Diets of savanna ungulates from stable carbon isotope composition of faeces
Diets of savanna ungulates from stable carbon isotope composition of faeces
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DOI：
10.1111/j.1469-7998.2007.00292.x
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发表时间：
2007-09-01
影响因子：
2
通讯作者：
Fourie, N.
中科院分区：
文献类型：
--
作者：
Codron, D.;Codron, J.;Fourie, N.
解释非洲有蹄类动物多样性的假说主要集中在沿浏览器/食草机连续体的生态位分离。然而，一些研究主张，食虫/食虫的区别不能充分描述发生在分类群内和分类群之间的饮食差异的全部程度。不同的分类方案之所以存在，是因为许多分类群缺乏统一和可靠的数据，也没有将时空差异纳入对饮食的更广泛评估。在这项研究中，我们使用南非克鲁格国家公园19种物种粪便中C-3(BROWSE)和C-4(草)摄入比例的稳定碳同位素证据，测试了非洲稀树草原有蹄类动物食物和食物生态位分离的预测。文献中的饮食预测在以下情况下得到了证实：浏览器(黑犀牛、长颈鹿、长颈鹿、斑马鹿、野马)、混合食性动物(黑斑羚、斑羚)，以及大多数食草动物(白犀牛、伯切尔斑马、非洲河豚、河马、大斑羚、水鹿)。相比之下，几个物种的结果与现有文献中的大多数预期不同，包括斑羚、野猪、灰斑羚、水牛合欢咖啡、长角羚羊和黑貂。这些差异中的许多可以由季节性和/或地区饮食差异来解释。基于包含克鲁格公园有蹄类动物食物时空差异程度的数据矩阵进行的聚类分析揭示了几种不同类别的摄食偏好，这些类别超出了两面浏览器/放牧两分法的范围，例如偏爱任何一种牧草类别的混合喂食者，以及不同浏览器(例如灰斑羚)和不同食草动物(例如水牛)之间统一和混合取食方式之间的空间/季节变化。这些结果突显了对时空变化和饮食连续性敏感的方法的必要性。
Hypotheses to explain diversity among African ungulates focus largely on niche separation along a browser/grazer continuum. However, a number of studies advocate that the browser/grazer distinction insufficiently describes the full extent of dietary variation that occurs within and between taxa. Disparate classification schemes exist because of a lack of uniform and reliable data for many taxa, and failure to incorporate spatio-temporal variations into broader assessments of diet. In this study, we tested predictions for diet and dietary niche separation of African savanna ungulates using stable carbon isotope evidence from faeces for proportions of C-3 (browse) to C-4 (grass) intake among 19 species from the Kruger National Park, South Africa. Dietary predictions from the literature are confirmed in the case of browsers (black rhinoceros Diceros bicornis, giraffe Giraffa camelopardalis, bushbuck Tragelaphus scriptus, kudu Tragelaphus strepsiceros), mixed-feeders (impala Aepyceros melampus, nyala Tragelaphus angasii), and most grazers (white rhinoceros Ceratotherium simum, Burchell's zebra Equus burchellii, warthog Phacochoerus africanus, hippopotamus Hippopotamus amphibius, blue wildebeest Connochaetes taurinus, tsessebe Damaliscus lunatus, waterbuck Kobus ellipsiprymnus). In contrast, several species showed results differing from most expectations derived from the available literature, including eland Taurotragus oryx, steenbok Raphicerus campestris, grey duiker Sylvicapra grimmia, buffalo Syncerus caffer, roan antelope Hippotragus equinus and sable antelope Hippotragus niger. Many of these discrepancies can be accounted for by seasonal and/or regional dietary differences. Cluster analysis based on a data matrix that incorporates the extent of spatio-temporal dietary variation among Kruger Park ungulates reveals several distinct categories of feeding preferences that extend beyond a two-edged browser/grazer dichotomy, such as mixed-feeders with a preference for either forage class, and spatial/seasonal shifts between uniform and mixed-feeding styles among variable browsers (e.g. grey duiker) and variable grazers (e.g. buffalo). These results highlight the need for approaches that are sensitive to spatio-temporal variations and the continuity of diet.