Habitat preferences of wintering shorebirds in a temporally changing environment: Western sandpipers in the San Francisco Bay estuary
Habitat preferences of wintering shorebirds in a temporally changing environment: Western sandpipers in the San Francisco Bay estuary
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DOI：
10.2307/4089023
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发表时间：
1995-10
期刊：
影响因子：
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通讯作者：
S. Warnock;J. Takekawa
中科院分区：
文献类型：
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作者：
S. Warnock;J. Takekawa
-我们在冬季和春季在两个尺度上研究了旧金山湾河口 106 种无线电标记的西部鹬 (Calidris mauri) 的栖息地偏好：比较其栖息地范围内的栖息地与研究区域中可用栖息地的比例（二阶选择），以及比较不同栖息地中无线电位置的比例与其在栖息地范围内的可用性（三阶选择）。随着栖息地可用性的暂时变化，每日和季节性栖息地偏好存在显着差异。在二级选择下，西部鹬在冬季低潮时偏好潮汐沼泽和泥滩，在高潮时偏好盐塘堤坝。在三阶选择下，低潮时偏好盐塘堤和泥滩，高潮时偏好盐塘堤。春季，它们最喜欢的栖息地是排水和潮汐盐池以及涨潮时的季节性湿地。退潮时，它们的首选栖息地是潮汐泥沼和潮汐盐池。在这两个季节，盐沼平原都是最不受欢迎的栖息地。成鱼在使用低潮栖息地方面比幼鱼更具选择性，但盐池堤坝是两者最喜欢的栖息地。当使用不同的栖息地可用性和使用估计时，栖息地偏好差异很大。如果将泥滩栖息地测量为沿着潮汐线的线性觅食区域，那么对这些栖息地的偏好从第二到第一增加。当从无线电位置而不是家庭范围估计二阶选择时，所得的组成与三阶选择相似。我们的研究结果表明，为了濒危物种的利益而恢复盐沼的区域保护计划必须考虑失去人工盐池栖息地的影响，这对鹬在当地很重要。 1994 年 10 月 14 日收稿，1995 年 2 月 22 日接受。旧金山湾是北美太平洋沿岸最大的河口之一（Conomos 1979），但从 1850 年开始，海湾的大部分天然湿地都被堤坝和改造用于农业、城市和工业目的（Ver Planck 1958）。尽管在过去的 150 年里大部分自然栖息地已经消失，河口仍然支持着许多野生动物物种，包括美国西海岸最大、最多样化的越冬和迁徙滨鸟群落（J. Kjelmyr、G. W. Page、W. D. Shuford 和 L. E. Stenzel，未发表的 1991 年报告） 尽管旧金山一号地址很重要：EECB/186， 1000 Valley Road，内华达大学，里诺，内华达州 89512，美国。 2 目前地址：美国国家生物服务局，加州太平洋科学中心，旧金山湾河口现场站，邮政信箱Box 2012，瓦列霍，加利福尼亚州 94592，美国。海湾河口滨鸟的越冬生态学研究很少（Recher 1966，Kelly 和 Cogswell 1979，Holway 1990）。人们对冬季鸻鹬鸟栖息地的选择以及它们的栖息地偏好如何随时间变化知之甚少。因此，湿地的进一步改造可能在多大程度上改变河口鸻鹬鸟类的分布和数量尚不清楚。我们描述了 1991-1992 年冬季和春季南旧金山湾放射性标记的西部鹬 (Calidris mauri) 的栖息地偏好。我们在两个选择水平上考察偏好（Johnson 1980）：（1）与整个研究区域的可用栖息地相比，使用西部鹬栖息地内的栖息地（二阶选择）； (2) 将无线电位置确定的栖息地利用与居住范围内可用的栖息地进行比较（三阶选择）。此外，我们还解决了测量动态生态系统中栖息地可用性的固有困难，以及
-We examined habitat preferences of 106 radio-marked Western Sandpipers (Calidris mauri) in the San Francisco Bay estuary during winter and spring at two scales: comparing proportions of habitats in their home range with habitats available in the study area (second-order selection), and comparing proportions of radio locations in different habitats with their availability in the home range (third-order selection). Daily and seasonal habitat preferences differed significantly as habitat availability changed temporally. Under second-order selection, Western Sandpipers preferred tidal sloughs and mud flats on winter low tides, and salt-pond levees at high tides. They preferred salt-pond levees and mud flats at low tides, and salt-pond levees at high tides under third-order selection. During the spring, their preferred habitats were drained and tidal salt ponds, and seasonal wetlands at high tide. At low tide, their preferred habitats were tidal sloughs and tidal salt ponds. Salt-marsh plains were the least preferred habitats during both seasons. Adults were more selective than juveniles in use of low tide habitats, but salt-pond levees were the most preferred habitats for both. Habitat preferences varied considerably when different estimates of habitat availability and use were used. If mud-flat habitats were measured as linear foraging areas along the tide line, the preference for those habitats increased from second to first. When secondorder selection was estimated from radio locations rather than home ranges, the resulting composition was similar to third-order selection. Our results suggest that regional conservation plans that restore salt marshes for the benefit of endangered species must consider the effects of losing artificial salt-pond habitats, which are locally important for sandpipers. Received 14 October 1994, accepted 22 February 1995. SAN FRANCISCO BAY is one of the largest estuaries on the Pacific coast of North America (Conomos 1979), but beginning in 1850 most of the natural wetlands of the bay were diked and altered for agricultural, urban, and industrial purposes (Ver Planck 1958). Although much of the natural habitat has been lost over the past 150 years, the estuary still supports many species of wildlife, including the largest and most diverse community of wintering and migrating shorebirds on the western coast of the United States (J. Kjelmyr, G. W. Page, W. D. Shuford, and L. E. Stenzel, unpubl. 1991 report) Despite the importance of the San Francisco I Present address: EECB/186, 1000 Valley Road, University of Nevada, Reno, Nevada 89512, USA. 2 Present address: U.S. National Biological Service, California Pacific Science Center, San Francisco Bay Estuary Field Station, P.O. Box 2012, Vallejo, California 94592, USA. Bay estuary for shorebirds, few studies have been conducted on their wintering ecology (Recher 1966, Kelly and Cogswell 1979, Holway 1990). Little is known about selection of habitats by shorebirds during the winter, or how their habitat preferences change temporally. Thus, the extent to which further modification of wetlands may change the distribution and abundance of shorebirds in the estuary is not known. We describe habitat preferences of radiomarked Western Sandpipers (Calidris mauri) in South San Francisco Bay during winter and spring, 1991-1992. We examine preferences at two levels of selection (Johnson 1980): (1) use of habitats within home ranges of Western Sandpipers compared to available habitat in the overall study area (second-order selection); and (2) comparison of habitat use determined from radio locations to habitats available in home ranges (third-order selection). In addition, we address the inherent difficulties of measuring habitat availability in dynamic ecosystems, and