MEPS 496:249-262 (2014)  -  DOI: https://doi.org/10.3354/meps10618

ABSTRACT: Hormones link environmental stimuli to the behavioural and/or physiological responses of organisms. The release of corticosterone has major effects on both energy mobilization and its allocation among the various requirements of an individual, especially regarding survival and reproduction. We therefore examined the effects of experimentally elevated baseline corticosterone levels on the foraging behaviour of Adélie penguins Pygoscelis adeliae during chick-rearing. We monitored the at-sea behaviour of corticosterone-implanted and control male birds using time-depth recorders, and monitored the effects of corticosterone treatment on their body conditions as well as their chicks’ body masses and survival. Bio-logged data were examined via traditional measures of diving behaviour as well as fractal analysis as an index of behavioural complexity. Corticosterone administration caused a transient decrease in both overall foraging effort (i.e. reductions in the duration of at-sea trips, the time spent diving and the number of dives performed) and foraging complexity. In contrast, per-dive performance indices suggested an increase in both efficiency and prey pursuit rates. Ultimately, however, we observed no short-term effects of treatment on adult body condition and chick body mass and survival. We conclude that under higher corticosterone levels, sequences of behaviour may become more structured and periodic, as observed in treated birds. The increased energy allocation to dive-scale behaviours observed in treated birds might then reflect an adjustment to intrinsic constraints allowing reductions in energy expenditure at the trip-scale. This study highlights the utility of using both traditional and fractal analyses to better understand scale-dependent responses of animals to energetic and various other environmental challenges.

KEY WORDS: Adélie penguins · Allocation of energy · Bio-logging · Fractal analysis · Stress hormone

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Cite this article as: Cottin M, MacIntosh AJJ, Kato A, Takahashi A, Debin M, Raclot T, Ropert-Coudert Y (2014) Corticosterone administration leads to a transient alteration of foraging behaviour and complexity in a diving seabird. Mar Ecol Prog Ser 496:249-262. https://doi.org/10.3354/meps10618 Export citation Share:    Facebook - - linkedIn