Emigration propensity (i.e., the tendency to leave undisturbed patches) is a key life-history trait of organisms in metapopulations with local extinctions and colonizations. Metapopulation models of dispersal evolution typically assume that patch disturbance kills all individuals within the patch, thus causing local extinction. However, individuals may instead be able to leave a patch when it is disturbed, either by fleeing before being killed or simply because the disturbance destroys the patch without causing mortality. This scenario may pertain to a wide range of organisms from horizontally transmitted symbionts, to aquatic insects inhabiting temporary ponds, to vertebrates living in fragmented forests. We generalized a Levins-type metapopulation model of dispersal evolution by adding a new parameter of disturbance escape probability, which incorporates a second source of dispersal into the model: disturbance-induced emigration. We show that disturbance escape expands the domain of metapopulation viability and selects for lower rates of emigration propensity when disturbance rates are high. The fitness gains from disturbance-induced emigration are generally moderate, suggesting that disturbance escape might act more as a complementary dispersal strategy rather than a replacement to emigration propensity, at least for metapopulations that meet the assumptions of the Levins-type model. Yet disturbance-induced emigration may in some circumstances rescue a metapopulation from long-term extinction when the combination of high disturbance rates and low local population growth rates compromises its viability. Further, a metapopulation could persist exclusively by disturbance escape if local carrying capacities are large enough to counterbalance two sources of mortality: mortality driven by disturbance and mortality during dispersal. This study opens two promising research lines: (1) the investigation of disturbance escape in metapopulations of ephemeral habitats with unsaturated populations and non-equilibrium dynamics and (2) the incorporation of information costs to investigate the joint evolution of disturbance escape and emigration propensity.

中文翻译：

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干扰引起的迁徙：一种被忽视的机制，可降低集合种群灭绝风险

迁徙倾向（即留下不受干扰的斑块的倾向）是具有局部灭绝和殖民化的复合种群中生物体的关键生活史特征。散布进化的元种群模型通常假设斑块干扰会杀死斑块内的所有个体，从而导致局部灭绝。然而，个体可能会在受到干扰时离开补丁，要么在被杀死前逃跑，要么仅仅是因为干扰破坏了补丁而不会导致死亡。这种情况可能涉及范围广泛的生物，从水平传播的共生体到栖息在临时池塘的水生昆虫，再到生活在破碎森林中的脊椎动物。我们通过添加新的干扰逃逸概率参数，概括了扩散演化的 Levins 型元种群模型，它将第二个分散来源纳入模型：干扰引起的移民。我们表明，干扰逃逸扩展了种群生存能力的范围，并在干扰率高时选择了较低的移民倾向率。干扰引起的迁徙带来的适应度增益通常是中等的，这表明干扰逃逸可能更多地作为一种补充的分散策略而不是迁徙倾向的替代品，至少对于满足 Levins 型模型假设的元种群而言。然而，在某些情况下，当高干扰率和低当地人口增长率的结合会损害其生存能力时，干扰引起的迁徙可能会从长期灭绝中拯救一个集合种群。更远，如果当地承载能力足够大以抵消两种死亡来源：干扰导致的死亡率和分散过程中的死亡率，一个集合种群可以完全通过干扰逃逸而持续存在。这项研究开辟了两条有前途的研究方向：（1）研究具有不饱和种群和非平衡动态的短暂栖息地的元种群中的干扰逃逸；（2）结合信息成本来调查干扰逃逸和迁徙倾向的联合演化。