Data for: Heritability and parental effects in telomere length in a color polymorphic long-lived bird

Telomere length, an indicator of senescence, has been shown to be heritable but can also be affected by environmental factors, like parental effects. Investigating heritability as well as parental effects and rearing environment can help us to understand the factors affecting offspring telomeres. Moreover, how phenotypic parental traits linked with fitness can impact offspring telomere length is still unclear. A phenotypic marker closely associated with physiological traits and fitness is melanin-based color polymorphism, which in tawny owl (Strix aluco) is highly heritable and strongly associated with adult telomere shortening and survival.  We studied narrow-sense heritability (h2) of telomere length (RTL), as well as the impact of parental age and color morph and their interaction on offspring telomere length. Offspring RTL at fledging was strongly positively correlated with both mother and father RTL at breeding. Offspring RTL was also negatively associated with father age, suggesti...