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首页> 外文期刊>San Francisco Estuary and Watershed Science >Abundance, Species Richness, and Reproductive Success of Tidal Marsh Birds at China Camp State Park, Marin County, California
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Abundance, Species Richness, and Reproductive Success of Tidal Marsh Birds at China Camp State Park, Marin County, California

机译：加州马林县中国营地州立公园潮汐沼泽鸟的丰度，物种丰富度和繁殖成功

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Extensive habitat loss and degradation have resulted in decreases in populations of tidal marsh breeding birds in the San Francisco Estuary in the past 150 years. We conducted point count surveys and nest monitoring in tidal marsh habitat at China Camp State Park from 1996 through 2007 to assess bird abundance, species richness and reproductive success over time. We found overall species richness at China Camp to be significantly lower than that of other San Pablo Bay tidal marshes, but also to be increasing during the study period. We present relative density indices and confirm breeding for three focal species that are of conservation concern: San Pablo song sparrow (Melospiza melodia samuelis), California black rail (Laterallus jamaicensis coturniculus), and California clapper rail (Rallus longirostris obsoletus). Song sparrows were observed at higher densities at China Camp than at other San Pablo Bay sites. There was no apparent trend in song sparrow density during the study period at China Camp, in contrast with the rest of San Pablo Bay, which displayed a significant decline. We determined song sparrow nest survival probability using the method described by Mayfield (1975) and found that nest survival at China Camp varied markedly among years, from >30% in 1996 to 6% in 2006, with no discernible trend. The main causes of nest failure were predation and tidal flooding. Song sparrow nests were found predominantly in gumplant (Grindelia stricta) and pickleweed (Sarcocornia pacifica) and less commonly in saltgrass (Distichlis spicata). Clapper rails nested exclusively in pickleweed and black rail nests were found mainly in gumplant and less commonly in saltgrass. China Camp’s expansive ancient marsh supports endemic and bird species of conservation concern, while serving as a reference site for tidal marsh studies in San Francisco Bay. The long-term monitoring of tidal marsh bird breeding parameters at China Camp has the potential to provide early detection of declining population trends before local populations become imperiled.
机译：在过去的150年中，栖息地的大量丧失和退化导致旧金山河口的潮汐沼泽繁殖鸟类的数量减少。从1996年到2007年，我们在中国营州立公园的潮汐沼泽栖息地进行了点计数调查和巢监测，以评估鸟类的丰富度，物种丰富度和繁殖成功的时间。我们发现中国营地的总体物种丰富度显着低于其他圣巴勃罗湾潮汐沼泽，但在研究期间也正在增加。我们提出了相对密度指数并确认了三个需要保护的重点物种的繁殖：圣巴勃罗歌雀（Melospiza melodia samuelis），加利福尼亚黑杆（Laterallus jamaicensis coturniculus）和加利福尼亚拍板杆（Rallus longirostris obsoletus）。在中国营地观察到的松雀密度高于其他圣帕勃罗湾遗址。在研究期间，中国营地的麻雀密度没有明显的趋势，而圣巴勃罗湾其他地区则明显下降。我们使用Mayfield（1975）所描述的方法确定了歌麻雀的巢生存率，发现China Camp的巢生存年数显着变化，从1996年的> 30％到2006年的6％，没有明显的趋势。筑巢失败的主要原因是掠食和潮汐泛滥。松雀巢主要在口香糖（Grindelia stricta）和泡菜（Sarcocornia pacifica）中发现，而在香茅（Distichlis spicata）中则较少见。仅在腌菜中嵌套的拍板导轨和黑色的导轨嵌套主要在口香糖中发现，在草皮中较少见。 China Camp广阔的古代沼泽支持着当地物种和鸟类的保护，同时也为旧金山湾的潮汐沼泽研究提供了参考。在中国营地对潮汐沼泽鸟类的繁殖参数进行长期监测，有可能在当地人口陷入困境之前提早发现种群下降的趋势。

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