Energy, growth and oxidative stress in Leach’s storm-petrels
Throughout their lifespan, organisms must invest energy into growth, self-maintenance, and reproduction. However, energy is limiting, so trade-offs exist when individuals allocate more to one system while neglecting another. When food is scarce during development, growth is often limited, but compensatory or “catch-up” growth allows individuals to recover from stunted growth when food is available. However, these rapid growth periods often come at a fitness cost, one of which may be advanced cellular aging as seen through shortened telomeres and oxidative stress. Telomeres protectively cap the ends of chromosomes and act as a main mechanism driving cellular senescence. Their susceptibility to cellular insults allows them to serve as a biomarker of aging, and telomere maintenance is highly related to organismal longevity. We experimentally manipulated food availability to determine the effects of food restriction and subsequent growth on cellular aging in a natural breeding colony of Leach’s Storm-Petrels (Hydrobates leucorhous) during the nestling stage. Morphometric data indicated periods of rapid catch-up growth for nutritionally restricted chicks. These individuals also showed increased oxidative stress and reduced telomere length, indicating a fitness cost to either the nutritional restriction, the rapid growth, or both. This study provides the first mechanistic links between experimentally manipulated nutritional conditions on growth, oxidative stress, and telomere dynamics in a natural population and presents a more complete picture of the consequences of adverse nutritional conditions on fitness.