PDF(Pubmed)
Abstract：
The outcomes of species interactions can vary by life stage, year, and surrounding environmental conditions. Amphibian species are expected to compete most strongly during their tadpole stage when they exist in the highest densities. Changes in arrival timing, surrounding aquatic communities, and yearly conditions could all affect the outcome of larval competition. In Long Point, Ontario, the Fowler\'s toad (Anaxyrus fowleri) is at the northern edge of its range and overlaps with the more common American toad (Anaxyrus americanus). Both species breed in ponds that encounter high inter-annual variation. To determine whether these species compete strongly, and if this effect was replicated across multiple years, we raised both species as tadpoles together and, apart, in mesocosms in 2018 and 2021. We measured survivorship to, weight at, and time to metamorphosis for both species in both years. We determined that the presence of American toad tadpoles consistently had a detrimental effect on Fowler\'s toad tadpoles, even though this effect presented itself differently across years. Our study suggests that competitive exclusion by American toads could be occurring at the edge of the Fowler\'s toad\'s range. This study further demonstrates the importance of studying communities across multiple years to understand the full scope of species interactions.
摘要：
物种相互作用的结果可能因生命阶段而异，Year,和周围环境条件。当两栖动物以最高密度存在时，预计它们在t阶段的竞争最激烈。到达时间的变化，周围的水生群落，每年的情况都会影响幼虫竞争的结果。在长点，安大略省,Fowler的蟾蜍（Anaxyrusfowleri）位于其范围的北部边缘，与更常见的美国蟾蜍（Anaxyrusamericanus）重叠。这两个物种都在遇到高年际变异的池塘中繁殖。为了确定这些物种是否竞争激烈，如果这种效应在多年内复制，我们把这两个物种都当作t一起饲养，除了,在2018年和2021年的mesocoss中。我们测量了存活率，体重，以及两个物种在两年内变态的时间。我们确定美国蟾蜍t的存在一直对Fowler的蟾蜍t产生不利影响，即使这种影响在不同的年份中表现得不同。我们的研究表明，美国蟾蜍的竞争性排斥可能发生在福勒蟾蜍范围的边缘。这项研究进一步证明了研究多年社区的重要性，以了解物种相互作用的全部范围。
