Media ReleaseFrom: University of Otago
‘Little Ice Age’ linked to wildlife arrivals in New Zealand
A University of Otago-led study has discovered that the “Little Ice Age” is linked to dramatic shifts in Southern Hemisphere wildlife.
The international research team used ancient DNA and carbon dating to assess archaeological remains from New Zealand and sub-Antarctic coastal sites, while also exploring prehistoric climate signatures from across the Southern Hemisphere.
Study leader Professor Jon Waters, of Otago’s Department of Zoology, says researchers found a “very clear pattern”.
“Cold-adapted sub-Antarctic penguins and sea lions suddenly moved north to mainland New Zealand, right at the start of the Little Ice Age, around 1500 AD.
“One distinctive feature of our spectacular wildlife is how many species have arrived here only over recent centuries.
“This new research points to the role of climate change in redistributing species as conditions shift across the planet,” Professor Waters says.
Australian National University researcher Dr Ceridwen Fraser says there was a clear correlation between the downward spike in temperatures 500 years ago and the arrival of sub-Antarctic species.
“Interestingly, the Little Ice Age seems to have hit the Southern Hemisphere some 50 to 100 years later than the Northern Hemisphere.”
The human-driven extinction of mainland wildlife populations, and the subsequent sudden drop in temperature, is also thought to have decreased the human population of southern New Zealand, which in turn made the region more hospitable for new arrivals from the chilly south.
According to ancient DNA researcher Dr Nic Rawlence, of Otago’s Department of Zoology, the colder conditions “released human hunting pressure, creating opportunities for new species to arrive”.
The Marsden-funded research included team members from the University of Otago and the Australian National University.
The team’s findings have been published this week in the international journal Journal of Biogeography.