Spatially nested niche partitioning between syntopic grazers at foraging arena scale within overlapping home ranges.
Spatially nested niche partitioning between syntopic grazers at foraging arena scale within overlapping home ranges.
复制标题
在重叠的家园范围内，在觅食场所规模上，同位食草动物之间的空间嵌套生态位划分。
DOI：
10.1890/es14-00487.1
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发表时间：
2015
期刊：
影响因子：
2.7
通讯作者：
K. Yoganand
中科院分区：
文献类型：
--
作者：
N. Owen‐Smith;Jodie Martin;K. Yoganand
具有相似资源需求的物种之间的生态位分离可以在不同的时空尺度上表达，从觅食地选择的资源成分到栖息地和家域占用，最终是地理分布范围。非洲大型食草动物提出了一个挑战生态位理论，因为多个物种通常重叠空间和植被成分消耗。借助GPS遥测技术，我们调查了两种大型食草动物的空间使用模式，这两种食草动物经常与混合物种聚集在一起。具体而言，我们比较了一个通才放牧与后肠发酵（平原斑马）与类似大小的放牧反刍动物（蓝角马）在西部中部克鲁格国家公园，南非。我们发现，这两个物种的牛群重叠，他们占据的家范围内，但利用空间上不同的觅食舞台持续几天或几个星期内，这些范围内。此外，角马和斑马定居的持续时间不同，在解决，随之而来的单位面积的开发强度，在觅食竞技场内相对于漫游间歇时间花费的比例，并在这些竞技场内的运动速度。特别是，角马群集中在小面积的时间较长，而斑马群使用更多的觅食舞台，但利用他们的短暂时期。这两个物种重叠的栖息地使用，虽然角马更强烈地青睐辉长岩高地和苏打网站呈现短草草坪，而斑马更大的使用面积较高的草覆盖。因此，资源分配主要是通过行为的差异，而不是在家域或栖息地分离的斑块利用觅食竞技场规模。虽然斑马可能已经部分地被排除在角马保持短的草原之外，但这些地点只形成了斑马使用的更广泛范围的一小部分，从而限制了竞争的结果。因此，这种形式的空间嵌套资源分区有助于这两种食草动物的共存，并可能是一种机制，使生态位分离之间的其他物种。
Niche separation among species with similar resource requirements can be expressed at various spatiotemporal scales, from the resource components selected at feeding sites to habitat and home range occupation and ultimately geographic distribution ranges. African large herbivores present a challenge to niche theory because multiple species commonly overlap both spatially and in vegetation components consumed. Aided by GPS telemetry, we investigated the space use patterns of two large grazers that are frequently associated in mixed-species aggregations. Specifically, we compared a generalist grazer with hindgut fermentation (plains zebra) with a similar-sized grazing ruminant (blue wildebeest) in west-central Kruger National Park, South Africa. We found that herds of the two species overlapped substantially in the home ranges that they occupied, but exploited spatially distinct foraging arenas for periods lasting several days or weeks within these ranges. Moreover, wildebeest and zebra differed in duration of settlement, extent of areas occupied during settlement, consequent exploitation intensity per unit area, proportion of time spent within foraging arenas relative to roaming interludes, and movement rates while within these arenas. In particular, wildebeest herds concentrated within small areas for prolonged periods, while zebra herds used more foraging arenas but exploited them for briefer periods. Both species overlapped substantially in habitat use, although wildebeest more strongly favored gabbro uplands and sodic sites presenting short grass lawns while zebra made greater use of areas with a taller grass cover. Hence resource partitioning was expressed mainly through behavioral distinctions in patch exploitation at foraging arena scale rather than in home range or habitat separation. Although zebra may have been partially excluded from the grasslands kept short by wildebeest, these sites formed only a small part of the wider ranges utilized by zebra, thereby restricting the competitive consequences. Hence spatially nested resource partitioning of this form contributes to the coexistence of these two grazers, and may be a mechanism enabling niche separation among other species.