State-dependent decisions in long-term fasting king penguins, Aptenodytes patagonicus, during courtship and incubation

Using an automatic identification and weighing system, we investigated changes in adult body mass in relation to reproductive behaviour during courtship and incubation in free-living king penguins. Despite stressful nutritional conditions and variability of fast length, the majority of pairs incubated successfully by accumulating large body reserves before fasting, which provided flexibility in fasting strategies. […]

Behavioral and Physiological Significance of Minimum Resting Metabolic Rate in King Penguins

Because fasting king penguins (Aptenodytes patagonicus) need to conserve energy, it is possible that they exhibit particularly low metabolic rates during periods of rest. We investigated the behavioral and physiological aspects of periods of minimum metabolic rate in king penguins under different circumstances. Heart rate (f(H)) measurements were recorded to estimate rate of oxygen consumption […]

Finding a parent in a king penguin colony: the acoustic system of individual recognition

To be fed, a king penguin, Aptenodytes patagonicus , chick must identify the call of its parents, in the continuous background noise of the colony. To study this recognition process, we played back to the chicks parental calls with acoustic parameters modified in the temporal and frequency domains. The parental call is composed of syllables […]

Alloparental feeding in the king penguin

We investigated allofeeding (feeding of offspring by adults other than their own parents) in the king penguin, Aptenodytes patagonicus, a long-lived pelagic bird that faces severe food shortages during its reproduction and in which parents leave their fasting chick in dense cre`ches. A 1-year monitoring of 103 breeding pairs and 70 chicks was carried out […]

Experiments on colour ornaments and mate choice in king penguins

Research on animal ornaments used in mate choice has largely focused on males, particularly for bird species with sexually dimorphic coloured patches of feathers and integument. Relatively less information is available for coloured ornaments of sexually monomorphic species and the use of these ornaments during mate choice. The king penguin, Aptenodytes patagonicus, is a monogamous […]

Eye structure and foraging in King Penguins Aptenodytes patagonicus

Anterior eye structure and retinal visual fields were determined in King Penguins Aptenodytes patagonicus using keratometry and an ophthalmoscopic reflex technique. The cornea is relatively flat (radius 32.9 mm) and hence of low refractive power (10.2 dioptres in air) and this may be correlated with the amphibious nature of penguin vision. The large size of […]

Do penguins dare to walk at night? Visual cues influence king penguin colony arrivals and departures

Orientation based on visual cues can be extremely difficult in crowded bird colonies due to the presence of many individuals. We studied king penguins (Aptenodytes patagonicus) that live in dense colonies and are constantly faced with such problems. Our aims were to describe adult penguin homing paths on land and to test whether visual cues […]

Spatial and Temporal Variability in the Foraging Areas of Breeding King Penguins

King Penguins (Aptenodytes patagonicus) from breeding islands in the Indian Ocean (Crozet and Kerguelen Islands) and the Atlantic Ocean (South Georgia and Falkland Islands) were equipped with global location sensors to compare their foraging patterns during different times of the year. In summer, all birds investigated traveled toward the Antarctic Polar Front (APF), irrespective of […]

Individual breeding decisions and long-term reproductive strategy in the King Penguin Aptenodytes patagonicus

Although studied for 35 years, knowledge of the reproductive biology of the King Penguin Aptenodytes patagonicus remains incomplete. The chick requires more than 12 months of care, which extends the breeding cycle, including moult, to more than one year, i.e. the King Penguin is neither annual nor biennial. In an attempt to resolve ambiguities in […]

The king penguin Aptenodytes patagonicus, a non-nesting bird which selects its breeding habitat

Birds are expected to choose their breeding sites according to ‘ideal’ distribution models (Fretwell & Lucas 1970), so that their reproductive output is maximized (Cody 1985). However, studies of breeding habitat selection hitherto conducted on birds have only concerned true nesting species, that is, species that incubate their eggs in a nest or in a […]