To breed or not to breed: a seabird's response to extreme climatic events

Abstract

Intermittent breeding is an important lifehistory strategy that has rarely been quantified in the wild and for which drivers remain unclear. It may be the result of a trade-off between survival and reproduction, with individuals skipping breeding when breeding conditions are below a certain threshold. Heterogeneity in individual quality can also lead to heterogeneity in intermittent breeding. We modelled survival, recruitment and breeding probability of the red-footed booby (Sula sula), using a 19 year mark -recapture dataset involving more than 11 000 birds. We showed that skipping breeding was more likely in El-Niñ o years, correlated with an increase in the local sea surface temperature, supporting the hypothesis that it may be partly an adaptive strategy of birds to face the trade-off between survival and reproduction owing to environmental constraints. We also showed that the age-specific probability of first breeding attempt was synchronized among different age-classes and higher in El-Niñ o years. This result suggested that pre-breeders may benefit from lowered competition with experienced breeders in years of high skipping probabilities.

Apparent survival of adult Leach’s Storm-petrels (Oceanodroma leucorhoa) breeding on Bon Portage Island, Nova Scotia

“…Seabirds are usually characterized as having high adult survival probabilities that should be quite resilient to environmental variability. Maintenance of high survival probabilities is possible in part because they can reduce reproductive effort, or even skip breeding in unfavorable years to focus instead on selfpreservation (Cubaynes et al 2011, Zabala et al 2011. However, given their slow reproductive rates, even minor reductions in adult survival can have pronounced effects on seabird populations (Wooller et al 1992), which are slow to recover after episodes of high adult mortality (Weimerskirch and Jouventin 1987).…”

“…For long-lived seabirds, adult survival is one of the most important demographic traits for maintaining viable populations and should remain relatively high and constant despite natural environmental variability (Clobert and Lebreton 1991, Erikstad et al 1998, Cubaynes et al 2011. Therefore, variability in seabird population size is often associated with reproductive output, because breeding adults are able to reallocate investment from reproductive effort to self-maintenance when conditions, e.g., weather, food supply, are poor (Erikstad et al 1998, Cubaynes et al 2011, Hovinen et al 2014.…”

“…Therefore, variability in seabird population size is often associated with reproductive output, because breeding adults are able to reallocate investment from reproductive effort to self-maintenance when conditions, e.g., weather, food supply, are poor (Erikstad et al 1998, Cubaynes et al 2011, Hovinen et al 2014. Conversely, slow reproductive rates and high breeding site fidelity of seabirds mean that their populations are sensitive to even minor changes in adult survival; consistently low or highly variable survival probabilities are signs that a population is under stress and at a greater risk of rapid decline (Weimerskirch andJouventin 1987, Wooller et al 1992).…”

Nest fidelity is driven by multi-scale information in a long-lived seabird

“…Nevertheless, temporal variation in environmental quality is another important, universal source of variation in annual reproductive success and empirical evidence suggests that some organisms are able to process predictive information about the quality of the breeding season and respond to this information. Such mechanisms have been described in relation to the survival cost of reproduction in long-lived animals, whereby individuals can delay first breeding or skip reproduction in bad years to maximize their lifetime reproductive success [20,21].…”

To breed or not to breed: endocrine response to mercury contamination by an Arctic seabird

“…Long-lived birds often skip breeding when foraging conditions are poor, modulating their reproductive effort according to environmental conditions [14]. The present situation in the Arctic is of concern: mercury levels in seabirds are increasing [15] and if combined with rapid climate change, we are facing a worst-case scenario [16].…”