Remarkable video has been captured of more than 200 polar bears eating a dead bowhead whale off the north-eastern coast of Russia during a Kiwi-led expedition.
Rodney Russ, the owner and founder of Heritage Expeditions, told Newshub the expedition had just completed the first-ever double transit of the northern sea route across the top of Russia, when they saw the bears in their natural habitat.
"As we were cruising down the coast, somebody said to me '[there is] a flock of sheep'," Mr Russ said. "I said impossible, impossible - [there are] no sheep on this island.
"We got binoculars out and we realised then it was polar bear."
Mr Russ said the expedition was passing Wrangel Island, in the Chukchi Sea, north of the passage between Russia and Alaska, which he describes as an "amazing nature reserve, known for polar bears and other wildlife".
There, they launched small zodiac boats from the expedition ship - the Akademik Shokalskiy - to get a closer look, and counted 181 polar bears in or around the carcass of a dead bowhead whale.
There were 50 more coming and going from the area.
"It was a phenomenal sight, unbelievable," Mr Russ told Newshub from Vladivostok.
"As far as we know, this has never been recorded before.
"Never before in the history of the arctic and the polar bears has anybody seen more than 200 polar bears feeding on one dead whale."
He said the bears - males, females and their cubs - were crawling over the whale, looking like a giant flock of sheep.
"It was just one of those sights and experiences that you only will only ever have once in a lifetime, or even two lifetimes or three lifetimes," he adds.
"Polar bears are special. They're very special, and with climate change and lack of ice around, they are suffering with early retreat of ice, but just to see so many feeding on one dead whale was incredible."
The sighting and trip was extra special for Mr Russ, who founded Heritage Expeditions in 1985 and now operates out of Christchurch. This was his final trip as owner, before passing it on.
Next March, his son will take over the company that he has run for more than 20 years.