Most songbird species show some degree of fidelity to their previous breeding location, especially after successful reproduction. However, species associated with highly dynamic food sources (e.g., outbreaking insects) may have to adopt more flexible strategies. Three species (Tennessee Warbler, Leiothlypis peregrina ; Cape May Warbler, Setophaga tigrina ; and Bay-breasted Warbler, S. castanea ) show strong numerical responses to spruce budworm (Choristoneura fumiferana - SBW) outbreaks. These species, referred to as "budworm-linked warblers", might track SBW larvae through extensive natal dispersal. Then, the superabundance of food during outbreaks would be expected to lead to high breeding productivity which, in turn, should promote breeding site fidelity. Here, we aimed to determine whether budworm-linked warblers were faithful to their previous year's breeding season location and, if so, whether their probability of return was influenced by habitat characteristics such as the density of SBW larvae, stand structure, or landscape structure. We hypothesized that return rate of budworm-linked warblers will be high, as reported in other species of New World warblers, and we predicted that among habitat characteristics, return rate will increase with the density of SBW larvae. We banded 117 budworm-linked warblers (94 % being males) in 75 study plots distributed along a gradient of SBW density and searched for returning individuals within 50 m of their capture sites using song playbacks. Contrary to our hypothesis, resighting rate was very low (0-10.5%). This relative "infidelity" suggests that breeding dispersal of budworm-linked warblers was relatively extensive. Only habitat proportion within an 8-km radius had an important (negative) effect on the probability of resighting Bay-breasted Warbler. Budworm-linked warblers did not exhibit strong site fidelity as adults, but instead performed breeding dispersal movements, presumably to track SBW outbreaks. This strategy may reflect strong spatiotemporal variations in the density SBW larvae.

中文翻译：

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在由云杉芽虫引起的落叶区域边缘，由与芽虫相关的鸣鸟对站点造成不忠

大多数鸣禽物种对它们以前的繁殖场所表现出一定程度的忠诚度，尤其是在成功繁殖之后。但是，与高度动态的食物来源相关的物种（例如，暴发性昆虫）可能必须采用更灵活的策略。三种物种（田纳西州莺，雷奥利皮斯peregrina，开普梅莺，Setophaga tigrina和海湾胸莺，S。castanea）显示出对云杉芽虫（Choristoneura fumiferana-SBW）爆发的强烈数值响应。这些被称为“与bud虫相关的鸣鸟”的物种可能通过广泛的出生扩散来追踪SBW幼虫。然后，预计暴发期间食物的过多会导致高繁殖力，这反过来又可以促进繁殖场所的保真度。这里，我们旨在确定与determine虫相关的鸣鸟是否忠实于其上一年的繁殖季节位置，如果是，则它们的返回概率是否受到栖息地特征（如小生虾幼体密度，林分结构或景观结构）的影响。我们假设与新世界鸣鸟的其他物种有关，与bud虫相关的鸣鸟的返还率很高，并且我们预测在栖息地特征中，返还率将随着SBW幼虫密度的增加而增加。我们在沿着SBW密度梯度分布的75个研究地带中，将117个与蠕虫相关的鸣鸟结合在一起（94％为雄性），并使用歌曲播放搜索了在捕获地点50 m以内的返回个体。与我们的假设相反，复查率很低（0-10.5％）。这种相对的“不忠” 这表明与bud虫相关的鸣虫的繁殖传播相对广泛。只有在8公里半径范围内的栖息地比例对重新看待海湾胸莺的概率具有重要的（负面的）影响。与成虫相关的鸣鸟成年后并未表现出强烈的地点保真度，而是进行了繁殖扩散运动，大概是为了追踪SBW的爆发。此策略可能反映了SBW密度幼虫的强烈时空变化。