Abstract: For seabird species, the presence of conspecifics in a crowded breeding colony can obstruct locally available orientation cues. Thus, navigation to specific locations can present a challenging problem. We investigated short-range orientation in King Penguin (Aptenodytes patagonicus) chicks that live in a large and densely populated colony. The two main objectives were to determine whether chicks displaced to a novel location away from the colony (i) can orient towards the colony and return to their crèche and (ii) rely on visual or non-visual cues for orientation. To address these questions, a circular arena was constructed 100m away from the colony. Chicks were released in the arena during the day and at night. After the orientation experiment in the arena, chicks were allowed to return to their home crèche, if they could. Our results showed that, during day trials, chicks preferred the half of the arena closer to the colony, but not at night. However, at night, birds spent more time on ʻthe colony halfʼ of the arena if the wind blew from the colony direction. When animals were allowed to leave the arena, 98% of chicks homed during the day but only 62% of chicks homed at night. Chicks that homed at night also took longer to find their crèche. The experiments suggest that King Penguin chicks can find their crèche from a novel location. Visual cues are important for homing but, when visual cues are not present, animals are able to make use of other information carried by the wind.

Abstract: d'après le mémoire de thèse de doctorat de J.-C. Roy, UPMC 28 septembre 2007, complété et augmenté.

Abstract: A magnetic observatory was opened at the beginning of 2005 in the inland of Antarctica (lat. 75°06'S, long. 123°23'E). Since the opening, the field is recorded almost continuously at a one second and one minute rate. The base lines of the triaxial variometer are controlled by standard absolute measurements made at a regular rate all over the year. Absolute values of the field components are available at any rate lower than or equal to one second.
Recently, in January 2009, a new data acquisition system was installed. This new system (Magnetic Acquisition and Recording Cell 1.0 -- M.A.R.Cell 1.0, developed by EOST) enables to record data, vectorial and of intensity, resulting from the same logger but also a wide set of instrumental parameters such as temperatures, voltages, ... Several technical and scientific improvements are presented such as the quasi-real time repatriation in Europe of the data automated by email (every half-day, limited by the station network itself).
The new magnetic acquisition system allows : (i) to fulfil the 2003 Intermagnet requirements concerning the acquisition of 1Hz data, (ii) to cope with the difficulties arising in the operation of an observatory in such extreme conditions (as for instance an external temperature varying between minus 30°C and minus 70°C and a total darkness lasting two months), and (iii) to prepare the new requirements of synchronized one second ground data acquisition and dissemination in the context of the forth-coming Swarm satellite mission. .
The validity of the results is discussed in the light of the data provided by the nearest observatories (Dumont d'Urville, Scott Base, Mario Zuchelli base) and in comparison with various global or regional models.

Abstract: Recordings of the Earth’s magnetic field variations are continuously performed at the Concordia Geomagnetic Observatory, at Dome C, in the inland Antarctic continent since 2005. The observatory is jointly operated by INGV (Italy) and EOST (France).
The observatory, located above more than 3000 m of layered ice, is unaffected by crustal field contaminations and it lays inside the Southern polar cup, close to the South Geomagnetic pole. It provides an important contribution to the auroral and polar cup ionosphere studies, besides the valuable input to the global internal field models from an area of the planet scarcely covered by observation points.
According to the Intermagnet standard, a triaxial and a scalar magnetometer are in operation for continuous three-component and scalar field strength recordings at 1-second sampled rate. Absolute measurements are carried out regularly along the year even during the dark months and the very harsh ambient conditions. All the fulfilled requirements make Concordia dataset and important reference for the future Swarm satellite mission.
We report some results since the opening of the observatory and we discuss the validity and quality of the entire dataset in comparison of the nearest Antarctic observatories and preliminary results compared to global and regional models.

Abstract: XXth Intern. Congress of Zoology
Paris, 26-29 août 2008