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Aim: High‐elevation specialist species are threatened by climate change and habitat loss, and their distributions are becoming increasingly reduced and fragmented. In such a context, dispersal ability is crucial to maintain gene flow among patches of suitable habitat. However, information about dispersal is often lacking for these species, especially for those taxa that are usually considered as good dispersers such as birds. We adopted a landscape genomics approach to investigate dispersal in a climate‐sensitive high‐elevation specialist bird. Our aims were to assess the levels of gene flow within a wide mountain area, and to assess the effects of geographic distance and landscape characteristics on dispersal, by testing the isolation by distance (IBD) hypothesis against the isolation by resistance (IBR) hypothesis. Location: European Alps. Taxon: Montifringilla nivalis. Methods: We sampled individuals from several breeding areas and obtained single nucleotide polymorphism (SNP) data by ddRAD sequencing. We then calculated site‐ and individual level genetic distances and individual inbreeding coefficients. To test IBD versus IBR, we related genetic distances to both geographic distances and different measures of landscape resistance by using maximum likelihood population effects models. Results: Gene flow among breeding areas was partly restricted, and we found support for IBD, indicating that geographic distance limits snowfinch dispersal. Spatial patterns of genetic distances suggested that philopatry strongly contributed to determine the observed IBD. High inbreeding coefficients in several individuals indicated frequent mating among relatives. Main Conclusions: Restricted dispersal and frequent inbreeding within 'sky island' systems can also occur in highly mobile species, because their potential ability to cover very large distances can be counteracted by high philopatry levels that are likely related to high dispersal costs. IBD and philopatry will increasingly hinder snowfinch dispersal among suitable areas within the future more restricted and fragmented breeding range, increasing the risks of local extinctions. [ABSTRACT FROM AUTHOR]

Keywords: distribution; ecological niche; Montifringilla nivalis; mountains; seasonality; snowfinch EN distribution ecological niche Montifringilla nivalis mountains seasonality snowfinch 1 5 5 10/07/22 20220901 NES 220901 Linking organism distribution to climate is key to understanding factors determining species occurrence and evaluating the potential impacts of ongoing climate change. Insufficient considerations of seasonality, data selection and validation lead to biased species-climate relationships in mountain birds However, we are convinced that the reason for such a finding is not an effective niche expansion in the species, but a question of methods - the inclusion of non-representative occurrence records in the analyses of the species' thermal niche -, neglecting crucial facts about the species' ecology. According to the authors, such a wider niche should be related to a "dramatic niche evolution event", leading to a niche expansion dated perhaps 2.6 mya ago, which allowed this species to occupy warmer areas in the western Palearctic, such as southern Europe. [Extracted from the article]

High mountain areas are subject to strong seasonal fluctuations, and species inhabiting these particular environments show a high degree of habitat specialization to cope with extreme abiotic conditions. Estimates of habitat use are influenced by the spatial and seasonal scales at which they are evaluated, so studies at multiple scales are important in order to explore adaptive responses to seasonal environments. In the present study, we assessed habitat use of the White‐winged Snowfinch Montifringilla nivalis subsp. nivalis (henceforth Snowfinch) during breeding and non‐breeding seasons at three different spatial scales (diameters of 100, 250 and 500 m). Although Snowfinches clearly used high‐elevation habitats in both seasons, there was evidence that they are less specific during the non‐breeding period: the variance explained by habitat and topographical factors was lower in winter than in the breeding season. Moreover, our results suggest that the use of habitat is scale‐dependent. This pattern was especially relevant in the breeding season, perhaps because habitat use might be more related to nest‐site selection and specific foraging sites to provide food for nestlings. Snowfinches use high mountain habitats throughout the year, probably as a consequence of physiological and morphological specializations typical of high‐elevation species, but in winter they show a certain flexibility in habitat use. Snowfinches might thus adopt a flexible specialist strategy. This could represent a trade‐off to overcome possible effects on survival, condition and fitness, which can be particularly strong in harsh, unpredictable environments. [ABSTRACT FROM AUTHOR]