This study examined foraging niche partitioning among coexisting species of shorebirds on a sandy beach dominated by a single food type, Horseshoe Crab (Limulus polyphemus) eggs, where use of foraging microhabitats of limited variety is temporarily restricted due to tidal cycle. The major goal of the study was to examine whether co-occurring species differed in selection of foraging microhabitats and use of feeding techniques. Ruddy Turnstone (Arenaria interpres), Red Knot (Calidris canutus), and Sanderling (Calidris alba) foraged significantly more on sand and gravel compared to pools and swash zone, Semipalmated Sandpiper (Calidris pusilla) foraged significantly more on sand and gravel compared to swash zone, but not significantly more compared to pools, while differences in use of microhabitats by Dunlin (Calidris alpina), and Short-billed Dowitcher (Limnodromus griseus) were non-significant. Turnstones used digging and turning stones, and pecking significantly more than probing, Semipalmated Sandpipers used pecking significantly more than probing, while all other species used probing significantly more than pecking. Knots and Sanderlings had the highest level of overlap both in use of microhabitats and foraging techniques, while turnstones and dowitchers had the lowest. Ruddy Turnstones were the only birds that used digging and turning stones to obtain food and these two foraging methods seemed to be the most important variables discriminating turnstones from other co-occurring shorebirds. However, despite the slight differences in use of foraging methods and microhabitats by different species, this study documented weak partitioning among shorebirds, particularly between sandpipers and dowitchers. These results indicate that the short-term absence of clear niche partitioning on a local scale may occur in shorebird communities.

中文翻译：

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通过在单一食物类型环境中迁徙滨鸟进行弱生态位划分

这项研究检查了在以单一食物类型马蹄蟹（鲎）卵为主的沙滩上共存的滨鸟物种之间的觅食生态位分区，由于潮汐周期，暂时限制使用种类有限的觅食微生境。该研究的主要目标是检查共生物种在觅食微生境的选择和饲养技术的使用方面是否存在差异。Ruddy Turnstone (Arenaria interpres)、Red Knot (Calidris canutus) 和 Sanderling (Calidris canutus) 和 Sanderling (Calidris alba) 在沙子和砾石上觅食明显多于水池和冲刷区，半掌鹬 (Calidris pusilla) 在沙子和砾石上觅食明显多于冲刷区区，但与水池相比并没有显着增加，而 Dunlin (Calidris alpina) 在使用微生境方面的差异，和短嘴 Dowitcher (Limnodromus griseus) 不显着。Turnstones使用挖掘和转动石头，啄食明显多于探测，半掌鹬使用啄食明显多于探测，而所有其他物种使用探测明显多于啄食。Knots 和 Sanderlings 在使用微生境和觅食技术方面的重叠程度最高，而转石和 dowitchers 的重叠程度最低。Ruddy Turnstones 是唯一使用挖掘和转动石头来获取食物的鸟类，这两种觅食方法似乎是将 Turnstone 与其他共同出现的水鸟区分开来的最重要变量。然而，尽管不同物种对觅食方法和微栖息地的使用略有不同，但这项研究记录了滨鸟之间的弱分区，特别是在鹬和鹬之间。这些结果表明，滨鸟群落可能会在局部范围内短期缺乏明确的生态位分区。