Wetlands in southern Ontario are at risk of degradation and alteration due to human activities. This is a concern because wetlands provide essential habitat for species from a range of taxa, such as birds and anurans (frogs and toads). One wetland-dwelling species whose decline may be linked to loss of wetland wildlife habitat is the muskrat (Ondatra zibethicus). The decline of muskrats may also be linked to declines of other species because muskrats engage in activities that could support taxa such as birds and anurans by increasing habitat heterogeneity. We investigated whether bird and anuran species richness is related to muskrat density or if it is better predicted by land cover variables that describe the wetland and surrounding area at 30 coastal wetlands on Lake Ontario. We estimated bird and anuran species richness using data from the Great Lakes Marsh Monitoring Program and the Great Lakes Coastal Wetland Monitoring Program, and muskrat density based on muskrat house counts. Our results suggest that muskrat activity did not predict richness of anurans or birds overall; however, it did predict richness for the subset of birds that nest in emergent aquatic vegetation. Our results indicate that muskrat abundance in emergent marshes may increase habitat quality for birds that nest in emergent vegetation but may not have a measurable effect on anuran diversity in these same wetlands.

由于人类活动，安大略省南部的湿地面临退化和改变的风险。这是一个令人担忧的问题，因为湿地为鸟类和无尾动物（青蛙和蟾蜍）等一系列类群的物种提供了必要的栖息地。麝香鼠 ( Ondatra zibethicus )是一种湿地物种，其数量下降可能与湿地野生动物栖息地的丧失有关。麝香鼠的减少也可能与其他物种的减少有关，因为麝香鼠从事的活动可以通过增加栖息地异质性来支持鸟类和无尾目动物等类群。我们调查了鸟类和无尾动物物种丰富度是否与麝香鼠密度相关，或者是否可以通过描述安大略湖 30 个沿海湿地湿地及周边地区的土地覆盖变量来更好地预测。我们利用五大湖沼泽监测计划和五大湖沿海湿地监测计划的数据估算了鸟类和无尾动物物种的丰富度，并根据麝香鼠的房屋数量估算了麝香鼠的密度。我们的结果表明，麝香鼠的活动并不能预测无尾动物或鸟类的总体丰富度。然而，它确实预测了在新兴水生植被中筑巢的鸟类子集的丰富度。我们的结果表明，新兴沼泽中麝香鼠的丰富度可能会提高在新兴植被中筑巢的鸟类的栖息地质量，但可能不会对这些湿地中的无尾动物多样性产生可测量的影响。