Southern Right Whales Return to NZ

A Southern right whale off Patagonia in Argentina. The species is particularly social and acrobatic, frequently seen tail slapping and breaching almost entirely out of the water. Michael Catanzariti/Wikimedia

Southern right whales are finding their way home from sub-Antarctic islands to ancestral calving grounds off New Zealand, despite being hunted to extinction there more than 100 years ago, according to a study published in Marine Ecology Progress Series.

It is believed that as many as 30,000 of these whales, Eubalaena australis, used to migrate to New Zealand and Australia every winter to give birth until whaling in the 19th and 20th centuries wiped this population out.

Now, a small population of whales that has been studied since 1995 is reestablishing the original migration pattern.

“We used DNA profiling to confirm that seven whales are now migrating between the sub-Antarctic islands and mainland New Zealand,” said Scott Baker, associate director of the Marine Mammal Institute at OSU who initiated the study, in a press release.

“These are probably just the first pioneers,” he added. “The protected bays of New Zealand are excellent breeding grounds, and I suspect that we may soon see a pulse of new whales following the pioneers, to colonize their former habitat.”

The species was targeted by hunters because they could be pursued by boat from the shore and floated when killed due to their large blubber deposits, leading to the name “right” whale, a name they share with two other species that have similar characteristics.

The “maternal fidelity” to calving grounds off New Zealand would have been lost when those mothers were killed or died.

“This maternal fidelity contributed to the vulnerability of these local populations, which were quickly hunted to extinction using only open boats and hand-held harpoons,” said lead author Emma Carroll, at the University of Auckland, in the release.

However, although the species was not seen around mainland New Zealand for decades, a group of whales persisted in the sub-Antarctic near the Auckland and Campbell Islands.

The whales are playful and swim in close to the shore, making them popular with tourists, as in South Africa and Argentina, where their numbers have recovered to some extent.

“The right whale is remarkably graceful, very spectacular to watch,” Baker said. “There used to be thousands of them in New Zealand and they are now re-discovering their ancestral home. It will be interesting to see what develops.”