Do group dynamics affect colour morph clines during a range shift?

Species exhibiting colour-polymorphism are thought to have an ecological advantage at the landscape scale, because spatial segregation of alternatively-adapted ecotypes into diverse habitats can increase the total species’ niche breadth and thus confer greater geographic range size. However, morph frequencies are also influenced by intra-populational processes such as frequency- or density-dependent social interactions. To identify how social feedback may affect clinal variation in morph frequencies, we investigated reciprocal interactions between morph-specific thermal tolerance, local climatic conditions, and social environments, in the context of a colour-morph frequency cline associated with a recent range expansion in blue-tailed damselflies (Ischnura elegans) in Sweden. Cold tolerances of gynochromes (female-like female morph) were positively correlated with local gynochrome frequencies, suggesting a positive frequency-dependent fitness benefit of being common. In contrast, androc...

具有颜色多态性（colour-polymorphism）的物种被认为在景观尺度上具备生态优势，原因在于适应不同环境的生态型（ecotype）通过空间分隔占据多样生境，可拓宽物种整体的生态位宽度（niche breadth），进而赋予其更大的地理分布范围。然而，种群内部过程同样会影响形态型（morph）频率，例如频率依赖（frequency-dependent）或密度依赖（density-dependent）的社会互动。为明确社会反馈如何作用于形态型频率的渐变变异（clinal variation），我们以瑞典境内近期发生分布扩张（range expansion）的蓝尾豆娘（Ischnura elegans）为研究对象，围绕其颜色形态型频率渐变带（colour-morph frequency cline），探究了形态特异性热耐受性（morph-specific thermal tolerance）、局地气候条件（local climatic conditions）与社会环境（social environments）之间的相互作用。研究发现，雌色型（gynochrome）的耐寒性与当地雌色型频率呈正相关，表明种群占比更高的形态型可获得正频率依赖的适合度收益。与之相反，雄色型（androc...）