Albatrosses develop attraction to fishing vessels during immaturity but avoid them at old age

Abstract

Animals have to develop novel behaviours to adapt to anthropogenic activities or environmental changes. Fishing vessels constitute a recent feature that attracts albatrosses in large numbers. While they provide a valuable food source through offal and bait, they cause mortalities through bycatch, such that selection on vessel attraction will depend on the cost–benefit balance. We examine whether attraction to fishing and other vessels changes through the lifetime of great albatrosses, and show that attraction differed between age classes, sexes and personality. Juveniles encountered fewer vessels than adults, but also showed a lower attraction to vessels when encountered. Attraction rates, especially for fishing vessels, increased through immaturity to peak during adulthood, decreasing with old age. Shy females had lower attraction to vessels and shy males remained at vessels longer, suggesting that bolder individuals may outcompete shyer ones, with positive consequences for mass gain. These results suggest that attraction to vessels is a learned process, leading to an increase with age, and is not the result of preferential attraction to new objects by juveniles. Overall, our findings have important conservation implications as a result of potential strong differential selection on the risk of bycatch for age classes, personality types, populations and species.

Behavioural plasticity shapes population ageing patterns

“…In such challenging environments, older individuals of long-lived species may play a particularly important role in buffering the effects of poor environmental conditions, as they may act as repositories of ecological knowledge gathered throughout their lives 12,14 . As anthropogenic activities are threatening to change the age structure of populations of endangered species 20,52 , the loss of knowledge and behaviours exhibited by older individuals can hamper the ability of populations adjust to changing environmental conditions [12][13][14]53 .…”

“…Specifically, longitudinal studies that follow long-lived animals throughout most of their lives are rare, mostly due to methodological contraints 15 . This gap hinders the identification of gradual and non-monotonic behavioural changes in the wild or the mechanisms that underlie population-level ageing patterns.Research on behavioural ageing reveals a spectrum of patterns at the population level (Figure 1): some behaviours remain fixed throughout life 16 , while others change, either gradually 2 , or drastically at specific ages (e.g., early 17,18 or late in life 19,20 ; the latter usually associated with senescence and loss of physiological or physical capacities 21,22,3 , Figure 1A). Population-level behavioural changes with age can arise from two, non-mutually exclusive mechanisms.…”

“…Research on behavioural ageing reveals a spectrum of patterns at the population level (Figure 1): some behaviours remain fixed throughout life 16 , while others change, either gradually 2 , or drastically at specific ages (e.g., early 17,18 or late in life 19,20 ; the latter usually associated with senescence and loss of physiological or physical capacities 21,22,3 , Figure 1A). Population-level behavioural changes with age can arise from two, non-mutually exclusive mechanisms.…”

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“…Understanding the at-sea movements of young seabirds aier fledging and un.l they start breeding is necessary to gain a full understanding of a species' use of different sea areas. Such knowledge is essen.al for effec.ve seabird conserva.on, as differences in distribu.on and behaviour between young and adult birds can lead to differen.al exposure to threats (Roman et al 2020;Weimerskirch et al 2023). This is especially important because juvenile and immature individuals can make up a high propor.on of a popula.on and have a large influence on popula.on dynamics (Saether et al 2013), including demographic responses to environmental change (Monaghan 2007;Fay et al 2017).…”

The impact of boldness on demographic rates and life‐history outcomes in the wandering albatross

“…The wandering albatross ( Diomedea exulans ) is a long‐lived seabird species in which personality has been linked to many aspects of its biology. In this species, boldness has been shown to be repeatable and heritable (Patrick et al., 2013), and to correlate with pair‐bond maintenance (Sun, Van de Walle, et al., 2022), parental care behaviours (Mccully et al., 2022), and foraging behaviours (Patrick et al., 2017; Weimerskirch et al., 2023). Foraging behaviours, by reflecting an individual's ability to acquire resources, should have cascading effects on reproduction and survival.…”