title: Decreasing prolactin levels leads to a lower diving effort but does not affect breeding success in Adélie penguins.
abstract: Current research on seabirds suggests a key role of hormones in the trade-off between self-maintenance and parental investment through their influence on foraging decisions during the breeding period. Although prolactin is known to have major effects on parental care, its role in foraging behavior has rarely been investigated in seabirds to date. The aim of this study was to assess the influence of an experimental decrease in prolactin levels on foraging decisions and its consequences on breeding success in free-living seabirds. To achieve this, we implanted bromocriptine (an inhibitor of prolactin secretion) in male Adélie penguins (Pygoscelis adeliae), monitored their foraging behavior using time-depth recorders over several trips, and recorded their reproductive output. On average 8±0.5days after implantation, we showed that bromocriptine administration led to an efficient decrease in prolactin levels. However, no differences were seen in foraging trip durations between bromocriptine-implanted birds and controls. Moreover, the time spent diving and the number of dives performed per trip were similar in both groups. By contrast, all diving parameters (including diving efficiency) were negatively affected by the treatment during the first at-sea trip following the treatment. Finally, the treatment did not affect adult body condition or chick growth and survival. Our study highlights the short-term negative effect of low prolactin levels on diving effort, but indicates that a short-term and/or low-magnitude decrease in prolactin levels alone is not sufficient to modify consistently the body maintenance or the parental investment of Adélie penguins.
authors: Université de Strasbourg, IPHC, 23 rue Becquerel, 67087 Strasbourg, France; CNRS, UMR7178, 67037 Strasbourg, France. Electronic address: manuelle.cottin@gmail.com.
authors: Manuelle
authors: M
authors: Cottin
authors: Centre d'Etudes Biologiques de Chizé (CEBC), CNRS, F-79360, France.
authors: Olivier
authors: O
authors: Chastel
authors: Université de Strasbourg, IPHC, 23 rue Becquerel, 67087 Strasbourg, France; CNRS, UMR7178, 67037 Strasbourg, France.
authors: Akiko
authors: A
authors: Kato
authors: Université de Strasbourg, IPHC, 23 rue Becquerel, 67087 Strasbourg, France; CNRS, UMR7178, 67037 Strasbourg, France.
authors: Marion
authors: M
authors: Debin
authors: National Institute of Polar Research, 10-3 Midori-cho, Tachikawa, Tokyo 190-8518, Japan.
authors: Akinori
authors: A
authors: Takahashi
authors: Université de Strasbourg, IPHC, 23 rue Becquerel, 67087 Strasbourg, France; CNRS, UMR7178, 67037 Strasbourg, France.
authors: Yan
authors: Y
authors: Ropert-Coudert
authors: Université de Strasbourg, IPHC, 23 rue Becquerel, 67087 Strasbourg, France; CNRS, UMR7178, 67037 Strasbourg, France.
authors: Thierry
authors: T
authors: Raclot
mesh_terms: D000818:Animals; D001070:Appetitive Behavior / Q000187:drug effects / Q000502:physiology*; D001522:Behavior, Animal / Q000502:physiology*; D001971:Bromocriptine / Q000494:pharmacology; D004242:Diving / Q000502:physiology*; D005247:Feeding Behavior / Q000187:drug effects / Q000502:physiology; D006727:Hormone Antagonists / Q000494:pharmacology; D008297:Male; D011388:Prolactin / Q000097:blood*; D012098:Reproduction / Q000187:drug effects / Q000502:physiology*; D046429:Spheniscidae / Q000097:blood / Q000502:physiology*
chemical_list: D006727:Hormone Antagonists; D001971:Bromocriptine; D011388:Prolactin
keywords: Bromocriptine; Foraging; Hormones; Parental effort; Seabirds