Linking demographic processes and foraging ecology in wandering albatross—Conservation implications

Abstract

Population dynamics and foraging ecology are two fields of the population ecology that are generally studied separately. Yet, foraging determines allocation processes and therefore demography. Studies on wandering albatrosses Diomedea exulans over the past 50 years have contributed to better understand the links between population dynamics and foraging ecology. This article reviews how these two facets of population ecology have been combined to better understand ecological processes, but also have contributed fundamentally for the conservation of this long‐lived threatened species.Wandering albatross research has combined a 50‐year long‐term study of marked individuals with two decades of tracking studies that have been initiated on this species, favoured by its large size and tameness.At all stages of their life history, the body mass of individuals plays a central role in allocation processes, in particular in influencing adult and juvenile survival, decisions to recruit into the population or to invest into provisioning the offspring or into maintenance.Strong age‐related variations in demographic parameters are observed and are linked to age‐related differences in foraging distribution and efficiency. Marked sex‐specific differences in foraging distribution, foraging efficiency and changes in mass over lifetime are directly related to the strong sex‐specific investment in breeding and survival trajectories of the two sexes, with body mass playing a pivotal role especially in males.Long‐term study has allowed determining the sex‐specific and age‐specific demographic causes of population decline, and the tracking studies have been able to derive where and how these impacts occur, in particular the role of long‐line fisheries.

A framework for mapping the distribution of seabirds by integrating tracking, demography and phenology

“…Indeed, juveniles of several species of albatrosses and petrels disperse more widely and more to the north of the species range, often to less productive waters than adults (Riotte‐Lambert & Weimerskirch, ; Weimerskirch et al, ). Similarly, the often substantial individual variability among juvenile and immature birds can be difficult to capture with limited tracking effort (Clay, ), but as immatures age, their distributions become increasingly similar to those of adults (de Grissac, Börger, Guitteaud, & Weimerskirch, ; Weimerskirch, ). Accounting for all life‐history stages in distribution maps may be even more relevant for near‐obligate biennial breeders such as the great Diomedea spp., sooty Phoebetria spp.…”

Sex‐biased survival contributes to population decline in a long‐lived seabird, the Magellanic Penguin

“…Survival rates increase dramatically between fledglings and 1‐yr‐olds in Magellanic Penguins (this study). In Wandering Albatross, the foraging skills of fledglings improve rapidly over the first few months at sea, after which they are comparable to those of adults (Weimerskirch ). We found that survival decreased again for individuals ≥19 yr of age, potentially because of senescence‐related reductions in foraging efficiency (e.g., Zimmer et al.…”

Understanding the population consequences of disturbance

“…The PCoD approach provides a means for investigating the physiological and the behavioral drivers of an individual's response to human disturbance, and therefore a population's viability (Cooke et al, 2014). Linking behavioral and physiological changes to demography also facilitates prediction of the effects of climate change on wildlife populations (e.g., Desprez, Jenouvrier, Barbraud, Delord, & Weimerskirch, 2018;Pagano et al, 2018;Weimerskirch, 2018). More generally, the nonlethal effects of human disturbance and environmental change and their repercussions at a population level can be viewed as examples of the fundamental processes regulating trait-mediated, indirect ecological interactions (Ripple & Beschta, 2012;Werner & Peacor, 2003).…”