Understanding factors limiting rare species is a major concern in conservation ecology. Little is known about how large mammalian bovid species from West Africa partition diet resources, and to what extent the rare topi antelope and other sympatric bulk grazers can cope with this co-existing system. Using tooth collagen stable isotope data, we studied an assemblage of three sympatric grazers (topi, hartebeest and roan) with different population density. Our findings showed numerous patterns in resource partitioning amongst the three sympatric species studied, suggesting that the species used dietary resources in contrasting ways. There were significant differences in both δ¹³C and δ¹⁵N signatures among topi, hartebeest and roan. A very narrow range could be noticed for the rare topi antelope (−6.05‰ to −7.63‰) for δ¹³C values and no significant differences at individual scale. The more abundant species such as hartebeest and roan were found to use a high proportion of the isotopic niche space of topi (more than 70%), while topi used only a narrow range of hartebeest and roan niche space (less than 10%). Our study provides the first evidence for the resource partitioning amongst high and low density ungulates in West African savanna. Expansion of the niche noted in the roan and hartebeest is much more related to the strong variation of the niche at the individual level. Topi, as subordinate species narrow their niche instead of expanding the dietary niche as expected. Our findings regarding the absence of dietary niche flexibility observed in the topi despite it being considered as subordinate species were discussed in being one of the factor limiting its population recovery in West African grazer assemblages.

了解限制稀有物种的因素是保护生态学的主要关注点。对于来自西非的大型哺乳动物牛科物种如何分配饮食资源，以及稀有的topi羚羊和其他同伴大批放牧者能够在多大程度上应对这种共存的系统，鲜为人知。使用牙齿胶原蛋白稳定同位素数据，我们研究了三种不同种群密度的同伴放牧者（topi，hartebeest和roan）的组合。我们的发现表明，在研究的三个同胞物种中，资源分配的模式众多，这表明该物种以相反的方式使用饮食资源。有两个δ显著差异¹³ C和δ ¹⁵在topi，hartebeest和roan之间有N个签名。一个非常窄的范围内，可以注意到对于罕见托皮羚羊（-6.05‰至-7.63‰）为δ ¹³C值在个体规模上无显着差异。发现更丰富的物种（例如，羚羊和罗恩）使用了高比例的topi同位素生态位空间（超过70％），而topi仅使用了狭窄范围的hartebeest和roan生态位空间（不到10％）。我们的研究为西非热带稀树草原高密度和​​低密度有蹄类动物的资源分配提供了第一个证据。罗恩和羚羊中提到的利基市场的扩张与个体层面利基市场的强劲变化密切相关。托皮（Topi）作为从属物种缩小了其生态位，而不是像预期的那样扩大了饮食生态位。