TY  - JOUR
AU  - Cottin Manuelle, MacIntosh Andrew J. J.
PY  - 2014//
TI  - Corticosterone administration leads to a transient alteration of foraging behaviour and complexity in a diving seabird
JO  - MARINE ECOLOGY-PROGRESS SERIES
SP  - 249
EP  - 262
VL  - 496
N2  - Hormones are a link between environmental stimuli and the behavioural and/orphysiological responses of organisms. The release of corticosterone (hereafter CORT) hasmajor effects on both energy mobilization and its allocation among the various requirementsof an individual. However, specific effects of CORT on behaviours related to energyacquisition and, consequently, its allocation with regards to survival and reproduction, arecomplex and remain to be deciphered at a fine scale. We examined here the effects of elevatedbaseline CORT levels on this trade-off through a detailed study of foraging behaviour in theAdélie penguin (Pygoscelis adeliae) during the chick-rearing stage. We monitored the at-seabehaviour of CORT-implanted and control male birds using time-depth recorders, andmonitored the effects of CORT treatment on their body conditions, as well as their chicks’body masses and survival. Bio-logged data were examined via both traditional measures ofdiving behaviour and fractal analysis as an index of behavioural complexity. At the level ofthe foraging trip, CORT administration led to a transient decrease in overall foraging effort(i.e. reductions in the duration of at-sea trips, the time spent diving and the number of divesperformed) as well as the complexity with which treated birds foraged. In contrast, per-diveperformance indices suggest an increase in both efficiency and prey pursuit rates. Thesecontrasting results suggest the importance of assessing diving behaviour at scalesencompassing both entire foraging trips, as well as individual dives. Ultimately, however, weobserved no short-term effects of treatment on either adult body condition or on chick bodymass and survival. We conclude that under conditions of energy constraint, as mimicked byour experimental paradigm, sequences of behaviour may become more structured andperiodic as observed in CORT-treated birds. The increased dive-scale effort observed inCORT-birds could then be a strategy allowing a reduction in trip-scale effort. Indeed, theincreased CORT levels may have forced treated penguins to revert to mechanisms preservingtheir survival by engaging in less costly foraging behaviours. This study highlights the utilityof using both traditional and fractal analyses to better understand the responses of free-livinganimals to energetic challenges and various environmental constraints.
SN  - 0171-8630
UR  - http://dx.doi.org/10.3354/meps10618
N1  - exported from refbase (http://publi.ipev.fr/polar_references/show.php?record=4465), last updated on Tue, 09 Jul 2024 01:31:46 +0200
ID  - CottinManuelle2014
ER  -