Hybrid puffins may have emerged in the 20th century due to warming

Two distinct subspecies of Atlantic puffins are actually interbreeding in Norway, probably on account of Arctic warming forcing some birds away from their normal habitat.

The island of Spitsbergen in Svalbard, Norway, is inhabited by the most important subspecies of Atlantic puffin, Fratercula arctica naumanni. Puffins on the island of Røst, roughly 1000 kilometres to the south, belong to a smaller subspecies, Fratercula arctica arctica.

In 2021, researchers reported the invention of hybrid puffins – a mixture of these two subspecies – on Bear Island, which is about midway between Spitsbergen and Røst and can be Norwegian. However it was unknown how not too long ago this hybrid colony appeared.

Oliver Kersten on the College of Oslo in Norway and his colleagues have now analysed genetic samples collected from 22 puffins that lived between 1868 and 1910 on Spitsbergen, Røst and Bear Island. In addition they analysed the genomes of 18 trendy puffins that lived on these islands between 2012 and 2018.

The group’s evaluation revealed that each one puffins on Bear Island till 1910 belonged to the subspecies F. a. arctica. Primarily based on evaluation of the fashionable genomes, Kersten and his colleagues assume the 2 subspecies started interbreeding shortly after 1910.

“The looks of this hybrid puffin inhabitants coincides exactly with the anthropogenic warming of the Arctic, which fairly unexpectedly appears to have triggered a southward shift of the naumanni subspecies from the excessive Arctic,” says Kersten.

“Rising temperatures decreased the meals out there round Spitsbergen, in order that compelled the naumanni puffins to seek for meals elsewhere,” he says.

At current, there isn’t any actual draw back to this hybridisation, as a result of the distinct naumanni and arctica subspecies nonetheless exist on Spitsbergen and Røst, says Kersten. “Having the hybrid puffins truly provides genetic range,” he says. “However there could also be conditions sooner or later the place we lose genetic range as a result of whole members of subspecies are compelled to interbreed, so you might be solely left with hybrid people.”

Comparable hybridisation occasions haven’t but been seen amongst puffins within the UK and North America, but when local weather change displaces the birds out of their native habitats, this may increasingly happen, says Kersten.

“The southward motion of a usually Arctic subspecies can problem the overall notion that world warming will merely push species in direction of the poles,” says David Nogués-Bravo on the College of Copenhagen in Denmark. “It additionally underscores the significance of anticipating and planning for diverse ecological responses to climatic shifts,” he says. However a causal hyperlink between local weather change and this hybridisation hasn’t but been confirmed, he provides.