An uneven future for the southern survivors
- May 15
- 2 min read
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New international studies, believed to be the most comprehensive look at the population genetics, examined three New Zealand crested penguin species, revealing two different futures emerging for these aquatic birds.
They studied Fiordland/tawaki penguins, erect-crested penguins, and Eastern rockhopper penguins. While Fiordland appear to be doing well, their subantarctic cousins, the erect-crested and eastern rockhopper penguins, are facing challenges.
To conduct their analysis scientists used high-resolution DNA sequencing to analyse thousands of genetic markers from colonies across the South Island, the Antipodes Islands, and the Bounty Islands.
The results offer rare, good news. Fiordland’s tawaki form a single, healthy population with high genetic diversity and strong links between colonies. Researchers believe their resilience comes from their ability to forage across a broad range of marine environments, from Fiordland’s fjords to the open ocean off Rakiura/Stewart Island. Some surveys suggest their numbers are stable or slightly increasing.
“These findings bode well for tawaki if we continue to safeguard their marine habitats,” said lead author Dr Jeff White of Cornell University. The work was published in PLOS One and led by the University of Otago’s Tawaki Project.
However, the situation looks far worse further south. Eastern rockhopper penguins on the Antipodes Islands were found to have low genetic diversity, consistent with decades of population decline. Erect-crested penguins are split into two populations with different outlooks. While those on the Bounty Islands are relatively stable, the Antipodes group is showing signs of decline.
“These findings show why New Zealand’s subantarctic penguins should not be managed as a single unit,” said co-author Dr Thomas Mattern. “The Bounty Island population of erect-crested penguins is hanging on, while those on the Antipodes are heading towards collapse.”
Given these findings, the Bounty Islands may become the last refuge for erect-crested penguins. Proposals to relax fisheries protections in the area are raising concern among researchers.
For now, Fiordland remains a stronghold for tawaki, a reminder that with space and protection, some of New Zealand’s seabirds can still thrive.
ThisWildEarth
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