Data from: Feather corticosterone reveals that urban great tits experience lower corticosterone exposure than forest individuals during dominance-rank establishment

Data from article published in Conservation Physiology: Feather corticosterone reveals that urban great tits experience lower corticosterone exposure than forest individuals during dominance-rank establishment. Dataset comprises measurements of corticosterone in feathers of urban- and forest-dwelling great tits <em>Parus major</em>. Birds were captured in replicated urban and forest sites in southern Sweden. Two tail feathers (second outermost retrices) were collected from each bird (from a few birds, only one feather was collected), and age (juvenile or adult), sex (female or male) and body mass (in grams) were recorded. Corticosterone in feathers (fCORT) was quantified by ELISA assay (Cayman Chemical, US, product no. 501320), in duplicate, according to the manufacturer instructions. fCORT is corrected for assay dilution and feather length to give fCORT_pg_mm. Refer to the file fCORT_urban_forest_metadata.txt for data definitions.