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La Lettre
© IPEV/IPHC
© Julien Courtecuisse/CNRS-IPHC
A band, or even better an electronic tag, helps
locate the penguins
To identify each individual animal and locate it without disturbing it is not simple. For this to be done, we
have used for a long time, in penguins, a metal band placed on a flipper of each penguin with numbers
that were easy to read from a certain distance with binoculars. But how were we to make sure that the
resulting hydrodynamic hindrance to the movement of the sea animal caused no injury? It took, in the early
1990s, the invention by Texas Instruments of RFID - radiofrequency identification - which uses electronic
tags of less than one gram implanted under the skin, to have real control animals with no hydrodynamic
hindrance. Thanks to the Bettencourt-Schuller Foundation, this technology, even before being marketed,
enabled us to highlight the impact of a flipper band on the king penguin: compared to control individuals,
the reproductive success of banded individuals reduced from 40% in ten years, and their survival from
16%. The chick survival after three years is halved when it has been wearing a band.
This extreme miniaturization of electronic RFID tags is made possible because they operate without any
battery. Power is supplied by an antenna when the "labelled" animal is less than 50 cm from it; in return, the
antenna takes down the number corresponding to the label. It’s been 18 years since, within the framework
of the Paul-Emile Victor Polar Institute, antennas have been buried on three passage points in a large area
of the colony of Possession Island, in the Crozet Archipelago, allowing king penguins to be automatically
identified on entering or leaving. This, however, does not enable us to locate them within the colony. In
theory, it could be possible to identify and locate the individuals wearing electronic tags by roving around
in the colony with a manual RFID reader containing the activation-sensor antenna. However, approaching
each animal this way is out of the question as the resulting disturbance would be phenomenal.
Inspired in this by the exploration of Mars, and with means provided by the Total Foundation, we have had
the idea of using rovers, that is to say remote-controlled vehicles. Incubating king penguins defend their
territory against the rover in the same way as they do against their fellows that commute into the colony. By
equipping king penguins with cardiac monitors of the type that is used for jogging, we do not observe the
significant increase in the heartbeat rate that reflects stress caused by the presence of humans - stress
that would make them leave their location in the colony - thus causing its disruption, with the risk of egg
abandonment. At Kerguelen, we have already launched the operational phase.