Four species instead of one: groundbreaking research on Gentoo penguins

Four species instead of one

Researchers have determined that gentoo penguins, once thought to be one widely distributed species, are actually divided into four distinct species. The analysis included the full genomes of 64 birds from 10 breeding colonies, almost from the entire range of these animals.

The newly described species was named Pygoscelis kerguelensis. It lives on the Kerguelen Islands, called the Outback Islands in French, located nearly 3.2 thousand km away. kilometers from the nearest permanently inhabited land.

The birds are very similar to other Gentoo penguins - they have a white belly and black back - but they differ genetically, as well as slightly in size and sounds. This is an example of the so-called a cryptic species, i.e. an organism that is almost visually indistinguishable from its close relatives.

The dispute lasted for over a century

The classification of Gentoo penguins has been the subject of scientific controversy for over 100 years. Previously, it was proposed to distinguish up to six subspecies.

There is probably no penguin species whose taxonomy is more debated than that of the gentoo penguin, said Rauri Bowie of the University of California, Berkeley. There has been a dispute for over 100 years about how many species or subspecies there are. This publication tries to answer this question using modern, integrated methods, he added.

In addition to the Kerguelen species, scientists have recognized three populations that were previously classified as subspecies as full species. These are:

Pygoscelis taeniata – found on Crozet, Marion and Macquarie Islands;

Pygoscelis papua – living in the Falkland Islands/Malvinas and Martillo Island in South America;

Pygoscelis ellsworthi – inhabiting the Antarctic Peninsula, the coast of Antarctica and South Georgia.

Isolation favored the emergence of new species

According to the study's authors, the four species diverged in the last 300,000 to 500,000 years. years. The geographical isolation of the islands and the Antarctic Polar Front - a zone of the Southern Ocean where water temperature and salinity change rapidly - played a key role.

Gentoo penguins are less picky about food than some of their relatives. They eat, among others: fish, krill, squid and cuttlefish. Thanks to this, they do not have to go far from the breeding colonies, and they return to the same places over the years. Populations on isolated islands therefore gradually adapted to local conditions.

Climate change a threat to islands

Climate models indicate that by 2050, subantarctic island species could lose suitable habitat in all places where they currently occur. The problem is the lack of nearby areas where the birds could move.

The situation with Pygoscelis ellsworthi, which lives in Antarctica, may be different. As the climate warms, its potential range may move deeper into the continent.

The greatest concerns concern Gentoo penguins in the subantarctic region, emphasized Juliana Vianna from the Andrés Bell National University in Santiago, Chile. She added that nature conservation institutions in the countries involved should take action to protect the three endangered species.

Researchers indicate that in addition to climate change, penguins are also threatened by ocean warming, habitat destruction, rats and dogs, competition with industrial fishing and accidental entanglement in nets.