Gentoo penguins are four species, not one, scientists say

Gentoo penguins should be categorized into four different species after analyzing genetic and physical differences between populations in the southern hemisphere, say scientists at the Milner Center for Evolution at the University of Bath.

The researchers say counting as four different species will help conserve them because it’s easier to monitor a decrease in numbers.

Gentoo penguins with the Latin name Pygoscelis papua, live in a range of latitudes in the southern hemisphere and are currently divided into two subspecies, P. p. ellsworthi and P. p. Papua.

The researchers propose raising these two subspecies to the species level and creating two new species, which they named P. poncetii after Australian sea bird conservationist Sally Poncet and P. taeniata in recognition of an earlier suggestion for this name dating back to the 1920s.

Their study, published in the journal Ecology and evolution, studied the genomes of populations living in the Falkland Islands and South Georgia in the southern Atlantic, on the South Shetland Islands in Antarctica and on the Kerguelen Islands in the Indian Ocean.

They used genomic data to create an evolution tree to understand the relationship between different populations. When they combined this data with measurements from museum samples from each of the populations, they found significant morphological (physical) and genetic differences between the four populations.

Dr. Jane Younger, Prize Fellow of the Milner Center for Evolution at the University of Bath, led the study. She said: “For the first time we have shown that these penguins are not only genetically different, but also physically.

“Gentoos tend to stay close to their home colonies, and for hundreds of thousands of years they are geographically isolated from one another, to the point where they no longer cross, although they can easily swim the distance separating them .

“The four species that we propose live in very different latitudes – for example P. ellsworthi lives on the Antarctic continent, while P. poncetii, P. taeniata and P. papua live further north where conditions are milder, so it is not surprising that they have evolved to adapt to their different habitats. ”

Ph.D. Student Josh Tyler said, “They look very much like the untrained eye, but when we measured their skeletons we found statistical differences in the length of their bones and the size and shape of their beaks.

“It’s a similar story to that of giraffes, in which four genetically different species were discovered in 2016.”

The scientists say that by viewing the four populations as separate species, conservationists have a better chance of protecting their diversity because if one of them declines, the threat status changes according to the IUCN Red List.

Dr. Younger said, “Right now gentoo penguin numbers are relatively stable. However, there is evidence that northern populations are moving further south as the climate warms. So we have to watch them closely. ”

The proposed changes to the classification of gentoos will be reviewed by an international scientific committee that will evaluate any evidence contained in the scientific literature before accepting the new taxonomy.

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The first genome comparison gives an insight into the origin of the penguins, the evolution

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More information:
Joshua Tyler, Matthew T. Bonfitto, Susma Reddy, Susma Reddy, Jane L. Younger (2020) “Morphometric and Genetic Evidence for Four Species of Gentoo Penguins” are published in Ecology and evolution. DOI: 10.1002 / ece3.6973

Provided by the University of Bath