To the west of the Seronera the Serengeti branches out along the westerly reaches of the Grumeti River, in an area called the Western Corridor. This area is more wooded than the Seronera, and although it still has a good population of resident game it is harder to spot them in the bush. It is worth taking a guide who knows the area. This region is particularly worth visiting in June and July, when the migration moves northwards from the Seronera and must face up to the often fatal challenge of jumping across the crocodile-infested Grumeti River. Many of these resident crocs rely entirely on this spring-time annual feast, and spend the subsequent months of the year in an idle, yellow-toothed, mud-covered wait.