SUB-ANTARCTIC – King penguin colonies in Crozet, Kerguelen and Marion sub-Antarctic islands – more than 70% of the global king penguin population – may be nothing more than a memory in a matter of decades, as global warming will force the birds to move south, or disappear. This is the conclusion of a study carried out by an international team of researchers and published in the journal Nature Climate Change.
"The main issue is that there is only a handful of islands in the Southern Ocean and not all of them are suitable to sustain large breeding colonies" said Robin Cristofari, lead author of the study, from the Institut Pluridisciplinaire Hubert Curien (IPHC) (a mixed research unit of the CNRS and the University of Strasbourg) and the Centre Scientifique de Monaco (CSM).
King penguins are picky animals – in order to form a colony where they can mate, lay eggs and rear chicks over a year, they need tolerable temperatures all year round, no winter sea ice around the island, and smooth beach of sand or pebbles. But, above all, they need an abundant and reliable food source close by to feed their chicks.
For millennia, this seabird has relied on the Antarctic Polar Front, an upwelling front in the Southern Ocean that concentrates an enormous number of fish in a relatively small area. But climate change is causing this area to drift south, away from the islands where most king penguins currently live. Parents are then forced to swim farther to find food, while their chicks are waiting, fasting longer and longer on the shore. The study predicts that, for most colonies, the length of the parents' trips to get food will soon exceed their chicks' resistance to starvation, leading to massive king penguin population crashes, or, hopefully, the king penguins relocating.
Using information hidden in the penguins' genome, the research team reconstructed the changes in the worldwide king penguin population throughout the last 50,000 years, and discovered that past climatic changes, which caused shifts in marine currents, sea-ice distribution and Antarctic Polar Front location, were always linked to critical episodes for king penguins. But there is hope – king penguins have already survived several such crises (the last time was 20,000 years ago), and they may be particularly good at it.
"Extremely low values in indices of genetic differentiation told us that all colonies are connected by a continuous exchange of individuals," said Emiliano Trucchi, formerly at the University of Vienna and now at the University of Ferrara, one of the coordinators of the study.
"In other words, king penguins seem to be able to move around quite a lot to find the safest breeding locations when things turn grim."
But there is a major difference this time – for the first time in the history of penguins, human activities are leading to rapid and irreversible changes in the Earth's system, and remote areas are no exception. In addition to the strong impact of climate change in polar regions, the Southern Ocean is now subject to industrial fishing, and penguins may soon have a very hard time competing for their food.
"There are still some islands further south where king penguins may retreat," said Céline Le Bohec (IPHC and CSM), leader of programme 137 of the French Polar Institut Paul-Emile Victor, where the study was initiated.
"But the competition for breeding sites and for food will be harsh, especially with the other penguin species like the chinstrap, gentoo or Adélie penguins, even without the fisheries. It is difficult to predict the outcome, but there will surely be losses on the way.
"If we want to save anything, proactive and efficient conservation efforts but, above all, coordinated global action against global warming should start now."
Source
King penguins may be on the move very soon [press release], 26 February 2018, University of Vienna
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| King penguins. Photo (c) Celine LeBohec. |
King penguins are picky animals – in order to form a colony where they can mate, lay eggs and rear chicks over a year, they need tolerable temperatures all year round, no winter sea ice around the island, and smooth beach of sand or pebbles. But, above all, they need an abundant and reliable food source close by to feed their chicks.
For millennia, this seabird has relied on the Antarctic Polar Front, an upwelling front in the Southern Ocean that concentrates an enormous number of fish in a relatively small area. But climate change is causing this area to drift south, away from the islands where most king penguins currently live. Parents are then forced to swim farther to find food, while their chicks are waiting, fasting longer and longer on the shore. The study predicts that, for most colonies, the length of the parents' trips to get food will soon exceed their chicks' resistance to starvation, leading to massive king penguin population crashes, or, hopefully, the king penguins relocating.
Using information hidden in the penguins' genome, the research team reconstructed the changes in the worldwide king penguin population throughout the last 50,000 years, and discovered that past climatic changes, which caused shifts in marine currents, sea-ice distribution and Antarctic Polar Front location, were always linked to critical episodes for king penguins. But there is hope – king penguins have already survived several such crises (the last time was 20,000 years ago), and they may be particularly good at it.
"Extremely low values in indices of genetic differentiation told us that all colonies are connected by a continuous exchange of individuals," said Emiliano Trucchi, formerly at the University of Vienna and now at the University of Ferrara, one of the coordinators of the study.
"In other words, king penguins seem to be able to move around quite a lot to find the safest breeding locations when things turn grim."
But there is a major difference this time – for the first time in the history of penguins, human activities are leading to rapid and irreversible changes in the Earth's system, and remote areas are no exception. In addition to the strong impact of climate change in polar regions, the Southern Ocean is now subject to industrial fishing, and penguins may soon have a very hard time competing for their food.
"There are still some islands further south where king penguins may retreat," said Céline Le Bohec (IPHC and CSM), leader of programme 137 of the French Polar Institut Paul-Emile Victor, where the study was initiated.
"But the competition for breeding sites and for food will be harsh, especially with the other penguin species like the chinstrap, gentoo or Adélie penguins, even without the fisheries. It is difficult to predict the outcome, but there will surely be losses on the way.
"If we want to save anything, proactive and efficient conservation efforts but, above all, coordinated global action against global warming should start now."
Source
King penguins may be on the move very soon [press release], 26 February 2018, University of Vienna
Journal citation
Cristofari R., Liu X., Bonadonna F., Cherel Y., Pistorius P., Le Maho Y., Raybaud V., Stenseth N.C., Le Bohec C. and Trucchi E. (2018) Climate-driven range shifts of the king penguin in a fragmented ecosystem. Nature Climate Change. DOI: 10.1038/s41558-018-0084-2
Cristofari R., Liu X., Bonadonna F., Cherel Y., Pistorius P., Le Maho Y., Raybaud V., Stenseth N.C., Le Bohec C. and Trucchi E. (2018) Climate-driven range shifts of the king penguin in a fragmented ecosystem. Nature Climate Change. DOI: 10.1038/s41558-018-0084-2
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