Does Population Size Drive Changes in Transatlantic Vagrancy for Gulls? A Study of Seven North Atlantic Species
Does Population Size Drive Changes in Transatlantic Vagrancy for Gulls? A Study of Seven North Atlantic Species
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DOI：
10.3389/fevo.2022.850577
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发表时间：
2022-04-25
影响因子：
3
通讯作者：
Veit, Richard R.
中科院分区：
文献类型：
--
作者：
Acosta Alamo, Marlen;Manne, Lisa L.;Veit, Richard R.
欧洲鸥 Chroicocephalus rodibundus、Larus canus 和 L. graellsii 已扩散至北美，C. rodibundus 和 L. graellsii 已繁殖或试图繁殖。北美海鸥 L. delawarensis、Leucophaeus atricilla、Leucophaeus pipixcan 和 Chroicocephalus philadelphia 已传播到欧洲，但尚未发生非杂交对的成功繁殖。我们假设，随着海鸥种群规模的增加，探索潜在新繁殖地的鸟类数量也会增加。为了检验我们的假设，我们使用广义线性模型将跨大西洋流浪者的数量与前一年的人口规模进行了比较。我们发现越来越多的跨大西洋流浪者双向流动，这表明流浪不是强风驱动的随机现象，也不是反向迁移引起的。人口规模预测了七个物种中四个物种的跨大西洋流浪现象。然而，我们关于人口规模的增加会导致流浪现象增加的假设仅在其中两个例子中得到支持。我们进一步研究了北美 L. delawarensis 的亚种群，并检验了我们对每个亚种群的假设。我们发现这些数据部分支持我们的假设。即使在一个物种内，我们也观察到流浪与种群规模之间的多种关系。我们的结果表明，在某些情况下，来源人口规模的规模或趋势显然是流浪的驱动因素，但其他因素也必须发挥重要作用。随着人类活动的持续发展，优质栖息地之间的距离越来越远，我们必须继续调查流浪的所有驱动因素，因为一个物种的持久性可能很大程度上取决于其最长距离的分散者。
European gulls Chroicocephalus ridibundus, Larus canus, and L. graellsii have dispersed to North America and C. ridibundus and L. graellsii have bred or attempted to breed. North American gulls L. delawarensis, Leucophaeus atricilla, Leucophaeus pipixcan, and Chroicocephalus philadelphia have dispersed to Europe, although no successful breeding by non-hybrid pairs has yet occurred. We hypothesized that as gull population sizes increase, the number of birds exploring potential new breeding sites also increases. To test our hypothesis, we compared the number of transatlantic vagrants to the population size on the previous year using generalized linear models. We found an increasing number of transatlantic vagrants moving in both directions, which suggests that vagrancy is not a random phenomenon driven by strong winds nor caused by reverse migration. Population size predicted transatlantic vagrancy in four of the seven species. However, our hypothesis that increases in population size drive increases in vagrancy was only supported in two of these instances. We further looked at sub-populations of L. delawarensis in North America and tested our hypothesis for each subpopulation. We found partial support for our hypothesis for these data. Even within one species, we observed multiple relationships between vagrancy and population size. Our results showed that size or trend in source population size-in some circumstances-is clearly a driver of vagrancy, but other factors must play an important role too. As anthropogenic development continues, and high-quality habitats become farther apart, it is important that we continue to investigate all drivers of vagrancy because the persistence of a species may depend crucially on its longest-distance dispersers.