The arm reaching for Lake Victoria
The western corridor is the long westward projection of Serengeti National Park, running from the centre of the park almost to Lake Victoria. It is narrower than the rest of the park, greener, and cut lengthways by the Grumeti River and its belt of gallery forest.
That forest is the reason the corridor matters. TANAPA records rare primates here that most visitors do not associate with the Serengeti at all: red patas monkeys and black-and-white colobus, both named by the authority as occurring in the western corridor of the park. Riverine forest in the middle of a savanna ecosystem produces that kind of anomaly, and the primate watching guide covers where else in Tanzania they are found.
What else is here
Resident topi and giraffe are characteristic of the corridor. The Grumeti’s deep pools hold very large Nile crocodiles and hippo. The migration passes through on the northward leg and crosses the river in a scattered way along its length rather than at concentrated points, which makes the western crossings a quieter and less predictable proposition than the Mara ones.
The corridor also has more visible human history than the rest of the park. Fort Ikoma, a German fort built at the end of the 1890s, stands on a low hill about a mile north of the Grumeti. Beyond the northern boundary lie Grumeti Game Reserve and Ikorongo Game Reserve, both part of the wider Serengeti–Mara ecosystem as TANAPA defines it.
Access, which is the real difference
The western corridor is the part of the Serengeti reached most easily from the wrong direction. TANAPA’s Ndabaka gate sits at the far western end, on the Mwanza side, with a public campsite the authority says needs no booking; Handajega is the other western gate. The Kirawira airstrip serves the corridor and there are park cottages at Kirawira.
For a traveller arriving from Arusha by road, the corridor is the far end of a very long drive. For one arriving from Mwanza on Lake Victoria, it is the nearest part of the park by a wide margin. That asymmetry, rather than the wildlife, is what usually decides whether the corridor is in an itinerary.
TANAPA lists walking safaris in the western part of the park with a skilled armed park ranger, and balloon flights operate over the west among other parts — see walking safaris and balloon safaris.
The honest case for and against
In favour: different habitat, different animals, far fewer vehicles than the centre, and a river with crocodiles and hippo in it all year.
Against: it is a long way from everything else on a northern circuit, the big-cat viewing is less consistent than at Seronera, and the crossings here rarely produce the spectacle people have come for. A short first Serengeti trip is generally better spent elsewhere. A second one, or a trip combining the Serengeti with Lake Victoria, is where the corridor comes into its own.
Common questions
Are there colobus monkeys in the Serengeti?
Yes, in the western corridor. TANAPA names black-and-white colobus and red patas monkeys as occurring there, in the riverine forest along the Grumeti.
Is the western corridor good for the migration?
The herds pass through on the northward leg, but the Grumeti is crossed in a dispersed way rather than at mass crossing points. Expect a quieter and less predictable version of the phenomenon.
How do you reach the western corridor?
Ndabaka gate at the far west and Handajega are the road entries, and the Kirawira airstrip serves the area. It is much closer to Mwanza than to Arusha.