How we discovered three new penguin species in the Southern Ocean

When you think of scientists discovering new species, you might imagine looking for new types of insects in the Amazon rainforest or deep in the ocean in search of unknown crustaceans. But today most of the new species we discover are hiding in plain sight.

These “hidden” species may appear so similar to their relatives that they are obviously not a different species, but they reveal themselves as such based on the differences in their DNA. These discoveries were made not by traveling the world but in molecular genetics laboratories.

Thanks to a new abundance of genetic data, science is in the midst of a second wave of biodiversity discoveries. Over the past decade, scientists have discovered new species of giraffes, dolphins, birds and orangutans. And now my colleagues and I have identified three new penguin species.

Following the analysis of the DNA and morphology (shape) of the gentoo penguin, we found that it is not one species as previously thought, but rather four independent species. This brings the total number of penguin species to 21, from 18, and with it the potential for further discovery.

In our study of Gentoo penguins, we analyzed the genetic differences between colonies in the Southern Ocean, including the Falkland Islands, South Georgia Island, the Antarctic Peninsula and the Kerguelen Islands. We were surprised to find that the gentoo penguins from these four regions do not cross each other and have become genetically distinct, to the point that the origin of a single penguin can only be identified by its DNA.

We weren’t expecting this because other penguin species, such as the largest king penguin that overlaps in range with gentoo, are known to interbreed between colonies separated by a whopping 7,500km of open ocean. In fact, the degree of genetic divergence between the four colonies of gentoo penguins is so great that we should consider them evolving independently of each other.

The four groups of penguins seem superficially very similar. But when we measured their skulls, bills, fins and legs we found they were significantly different in size, with those living on the Antarctic Peninsula being smaller and those from the larger Falkland Islands.

These physical and genetic differences are large enough that the former gentoo penguin (Pygoscelis papua) is now recognized as four distinct species: P. papua from the Falkland Islands, P. ellsworthi from the Antarctic Peninsula, P. poncetii from South Georgia, and P taeniata from the island Kerguelen.

The four species inhabit distinct environmental conditions over a wide range of latitudes. P. ellsworthi lives on the cold, icy Antarctic Peninsula at a latitude of about 65 south, in stark contrast to the milder conditions experienced by P. taeniata at 49 south. The four species also consume different diets, with the southernmost species eating more krill and less fish.

We now 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.

The division of Gentoo penguins has important conservation implications. Gentoo penguins are listed as “least concern” on the International Union for Conservation of Nature’s Red List of Threatened Species. The total number of gentoo penguins has increased over the past decade and it was thought that gentoo was the penguin species that could benefit most from climate change, also expanding its territory southward.

But this numerical growth is predominantly within the new P. ellsworthi species in the Antarctic Peninsula. Since the 1980s, no population assessments have been carried out for South Georgia or the Kerguelen Islands. Therefore, the conservation status of the new P. poncetii and P. taeniata species is unknown.

Given their location on isolated islands far north of the Antarctic Peninsula, they are almost certainly experiencing different effects of climate change than the thriving P. ellsworthi. The conservation status of all four species needs to be urgently assessed given the ongoing environmental change in the Southern Ocean.

Read more: Emperor penguins could march to extinction if nations fail to stop climate change

Extinctions due to climate change and habitat loss are happening at a truly alarming rate. The discovery of three new species of penguin, arguably one of the most beloved animals on Earth, highlights how little we still know about the extraordinary diversity of life on this planet.

We must continue to search for new species to have the best chance of preserving biodiversity for future generations. Without these efforts, we face the loss of species we didn’t know existed.

Author: Jane Younger – Research Fellow, Department of Biology and Biochemistry, University of Bath