Above: ‘We’ve been promoted’: an adult and young P. poncetiion South Georgia. The four gentoo penguin species will receive vernacular (English) names if the research conclusions are confirmed. Photo: Gemma Lucas

 

NUMBERS OF PENGUIN species have just increased from 18 to 21 if a reclassification of Gentoo penguins identified by researchers at the University of Bath is accepted.

The four separate species have been hiding in plain sight, revealed by a study of the genetic make-up of different populations by scientists at the university’s Milner Centre for Evolution. Gentoos (Pygoscelis papua) have traditionally been regarded as a single species with two subspecies, P. p. ellsworthi and P. p. papua.

The study, recently published in Ecology and Evolution, looked at gentoos living in different latitudes of the Southern Hemisphere: the South Shetland Islands in the Antarctic (P. ellsworthi) and, further north, the Falkland Islands (P. papua), and on South Georgia and the Kerguelen Islands, the newly named P. poncetii and P. taeniata respectively.

“Gentoos tend to stick close to their home colonies, and over hundreds of thousands of years have become geographically isolated… to the point where they don’t interbreed, even though they could easily swim the distance that separates them,” says study leader Dr Jane Younger.

Measurements of skulls, bills, flippers and legs showed penguins on the Antarctic Peninsula to be the smallest and those on the Falkland Islands the largest.

“The degree of genetic divergence between the four gentoo penguin populations is so great that we should consider them to be evolving independently of each other,” said Dr Younger.

Researchers believe that counting them as separate species will aid conservation because it will make it easier to monitor declines in numbers.

“Now we need to understand how the four species have adapted to their distinct habitats and how they are likely to respond to environmental changes in the future,” concluded Dr Younger.

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