Due to global warming, two subspecies of puffins mixed at the beginning of the last century, creating a hybrid species.
These are the conclusions of a study published last week in the journal Science Advances by a team of scientists from the University of Oslo. And the cause of this hybridization is to be found in the premises of global warming.
To arrive at these results, the researchers examined the genome of puffins from Bjørnøya, an island around 225 km south of the Svalbard archipelago. They discovered that the puffins that live there are the result of a hybridization process that began in 1910.
North Atlantic puffins are divided into three subspecies. F. a. naumanni found in the High Arctic, Svalbard, eastern Greenland and the northern Baffin Sea. In the rest of the Arctic, notably in Iceland, on the west coast of Greenland and in the north of the American and European continents, the subspecies F. a. arctica which is present. Finally, F. a. grabae is located in the United Kingdom and northern France. Genetic analysis revealed that these three species began to diverge from each other 40,000 years ago. Each of them then evolved independently on different North Atlantic islands.
Then, at the beginning of the 20th century, the species was present in the High Arctic, F. a. naumanni has moved south: “[…] the hybridization between the High Arctic, large-bodied subspecies F. a. naumanni and the temperate, smaller-sized subspecies F. a. arctica began as recently as six generations ago due to an unexpected southward range expansion of F. a. naumanni.” , reveal the authors.
Scientists believe that global warming is the cause of this southward migration. A warming that pushes flora and fauna towards more favorable environments, increasing the potential for hybridization between species or populations of the same species.
At the start of the 19th century, the West began its industrial revolution and started emitting large quantities of greenhouse gases into the atmosphere. Without knowing it, mankind had just laid the foundations for what would become, two centuries later, the greatest threat to its survival and that of other animal and plant species. For puffins, however, the effects of global warming would have been felt a century after the start of the Industrial Revolution, pushing the northern Arctic colonies further south. However, the researchers do not know whether the reason for this shift is linked to a change in temperature or a disruption in the food chain.
But the authors’ observations don’t stop there. They found that the three subspecies that make up the North Atlantic puffin population have lost their genetic diversity over the last century. This is bad news when you consider that a reduction in diversity has a negative impact on reproduction and resistance to disease and parasites.
Species are also more fragile in the face of climate change. “The Atlantic puffin is currently designated as “vulnerable” to extinction globally and “endangered” in Europe.” Oliver Kersten, a postdoctoral fellow in the Department of Biosciences at the University of Oslo and lead author of the article. “Notably, the once world’s largest colony at Røst (Norway) has lost more than 80% of its breeding pairs during the past 40 years. Similarly, Icelandic and Faroese puffins have experienced low productivity and negative population growth since 2003. These population declines have at least in part been ascribed to changes in prey availability as a result of climate change and overfishing.”
Mirjana Binggeli, PolarJournal
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