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 different latitudes of 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: P. poncetii after the Australian sea bird conservationist Sally Poncet and P. taeniata in recognition of an earlier suggestion for this name from the 1920s.
South Georgia Gentoo penguins (P. poncetii) live in more northerly habitats, where conditions are milder than their southern Gentoo cousins who live on the ice of Antarctica. Photo by Gemma Clucas
Her study, published in the journal Ecology and Evolution, examined the genomes of populations living in the Falkland Islands and South Georgia in the southern Atlantic, the South Shetland Islands in Antarctica, and 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, recipient of the Milner Center for Evolution at the University of Bath, led the study. She said, “For the first time we showed that these penguins are not only genetically different, but also physically different.
“Gentoos tend to stay close to their home colonies, and for hundreds of thousands of years they have been so geographically isolated from one another that they no longer cross, although they can easily swim the distance that separates 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 the conditions are milder, and that is not so surprising that they evolved to adapt to their different habitats. “
Graduate 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, where four genetically different species were discovered in 2016.”
Scientists say that viewing the four populations as separate species gives conservationists a better chance of protecting their diversity because if either of them declines, the threat status changes according to the IUCN Red List.
Northern Gentoos live on the Faukland Islands in the southern Atlantic. Photo by Gemma Clucas
Dr. Younger said, “Gentoo penguin numbers are relatively stable at the moment. However, there is evidence that the northern populations are moving further south as the climate warms, so we need to monitor 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.
The study was funded by the American Ornithological Society, the Linnean Society, the American Museum of Natural History, and the Evolution Education Trust. The research team was a collaboration between the University of Bath and scientists from Loyola University Chicago, Cornell University, and the University of Minnesota.
Thank you to the University of Bath for providing this news.
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