Long- and short-term influence of environment on recruitment in a species with highly delayed maturity

Abstract

Short-term effects of environmental perturbations on various life history traits are reasonably well documented in birds and mammals. But, in the present context of global climate change, there is a need to consider potential long-term effects of natal conditions to better understand and predict the consequences of these changes on population dynamics. The environmental conditions affecting offspring during their early development may determine their lifetime reproductive performance, and therefore the number of recruits produced by a cohort. In this study, we attempted to link recruitment to natal and recent (previous year) conditions in the long-lived black-browed albatross (Thalassarche melanophrys) at Kerguelen Islands. The environmental variability was described using both climatic variables over breeding (sea surface temperature anomaly) and non-breeding grounds (Southern Oscillation index), and variables related to the colony (breeding success and colony size). Immature survival was linked to the breeding success of the colony in the year of birth, which was expected to reflect the average seasonal parental investment. At the cohort level, this initial mortality event may act as a selective filter shaping the number, and presumably the quality (breeding frequency, breeding success probability), of the individuals that recruit into the breeding population. The decision to start breeding was strongly structured by the age of the individuals and adjusted according to recent conditions. An effect of natal conditions was not detected on this parameter, supporting the selection hypothesis. Recruitment, as a whole, was thus influenced by a combination of long- and short-term environmental impacts. Our results highlight the complexity of the influence of environmental factors on such long-lived species, due to the time-lag (associated with a delayed maturity) between the impact of natal conditions on individuals and their repercussion on the breeding population.

Early development, recruitment and life history trajectory in long-lived birds

“…Due to extended pre-breeding period (sometimes longer than 10 years in seabirds; e.g., Jenouvrier et al 2008) and 'insufficient' duration of research projects (relative to the mean longevity in the studied species), most studies have focused on the following traits: post-fledging juvenile survival, survival from independence to recruitment, or recruitment probability (Hario and Rintala 2009;Meathrel and Carey 2007). Longer term consequences of conditions during development have rarely been addressed (Nevoux et al 2010). Naturally, a large number of studies of short-lived birds have also focused on pre-breeding survival and age of first breeding (e.g., Lindén et al 1992;Magrath 1991;Verboven and Visser 1998).…”

“…Depending on the fitness component considered, studies of long-term fitness consequences of early conditions in different species have provided some indication that fitness consequences are either not perceptible before recruitment (post-fledging survival and recruitment probability; Hipfner 1999; Drummond et al 2003), not detectable after recruitment, or no longer detectable after recruitment even if earlier fitness consequences might have been detected (Nevoux et al 2010). Alternatively, van de Pol et al (2006a) found evidence of long-term consequences of the quality of the habitat experienced during growth in Oytercatchers on both survival probability and reproductive success, through the quality of the habitat in which they recruit.…”

“…There is no clear definition of short-or long-lived species; here, long-lived species will be (loosely) referred to as species where a substantial proportion of individuals defer breeding (beyond age 1 year) and where mean reproductive longevity (i.e., after recruitment) may reach 4 years or more (based on estimates available in the literature). In longlived bird species, the extent to which the disadvantage of individuals that are 'frail' at independence is expressed predominantly in terms of higher mortality before recruitment (Braasch et al 2009;Nevoux et al 2010), or persists after recruitment (Reid et al 2003), is still unclear. Here 'frailty' may concern many different phenotypic traits: structural size, body condition, physiological state, morphology, personality, etc.…”

Incorporating ‘recruitment’ in matrix projection models: estimation, parameters, and the influence of model structure

“…Recent advances in the analysis of capturemark-encounter data have provided a robust framework for estimation of and analysis of variation in recruitment while controlling for possible differences in encounter probability and imperfect detection of breeding individuals (Clobert et al 1994 Crespin et al 2006;Jenouvrier et al 2008;Nevoux et al 2010; see Lebreton et al 2009 for a recent review). Recent work by Cam et al (2005) considered the influence of assumptions concerning equivalence of survival probability of pre-breeders and breeders if pre-breeders are unobservable (Clobert et al 1994;Pradel and Lebreton 1999).…”

Effect of extreme sea surface temperature events on the demography of an age-structured albatross population

“…We used an estimate of juvenile survival probability from Nevoux et al [41] assuming that juvenile survival (Sj) was constant over the first 5 years (Sj 0 -5 ¼ Sj 0 -1 *Sj 1 -2 *Sj 2 -3 *Sj 3 -4 *Sj 4 -5 ¼ 0.281). There was no data to estimate annual variation of juvenile survival before recruitment because young birds stay at sea permanently from fledging until first return on land.…”