MaleForehead_Natalconditions.JMP.csv

Data were collected between 1993 and 2021 during a long-term study of pied flycatchers breeding in nest-boxes in central Spain (La Hiruela, 41°04' N, 3°27' W). Because of limited field effort in 2002 and 2003, these years were excluded from the analyses. The population occupies an old deciduous forest dominated by oaks (<i>Quercus pyrenaica</i>) and a nearby (1.1 km) mixed coniferous plantation dominated by <i>Pinus sylvestris </i>(see Camacho et al. 2015 for a description of the study area). Breeding seasons last from late April to mid-July. Nest-boxes (n=237) were inspected every 2-3 days to record laying date (date of the first laid egg), clutch size, number of hatchlings, and number of fledglings. Breeding individuals were captured using a nest-box trap, individually marked with color (only males) and metal (males and females) bands, measured for tarsus length (±0.05 mm), weighed (±0.1 g), and aged as either one-year old or older following previously published criteria.