Data_Variation in wing morphology is related to breeding environment in a high-elevation specialist bird

This database include morphological and environmental data used in paper 'Variation in wing morphology is related to breeding environment in a high-elevation specialist bird?', Journal of Avian Biology (DOI 10.1111/jav.03007). Measured birds were captured during the breeding period with mist-nets and spring traps at 55 different sites within 10 study areas in the central-eastern Italian Alps during spring/summer 2021. Primary feathers lengths (P9-P1) were measured by a metal ruler (± 0.5 mm). Age and sex were determined according to Svensson (1992) and Demongin (2016). At each capture site, percentage cover of vegetation categories within a 100-m radius was visually estimated in the field to the nearest 5%, and variables estimated to cover less than 5% of the plot were assigned a 1% cover value.