Sample population and colour scoring of tawny owls
Our sample size consisted of 370 individuals from a population in
Uusimaa, southern Finland. The pool of samples included 69 breeding
pairs and their respective offspring, sampled from 2009 until 2021
during the annual monitoring of nest boxes in the area during the
breeding season. Blood was collected from each individual during the
ringing activity, with a sterilized needle and immediately submerged in
SET buffer. Colour phenotyping
was performed according to Karell et al. (2011). Geographic location and
composition of each family (breeding pair and offspring) is available as
supplementary material (Table S1).