Beached whale first of its kind in New Zealand

The True's beaked whale (skeleton seen above) is one of the rarest whale species. Photo / Supplied

A rare species of whale found washed up on a Haast beach is the first recorded in New Zealand.

A Haast resident found the True's beaked whale carcass near the mouth of Waiatoto River in November.

It has only now been confirmed as the first of its kind in the country.

The skeleton, including a foetus, will now go to Te Papa in Wellington, where it will be available to scientists.

Department of Conservation West Coast marine specialist Don Neale spent the weekend extracting the bones after the 5m-long, 1.4 tonne carcass, which had been left to rot on the beach.

Not a lot is known about the species, but it has populations in the southern Indian Ocean and the north Atlantic.

"This one would be an extension of that southern Indian Ocean one. But is it a straggler, or do they quite often come here? We don't know," Mr Neale said.

"It's incredible to think that we have a huge mammal like this in New Zealand that until now we didn't even know lived here."

Mr Neale said it might be the same whale that briefly stranded alive on the beach at nearby Jackson Bay the day before this one was found dead.

It was identified using genetic analysis at Auckland University, and there was no obvious reason why it died.

True's beaked whales mostly feed on squid, but also eat fish, using in-built sonar to find their prey in the dark waters of the deep ocean. Before it died, it was probably feeding in the deep underwater canyons close to the South Westland coast.

The species is named after Frederick True, a curator at the Smithsonian in the United States. One of the rarest whales in the world, no population estimates are available.

Until now, True's beaked whales were known only from about 20 carcasses and a handful of live sightings, in the southern Indian Ocean and the north Atlantic Ocean.