The Maasai Mara carries lions at about the highest density ever recorded, across fifteen hundred square kilometres of open grass in southwest Kenya that Maasai families have never stopped grazing cattle on. The second half of that is not incidental. It is a national reserve, not a national park, and that status left the Maasai their grazing rights: the herders in red shúkà cloth are on their ground, and some take you home into their villages. The thickest lion country is around Musiara, where marsh meets a ridge of fig trees; the Marsh Pride there has been on film for decades. The cool hour after dawn is when that ground shows what it holds: cats coming in from the night, elephants in file with the calves inside. A cheetah will be up on a termite mound reading the plain; your guide reads tracks and alarm calls. Balloons lift in the dark and hang over the grass while the first light runs across it below you.
From late July the river takes over. More than a million wildebeest and zebra come north out of the Serengeti behind the rain, and the reserve narrows to a few bends of the Mara. The herd piles onto a bank thousands deep and waits, sometimes for hours. Nothing signals the moment, so you pick one bend and give it the day. Then one animal goes in and the rest follow in a mass, and the crocodiles that have lain there nearly foodless all year move into the current. A Nile crocodile can fast for months, which suits a river whose one feast comes in the same few weeks each year. Some drown, most climb out the far side and keep walking, and it is over in minutes. Around the reserve lies a ring of conservancies — Maasai land, pooled plot by plot by hundreds of families and leased to camps that pay by the acre. So the herd that climbs out keeps walking into unfenced country, kept open because that grass is worth more to the families who own it with lions on it.