The southern short-grass plains around Ndutu hold the herds from about December to March. This is calving season: roughly half a million calves are born in a concentrated few weeks around February, and the predator activity that follows is the most intense wildlife viewing of the entire year.

The Western Corridor and the Grumeti river take the herds through roughly May and June. Grumeti crossings are real but usually smaller and less dramatic than their Mara counterparts, since there is often not enough water in the river for the classic chaos.

The northern Serengeti and the Mara river are where the famous crossings happen, roughly July to October. Crossings cannot be scheduled — herds can mass on a bank for hours or days before going — so build in several days near the river rather than one.

The Seronera valley in the centre is the exception to all of this. Its year-round water supports resident game whatever the migration is doing, and it holds arguably the most reliable lion and leopard viewing in the park — the fallback that makes a non-migration-season trip worthwhile.

Cheetah favour the open southeastern plains where they can run; black rhino are present but rare and largely confined to protected pockets. Across the whole park, the first two hours after sunrise and the last two before dark are what matter, with cats often active well after the midday lull in the cooler months.

Practicalities

Most visitors combine the Serengeti with the Ngorongoro Crater on the drive up from Arusha, and internal flights to the park's airstrips save two long days on the road. Mobile tented camps that relocate with the herds are the standard answer to the migration's movement — a fixed lodge in the wrong sector in the wrong month is the most common and most expensive planning mistake here.