Data from: Effects of developmental conditions on growth, stress, and telomeres in black-legged kittiwake chicks

Early-life conditions can drive ageing patterns and life history
strategies throughout the lifespan. Certain social, genetic, and
nutritional developmental conditions are more likely to produce
high-quality offspring: those with good likelihood of recruitment and
productivity. Here we call such conditions “favored states” and explore
their relationship with physiological variables during development in a
long-lived seabird, the black-legged kittiwake (Rissa tridactyla). Two
favored states were experimentally generated by manipulation of food
availability and brood size, while hatching order and sex were also
explored as naturally generating favored states. Thus, the favored states
we explored were high food availability, lower levels of sibling
competition, hatching first, and male sex. We tested the effects of
favored developmental conditions on growth, stress, telomere length (a
molecular marker associated with lifespan), and nestling survival.
Generation of favored states through manipulation of both the nutritional
and social environments furthered our understanding of their relative
contributions to development and phenotype: increased food availability
led to larger body size, reduced stress, and higher antioxidant status,
while lower sibling competition (social environment) led to lower telomere
loss and longer telomere lengths in fledglings. Telomere length predicted
nestling survival, and wing growth was also positively correlated with
telomere length, supporting the idea that telomeres may indicate
individual quality, mediated by favored states.