Temporal landscape genetic data indicate an ongoing disruption of gene flow in a relict bird species

摘要

A major concern in conservation biology today is the loss of genetic diversity in structured populations, which is often a consequence of habitat contraction and restricted gene flow over time. These dynamic biological processes require monitoring with temporal environmental and landscape genetic data. We compared the spatial genetic variation of a relict, umbrella species, the capercaillie (Tetrao urogallus), in two different demographic periods, as represented by older museum specimens (1960-1990) and recent non-invasive samples (2011-2015) collected from the Carpathian Mountains, where habitat connectivity has dramatically decreased in the past decade. Using a combination of species distribution modelling and spatial genetic inference, we analysed how climatic and environmental constraints shaped population structures of the species. Environmental and climate niche models confirmed that relict Carpathian capercaillie populations are temperature sensitive, and they occur in a narrow range of mountain forest habitats at the highest altitudes. We found that the environmental and climatic constraints led to genetically isolated populations, but we also detected clusters that did not match relatively interrupted areas of niche habitats. We observed a similar disruption of gene flow in both periods; however, a stronger signal of genetic structuring in recent samples indicated that the processes negatively affecting connectivity are ongoing. The effective population size of the Carpathian population has declined in recent years, but it has been low for at least the last five decades in the Western Carpathians. This study demonstrates the importance of temporal ecological and genetic data as an effective warning tool for the conservation and management of wildlife species.