Search

 

PressCNRS international magazine

Table of contents

Environmental Biology

Testing Times for King Penguins


penguins

© N. Chatelain/IPHC

A colony of King penguins on Possession Island.



King penguins could in time become extinct as a result of global warming. Such is the alarming conclusion of a recent study by the team led by Yvon Le Maho, research director at the IPHC 1 in Strasbourg. They show that climate change has an impact on both the breeding success and adult survival rate of King penguins, constituting a major threat for the species’ long-term future. For this study 2 Le Maho and his team worked with top specialists in the fields of biomathematics and oceanography.
For over nine years, they monitored a group of 450 penguins breeding in the Crozet Archipelago in the Southern Indian Ocean. It is the first study on penguins and climate change that avoids the bias of flipper bands traditionally used to track seabirds. Instead, the team used subcutaneous electronic tags and placed underground antennas on access routes to the colony. “We were the first team to track penguins electronically,” Le Maho explains. “We had realized that flipper bands had a detrimental effect on animals. The return rate for chicks, which was 40% with bands, grew to over 80% for those with electronic tags.”
The study shows a correlation between increased water temperature where the animals forage during the summer, and lower breeding success. Warmer water has an adverse effect on the entire food chain, from the amount of phytoplankton produced, up to the amount of lanternfish that King penguins feed on and bring back to their newly-hatched chicks.
The team’s other main finding is a decrease in the adult survival rate as a result of higher sea-surface temperature. A 0.26°C increase at the edge of the Antarctic pack-ice zone where adults feed during the winter results in a 9% population decline after two years. This is a particularly gloomy prospect for King penguins, given recent estimates by climatologists of a further warming of 0.4°C over the next 20 years 3. “If these predictions prove to be true, King penguins could be facing extinction,” Le Maho warns.
In light of this serious risk, the question now is whether or not King penguins will be able to adapt to their changing environment. One of the next key objectives for Le Maho’s team will be to determine whether compensating mechanisms, such as a younger breeding age, could appear. “We will continue to capitalize on our database,” Le Maho concludes, “and try to understand, for example, the birds’ capacity to adapt to changes, depending on their age.”

Fabien Buliard

Notes :

1. Institut pluridisciplinaire Hubert Curien (CNRS / Université Strasbourg-I).
2. C. Le Bohec et al., “King penguin population threatened by Southern Ocean warming,” PNAS, 2008. 105: 2493-7.
3. Climate change 2007-Intergovernmental Panel on Climate Change (IPCC).

Contacts :

Yvon Le Maho,
IPHC, Strasbourg.
yvon.lemaho@c-strasbourg.fr


Top

Back to homepageContactcredits