africa — that surveyors photograph the floodplain rather than count them one by one. Wild dogs were released in 2018 after 25 years of absence, leopards from 2021. You meet all of it from an open vehicle with a park guide, driving the floodplain at dawn and dusk; self-driving is not permitted, and the rains shut the park completely from mid-December to the end of March.