Ryti Randall T, Case Ted J
Department of Biology, C-016 University of California, San Diego, 92093, La Jolla, CA, USA.
Oecologia. 1984 Jun;62(3):401-404. doi: 10.1007/BF00384274.
The spatial patterns and diets of three desert ant species were examined. The results indicate that food competition may account for the spatial arrangement of these species, and that only intraspecific interactions may be required. Each ant species was significantly overdispersed, and the average intraspecific nearest neighbor distances were greater than the interspecific nearest neighbor distances. A test of pairwise spatial arrangment showed that all three species pairs were aggregated interspecifically. The level of the interspecific aggregation was related to the diet similarity of the species. The two species pairs with the lowest diet overlaps were significantly aggregated, and the species pair with the most similar diets was not significantly aggregated. Pairwise dietary overlaps between colonies showed that average intraspecific overlaps were significantly greater than interspecific diet overlaps. Furthermore, the diet overlap was significantly positively correlated to the mean nearest neighbor distance for the three intraspecific and three interspecific comparisons. These data indicate competition for food, especially within species, may be regulating the intercolony distances of these ant species. A computer simulation tested whether only intraspecific territoriality is necessary to produce the observed nearest neighbor distances. A simulation that placed colonies randomly on a patch confirmed that these colonies are intraspecifically overdispersed. By adding intraspecific territoriality, the simulation nearest neighbor distances fit the empirical data reasonably well. Thus interspecific competitive interactions seem unnecessary to account for the spatial arrangement of these species.
对三种沙漠蚂蚁物种的空间格局和食性进行了研究。结果表明，食物竞争可能解释了这些物种的空间分布，并且可能仅需要种内相互作用。每种蚂蚁物种都显著过度分散，种内平均最近邻距离大于种间最近邻距离。成对空间分布测试表明，所有三个物种对在种间都是聚集的。种间聚集程度与物种的食性相似性有关。食性重叠最低的两个物种对显著聚集，而食性最相似的物种对没有显著聚集。蚁群之间的成对食性重叠表明，种内平均重叠显著大于种间食性重叠。此外，在三种种内和三种种间比较中，食性重叠与平均最近邻距离显著正相关。这些数据表明，对食物的竞争，尤其是种内竞争，可能正在调节这些蚂蚁物种的蚁群间距离。通过计算机模拟测试了是否仅种内领地行为就足以产生观察到的最近邻距离。在一个斑块上随机放置蚁群的模拟证实，这些蚁群在种内是过度分散的。通过添加种内领地行为，模拟的最近邻距离与实证数据拟合得相当好。因此，种间竞争相互作用似乎并非解释这些物种空间分布所必需的。
