Severely stressful natal environment does not impact lifetime reproductive success of adult boobies

Although stressful natal conditions are expected to have developmental impacts that prejudice fitness, wild animals sometimes respond to early-life adversity with phenotypic resilience or make life-history adjustments that apparently mitigate fitness penalties. Whether these adjustments enable long-lived animals to completely evade impacts of natural environmental stresses experienced during early development remains uncertain. Analysis of recruits from 18 birth cohorts of the blue-footed booby (Sula nebouxii) showed that El Nino (warm-water) conditions in the natal year did not prejudice annual breeding success, fledgling viability, adult lifespan or lifetime reproductive success. This equivalence of El Nino cohorts was attributed to high average quality due to overrepresentation of young + old parental pairings, known to engender high quality fledglings, and to a possible filtering effect of greater nestling and juvenile mortality, as well as documented life history adjustments. Parents of high-quality or peak reproductive age were not overrepresented in El Nino years. In this long-lived species which faces the worlds most dramatic climatic oscillation, recruits from cohorts that faced the most severe climatic events are fully equivalent to those from cohorts that faced benign conditions, and self-selection of adults for breeding in such conditions may be a key adaptation for achieving this.