Linking individual behaviour and life historybioenergetic mechanisms, eco-evolutionary outcomes and management implications

Abstract

Animal behaviour is a state variable of the individual that deserves special attention given its determinant role in eco-evolutionary processes (Wolf et al. 2007). The decomposition of the behavioural variation in between- and within-individual variability has revealed the existence of consistent between-individual differences referred to as personality or behavioural types (Dall et al. 2004). Five axes of personality are usually recognized (exploration, aggressiveness, activity, sociability and boldness), and individual specificities along them tend to be correlated leading to what is known as behavioural syndromes. Recently, these patterns of covariation have been enlarged to accommodate movement behaviour within a personality-dependent spatial ecology theory (Spiegel et al. 2017). Most animals tend to forage, reproduce and develop any activity within specific bounded space, which leads to the formation of home range (HR) areas (i.e., HR behaviour, Börger et al. 2008). The increasing development of animal tracking technology is providing a huge amount of movement data revealing that HR behaviour is widespread among taxa and shows a large consistent variability, both at within- and between-individual level, which allows to define the existence of well-contrasted spatial behavioural types (SBTs). SBTs, as other personality traits, play an important role in selective processes as those impelled by harvesting activities. The Pace-of-Life-Syndrome (POLS) theory (Réale et al. 2010), hypothesises on how personality traits are expected to be correlated with life history (LH) traits along the fast-slow continuum (Stearns 1992) in the broadest sense. Accordingly, patterns of covariation between specific SBTs, physiology-related features and LHs would be expected to exist whenever they maximize the animal performance in a given environment. However, the way in which behavioural variation at the within-species level is translated to the wide range of LH traits remains a fundamental yet unresolved question, mainly due to the lack of a proper theoretical framework (Mathot & Frankenhuis 2018). Thus, unrevealing the mechanisms behind is certainly scientifically very exciting but also socially relevant. In such a context, this PhD thesis aimed to address from conceptual, empirical and theoretical perspectives cornerstone questions in behavioural ecology: what are the feasible mechanisms underpinning the establishment of HR areas and within-species variation, what are their consequences for animal functioning and performance (i.e., in. LH traits) at the individual and eco-evolutionary levels, or what are the implications for the assessment and conservation of wildlife of the existence of SBTs. The PhD thesis focusses in a fish heavily exploited by recreational fishers but it aims to provide general reasoning applicable to a wide range of wild animals. First, the PhD thesis proposes a mechanistic theory of personality-dependent movement behaviour based on dynamic energy budget models (i.e., a behavioural-bioenergetics theoretical model; Campos-Candela et al. 2018). Second, integrated in the field of animal personality (i.e., decomposition of behavioural variability into within- and between-individual’s components), it addresses empirically the study of behavioural variability in the main axis of personality for a marine fish species and looked for evidences of whether personality-mediated differences in energy acquisition may exist. Aiming to support empirically the possible connections between personality traits and space-use behaviour, the thesis provides some insights on the application of a novel-tracking algorithm (Marti-Puig et al. 2018) to analyse the movement of individual fish submitted to different experimental conditions. Third, it provides two examples of how applying HR-related theoretical concepts may improve the management of natural resources: attending the properties of HR may facilitate the assessment of wildlife using fixed monitoring sampling stations (Campos-Candela et al. 2018a), and considering SBTs may influence the assessment of the status of wild fish stocks (Alos et al. 2018). Finally, the adaptive value of the proposed behavioural-bioenergetics theory is explored by means of dynamic optimization (Mangel & Clark 1988) to understand the eco-evolutionary consequences related with HR variability. In summary, this PhD thesis makes an important contribution to behavioural ecology by developing a unifying theory to test the generality and adaptive value of POLS based on dynamic energy budgets. This behavioural-bioenergetics model connects (1) personality traits (2) HR behaviour, (3) physiology and (4) LH traits through an interwoven of mass/energy fluxes, within which they interact and feedback with the ecological context. Overall, from an eco-evolutionary perspective, the proposed framework constitutes a powerful tool for exploring the ecological role of HR behaviour and predicting what combination of behavioural traits would be evolutionally favoured in a given ecological context. Moving forward to including management scenarios, this unifying theory provides scientifically founded knowledge that would promote to improve natural resource management by attending the behavioural component of animal populations. References: Alos, J., Campos-Candela, A. & Arlinghaus, R. (2018). Emergent hyperdepletion of catch rates caused by spatial behavioural types. ICES J. Mar. Sci., submitted, 1–33. Börger, L., Dalziel, B.D. & Fryxell, J.M. (2008). Are there general mechanisms of animal home range behaviour? A review and prospects for future research. Ecol. Lett., 11, 637–650. Campos-Candela, A., Palmer, M., Balle, S. & Alós, J. (2018a). A camera-based method for estimating absolute density in animals displaying home range behaviour. J. Anim. Ecol., 87, 825–837. Campos-Candela, A., Palmer, M., Balle, S., Álvarez, A. & Alos, J. (2018b). A mechanistic theory of personality-dependent movement behaviour based on dynamic energy budgets. Ecol. Lett., submitted, 1–30. Dall, S.R.X., Houston, A.I. & McNamara, J.M. (2004). The behavioural ecology of personality: Consistent individual differences from an adaptive perspective. Ecol. Lett., 7, 734–739. Mangel, M. & Clark, C.W. (1988). Dynamic Modeling in Behavioral Ecology. Princeton, NJ Princet. Univ. Press. Marti-Puig, P., Serra-Serra, M., Campos-Candela, A., Reig-Bolano, R., Manjabacas, A. & Palmer, M. (2018). Quantitatively scoring behavior from video-recorded, long-lasting fish trajectories. Environ. Model. Softw., 106, 68–76. Mathot, K.J. & Frankenhuis, W.E. (2018). Models of pace-of-life syndromes (POLS): a systematic review. Behav. Ecol. Sociobiol., 72, 41. Réale, D., Garant, D., Humphries, M.M., Bergeron, P., Careau, V. & Montiglio, P.O. (2010). Personality and the emergence of the pace-of-life syndrome concept at the population level. Philos. Trans. R. Soc. B Biol. Sci., 365, 4051–4063. Spiegel, O., Leu, S.T., Bull, C.M. & Sih, A. (2017). What’s your move? Movement as a link between personality and spatial dynamics in animal populations. Ecol. Lett., 20, 3–18. Stearns, S. (1992). The evolution of life histories. Oxford Univ. Press. London, 6, 304–306. Wolf, M., van Doorn, G.S., Leimar, O. & Weissing, F.J. (2007). Life-history trade-offs favour the evolution of animal personalities. Nature, 447, 581–584.