SummaryThe Parc National du Banc d’Arguin in Mauritania hosts the largest concentrations of coastal waterbirds along the East Atlantic Flyway. In spite of this importance, a review of the changes in the numbers of waterbirds in the area is lacking since the first complete count in 1980. Here we analysed the seven complete waterbird counts made since then, and the additional yearly counts made in one subunit (Iwik region) since 2003. We present evidence for changes in the community composition of waterbirds over the past four decades. Total waterbird numbers showed a decrease between 1980 and 2017, with only Great White Pelican Pelecanus onocrotalus showing a significant increase in numbers. Five species showed significant declines: Long-tailed Cormorant Phalacrocorax africanus, Red Knot Calidris canutus, Bar-tailed Godwit Limosa lapponica, Eurasian Curlew Numenius arquata, and Western Marsh Harrier Circus aeruginosus. In the remaining species, the variation in numbers between counts was too large, and the number of complete counts too small, for trends to be detected. The yearly counts at Iwik region also showed sharp decreases in the numbers of Red Knot, Bar-tailed Godwit, and Marsh Harrier, but not of Long-tailed Cormorant and Eurasian Curlew. A multivariate analysis revealed a significant change in species composition over time, which was caused mainly by changes in the species depending on the intertidal mudflats for feeding (generally in decline) vs. the species depending on fish and crustaceans in the sublittoral and offshore zones (often showing increases).

中文翻译：

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1980-2017 年毛里塔尼亚 Parc National du Banc d'Arguin 水鸟群落的变化

摘要毛里塔尼亚的 Parc National du Banc d'Arguin 是东大西洋航线沿岸最大的沿海水鸟聚集地。尽管如此重要，但自 1980 年第一次完整计数以来，该地区水鸟数量的变化仍缺乏回顾。在这里，我们分析了自那时以来的七次完整水鸟计数，以及在一个亚单位中进行的额外年度计数（伊维克地区）自 2003 年以来。我们提供了过去四年来水鸟群落组成变化的证据。1980 年至 2017 年间，水鸟总数呈下降趋势，只有大白鹈鹕鹈鹕显示数量显着增加。五个物种出现显着下降： 长尾鸬鹚非洲鲶鱼, 红结鲶鱼, 斑尾塍鹬青柠, 欧亚鹬努门纽斯·阿夸塔和西部沼泽鹞铜绿马戏团。在其余物种中，计数之间的数量变化太大，而完整计数的数量太小，无法检测到趋势。Iwik 地区的年度计数也显示，红结、斑尾塍鹞和沼泽鹞的数量急剧下降，但长尾鸬鹚和欧亚鹬的数量却没有。多变量分析显示物种组成随时间发生显着变化，这主要是由于物种的变化取决于潮间带泥滩的觅食（通常在下降）对比该物种依赖于沿海和近海区域的鱼类和甲壳类动物（通常显示增加）。