Co-existence and niche segregation of three small bovid species in southern Mozambique

Niche segregation among three small antelopes - red duiker, common duiker and suni - was investigated in a coastal savanna woodland/forest mosaic. It was expected that these similar-sized concentrate selectors would show differentiation in diet choice to decrease competition. Diet composition did not vary significantly among the different vegetation types. For all three antelope species, the number of dietary items was large, with a minimum of 70 different food items per species. Dietary specialization was low, with only 10% of the food items being exclusively used by each of the species. The ranks of food items were positively correlated among species in the wet season, but not in the dry season. Diet breadth significantly decreased in the dry season. The use of exclusive species was significantly larger in the dry season with lowest values recorded for the common duiker. Diet overlap in the wet season was considerable, but significantly decreased in the dry season, the time of food scarcity. The dry season data showed evidence for niche segregation, although this was not based on displacement. As niche segregation in the dry season was coupled to a random apportionment of diet items among antelope species, it cannot be interpreted as the result of competitive displacement.