A Dynamic Process in the Open Savannah

When dealing with an area that is about 1,400 km² counting wild game is easier said than done!

The animals occur over a diversity of habitats all with differing degrees of visibility, they move over space and time, often sporadically, and accessibility to certain areas is sometimes difficult. Grumeti Reserves is part of an open system so animals are always moving in and out of the area.

To be able to compare trends over time, consistency in the counting method is very important. Using helicopter counts, every year in August, game are counted using the DISTANCE sampling method.

By using DISTANCE, you do not have to see all the game. It is more important to record the distances at which game are seen accurately. The program then works out a density and area estimate. However, it is important to have a good number of sightings per species, at least 60, to develop more accurate estimates.

The below table shows species trends for the period 2003-2008. These figures are estimates – the data reported is not a total count but rather the mean estimates for the species.

Wildebeest and zebra are the primary migratory species in the Serengeti ecosystem. While the general migration pattern is relatively consistent, how they move over this vast landscape shifts slightly each year. This accounts for the variation in numbers counted each year. Higher counts are likely to contain a component of the migration, while lower counts are more reflective of resident populations.

Game Population Count 2003-2008

	2003	2004	2005	2006	2007	2008
Wildebeest	2759	19160	**	53225	50297	9580
Zebra	15651	3149	**	30427	18267	47905
Elephant	355	744	**	892	629	770
Giraffe	331	668	**	864	880	803
Buffalo	605	733	**	2248	3124	3815
Warthog	435	907	**	2429	2432	2551
Impala	7147	9394	**	9967	10218	11942
Coke’s Hartebeest	189	259	**	414	469	525
Eland	254	1090	**	1286	1211	2330
Reedbuck	1005	501	**	706	1557	1690
Waterbuck	212	498	**	462	499	770
Thompson’s Gazelle	3480	19707	**	18506	17105	22606
Grants Gazelle	200	205	**	229	263	248
Topi	5705	6587	**	10342	11409	14770

** No survey done due to lack of funding

Game populations in the area recovered significantly from 2003 to 2008. This is mainly due to an effective law enforcement program and minimal human disturbance. The consistent trends for other species elude to the high numbers of resident game within the area which make for superb game viewing all year round.