Campaign 2008-09 Oiseaux Plongeurs (IPEV 394)

1/ Foraging strategy and variability of oceanographic features

We want to test the hypoythesis that king penguins will exhibit an high foraging site fidelity when prey availability is predictable. We will test this hypothesis at several spatial and temporal scales by investigating whether a brooding king penguin (i.e. potentially very time/distance constraigned because of the need to feed the chick) returns to the same site visited over the last incubation trips. We will instrument king penguins with adequate miniaturized GPS and feeding recorders.

We want to start a study on the individual feeding habits and the role of age/experience in foraging success. The study model will be an inshore, benthic forager, the Kerguelen cormorant. We will start the study by using a cohort of young birds breeding for the first time (3 years old) from studies colonies.

We want to investigate the at-sea distribution of juveniles of several species of penguins over the winter period. It will especially concerns 2 species of sub-antarctic penguins and one of antarctic specie. Very few is known about the distribution at-sea of these species over their first year at sea. In addition the populations of these species in the TAAF and in other localities are decreasing. The study will be performed by using miniaturized geolocators (GLS).

2/ Ecophysiology of diving

The general goal is still the understanding of the apparent discrepancy between the cost of diving measured in captive king penguins and the diving aerobic duration observed in the field. This year will be invested in 2 technical developments, by using new loggers to measure directly the electrocardiogram in free diving birds, and their accurate behaviour (ultra-miniaturized inertial station). We will also continue the study of the proximate factors explaining the variability of body density of the king penguin at surface pressure. This will be performed by measuring in detail in alive birds their body composition and the volume of the different gas compartments. In the pursuit of our long-term study of the diving energetic of the king penguin, we wanted to access to their wintering activities at-sea by using loggers measuring pressure, 2 body temperatures and heart rate frequency implanted for a year.