REPRODUCTION AND IMMUNE HOMEOSTASIS IN A LONG-LIVED SEABIRD, THE NAZCA BOOBY (Sula granti)

The evolution of longevity requires that the marginal investment in self-maintenance at the expense of reproductive effort is favored by realizing a longer reproductive lifespan. This can occur when extrinsic mortality factors (weather, predators, etc.) are less important than intrinsic mortality factors, such as the physiological cost of reproduction. Long-lived pelagic seabirds have low annual reproductive output and prolonged offspring growth periods that are thought to have evolved to accommodate marine resource variability. The life-history theory of senescence predicts that these same taxa should minimize per diem reproductive costs and shift effects of resource variability to the offspring. To address this prediction, we measured parental effort, offspring growth, and one aspect of self-maintenance (serum immunoglobulin G concentration [IgG]) in a long-lived pelagic seabird, the Nazca Booby (Sula granti). We collected data on 38 families in the 2002–2003 breeding season on Isla Espanola, G...