The newly-described penguin Eudyptula wilsonae – which inhabited Aotearoa’s shores some three million years ago and has just been described in a new study – is closely related to the little blue penguins alive today. Image / Simone Giovanardi
The newly-described penguin Eudyptula wilsonae – which inhabited Aotearoa’s shores some three million years ago and has just been described in a new study – is closely related to the little blue penguins alive today. Image / Simone Giovanardi
There’s a fresh twist in the curious history of the little blue penguin, with new evidence to suggest Australia’s population of the tiny seabirds might ultimately hail back to an Aotearoa ancestor.
Their study, describing a new but long extinct species, is the latest to have widened our understanding of the prehistoric origins of what are the smallest – and possibly the cutest - penguins living today.
Once thought to have been a single species, little penguins have been revealed by DNA analyses to be two genetically distinct populations: New Zealand’s Eudyptula minor, or kororā, and Australia’s Eudyptula novaehollandiae.
To make things more confusing, an Otago population was also found to be Eudyptula novaehollandiae, with research indicating these tiny Aussie immigrants arrived as recently as the past few hundred years.
The latest study, just published in the Journal of Paleontology, takes the story back even further, to the late Pliocene, more than three million years ago, when Aotearoa – part of the vast and now largely sunken continent Te Riu-a-Māui/Zealandia - was an entirely different world.
It was in this period of our country’s geological history – when local sea surface temperatures were up to 3C warmer than today – that we would have found the penguin species Eudyptula wilsonae roaming shorelines.
Thought to have been around the same size as today’s kororā, the species was discovered from fossils found within the rohe of Ngāti Ruanui and Ngāruahine in South Taranaki, as part of a larger project led by Te Papa Tongarewa’s Alan Tennyson and Felix Marx.
The prehistoric penguin species Eudyptula wilsonae has been described in a new study. Image / Simone Giovanardi
Having been collected by Taranaki local Karl Raubenheimer, the fossils were passed to Tennyson, then eventually photographed, 3D-scanned and measured by Massey University’s Dr Daniel Thomas and colleagues.
“By comparing these fossils to bones from living and extinct penguins and other birds we were able to determine that they were a Eudyptula penguin, like kororā,” said Thomas, the lead author of the new paper.
“We recognised that these fossils belonged to a new species, one with a narrower skull than living kororā.”
The discovery revealed that little penguins like kororā had probably been part of the coastal ecosystems of Aotearoa for the entire time since.
“These fossils and the many others from coastal Taranaki are helping us to recognise that Zealandia has been an important area for seabirds for millions of years.”
The fossils happened to be the earliest evidence of little penguins in the fossil record: the only one smaller known to scientists is Eretiscus, which lived around 22 million years ago in Argentina.
“Eretiscus is an extinct lineage of penguins with no living descendants, whereas Eudyptula wilsonae is very closely related to living kororā.”
Did that mean that Aotearoa could ultimately also lay claim to Australia’s little penguins?
Thomas said that, with the current absence of even older Eudyptula fossils from the Australian fossil record, it was indeed possible Australian little penguins were descendants of a species that once lived here.
Yet, many questions remained.
For instance, Eudyptula were closely related – and more than any other living species – to Spheniscus penguins, which today are found in South Africa and South America, including the famous Galápagos Islands.
Once thought to have been a single species, little penguins have been revealed by DNA analyses to be two genetically distinct populations: New Zealand’s Eudyptula minor, or kororā (pictured) and Australia’s Eudyptula novaehollandiae. Photo / Supplied
“Spheniscus is an ancient lineage for South America, and so we hypothesise that an ancestor to Eudyptula dispersed from South America at least three million years ago and arrived into Oceania,” Thomas said.
“But when? And was it a little Eudyptula-sized penguin that dispersed, or a medium, Spheniscus-sized penguin that subsequently became smaller when it arrived into Zealandia?
“When and why was this lineage from South America recruited into the seabird biodiversity hotspot of Zealandia?
“These are open questions that await further discoveries.”
The newly-described penguin, along with the other last warm-world fauna of Zealandia, were also important to help scientists understand how wildlife communities might change over the coming century.
“With millions of years of environmental change now being compressed into just a few human lifetimes, rising temperatures are enabling tropical animals to expand their ranges, leading to potentially irrevocable changes in wildlife communities in Aotearoa and other higher latitude locations,” Thomas said.
