Knudsen Thøger Engelund, MacKenzie Brian R, Thygesen Uffe Høgsbro, Mariani Patrizio
National Institute of Aquatic Resources - DTU Aqua, Technical University of Denmark, Building 201, Anker Engelundsvej, 2800, Kgs. Lyngby, Denmark.
Department of Applied Mathematics and Computer Science - DTU Compute, Technical University of Denmark, Building 303B, Matematiktorvet, 2800, Kgs. Lyngby, Denmark.
Mov Ecol. 2025 Jun 13;13(1):43. doi: 10.1186/s40462-025-00564-3.
The conditions regulating long distance migrations of large animal groups remain elusive in ecology. It has been suggested that individual interactions, environmental constraints and social dynamics play a major role in group formation and migration processes. The challenge is in how to incorporate those dynamics within a framework that reproduces observed dynamics and allows to investigate conditions for the persistence or collapse of migrations. We introduce a general model for seasonally migratory populations where individuals belong to separate contingents each representing a specific migration strategy. Contingents mix during the reproductive phase while the feeding migration is regulated by group formation and social learning. The model is solved numerically, illustrating key factors shaping population dynamics and migration. We identify non-linear critical thresholds in social learning regulating successful migrations. We also determine the conditions for similar thresholds in the behavioural adaptation of the species. This indicates that migration strategies could disappear from a population given social and environmental constraints. These results offer new perspectives on animal conservation and environmental management. Indeed, the removal of individual migrants may have long term consequences for the migratory strategies of the population, possibly leading to irreversible shifts in social behaviour and disruptions of local communities.
在生态学中，调节大型动物群体远距离迁徙的条件仍然难以捉摸。有人提出，个体间的相互作用、环境限制和社会动态在群体形成和迁徙过程中起着重要作用。挑战在于如何将这些动态纳入一个框架，该框架既能再现观察到的动态，又能用于研究迁徙持续或崩溃的条件。我们引入了一个适用于季节性迁徙种群的通用模型，其中个体属于不同的群体，每个群体代表一种特定的迁徙策略。群体在繁殖阶段混合，而觅食迁徙则受群体形成和社会学习的调节。该模型通过数值求解，展示了塑造种群动态和迁徙的关键因素。我们确定了社会学习中调节成功迁徙的非线性临界阈值。我们还确定了物种行为适应中类似阈值的条件。这表明，在社会和环境限制下，迁徙策略可能会从种群中消失。这些结果为动物保护和环境管理提供了新的视角。的确，个体迁徙者的移除可能会对种群的迁徙策略产生长期影响，可能导致社会行为的不可逆转转变和当地群落的破坏。
