Lopé National Park is where the world learned how many mandrills travel together: 845 animals in a single group, filmed as the column poured across open grass. Counts over three years averaged 620, the largest stable group known in any wild primate. They can be counted only here, because Lopé is broken up by patches of savanna, while the rest of the mandrill's range is closed forest that hides everything inside it. Those grasslands are a relic of the last ice age, roughly 15,000 years old, and by rights they should be gone: about 1,450 millimetres of rain falls here a year, enough to grow rainforest. They survive because they burn. Where fire stops, the forest moves in, and one patch left unburned closed over into young woodland within fifteen years. To keep the grass open, the park now lights controlled fires.
This grassland is natural rather than cleared farmland, and the animals use it. Forest elephants and buffalo step out of the treeline into the open in the cool hours, and a slow boat on the Ogooué river gives you sightlines that rainforest almost never allows. Guides walk you to engraved outcrops where iron tools hammered spirals into the stone about 2,000 years ago. The dry season, June to September, dries the trails and brings the big mandrill groups onto the grass, though the sky above them is more often grey than blue. Researchers here have checked the same trees for ripening fruit since 1986, and that record now reads as a warning: ripe fruit has fallen by 81 percent, and the elephants that live on it are measurably thinner than they were a decade ago. Gabon protected this landscape in 1946, made it a national park in 2002, and UNESCO listed it in 2007.