The influence of thermoregulatory demand on contact crèching behaviour in Adélie Penguin chicks
(1) We tested the hypothesis that contact behaviour in Adélie Penguin (Pygoscelis adeliae) chicks of crèching age is strongly influenced by thermoregulatory demand. (2) Estimated thermoregulatory costs (% minimal metabolic rate) for early crèche stage (1 kg) chicks were much higher (13.4–121.0%) than for late crèche (3 kg) chicks (0–45.1%). The incidence of contact behaviour […]
Absence of daily rhythms of prolactin and corticosterone in Adelie penguins under continuous daylight
Plasma prolactin and corticosterone levels were measured in free-living Ad6lie Penguins (Pygoscelis adeliae) at TorgersenI sland, Antarctica (64?S latitude), at 4-hr intervals throughout the day during early January 1997 and examined for evidence of a 24-hr rhythm. At this season and latitude, natural daylight is continuous. No significant change in the plasma level of either […]
Acoustic systems are adapted to breeding ecologies: individual recognition in nesting penguins
In all species of penguins studied to date, the display call, or parental call, has been demonstrated experimentally to facilitate identification between mates and between chicks and parents. We investigated parent–chick recognition in two nesting species, the Ade´lie penguin, Pygoscelis adeliae, and the gentoo penguin, P. papua. Through playback experiments, we tested the capacity of […]
A Novel Approach to the Treatment of Bumblefoot in Penguins
Bumblefoot in penguins is a serious disease that, if left untreated, can lead to death. Although unproven in penguins, the cause may be analogous to that in raptors where environmental conditions and husbandry practices are central to the cause and prevention of the problem. We developed a treatment protocol for bumblefoot in penguins that involves […]
Elevated corticosterone levels and severe weather conditions decrease parental investment of incubating Adélie penguins
Abstract Corticosterone, the main stress hormone in birds, mediates resource allocation, allowing animals to adjust their physiology and behaviour to changes in the environment. Incubation is a time and energy-consuming phase of the avian reproductive cycle. It may be terminated prematurely, when the parents’ energy stores are depleted or when environmental conditions are severe. In […]
Decreased prolactin levels reduce parental commitment, egg temperatures, and breeding success of incubating male Adélie penguins
Hormones regulate many aspects of an individual’s phenotype, including various physiological and behavioral traits. Two hormones have been described as important players in the regulation of parental investment in birds: the glucocorticoid hormone corticosterone and prolactin, a pituitary hormone, widely involved in mediating parental behavior. In comparison with corticosterone, the role of prolactin on parental […]