UK Edition
Only known white killer whale sighted by scientists for first time since 2012
An extremely rare white killer whale - the first adult of its kind ever spotted - has been rediscovered by scientists.
The whale, who they have named Iceberg, was seen off the coast of Russia's Kuril Islands.
Iceberg was last spotted in 2012 off the coast of Kamchatka in eastern Russia, and seems to be still enjoying a healthy life in its pod.
The 22-year-old whale is the only adult Orca ever to have been spotted in the wild.
Just one in ten thousand killer whales, also known as Orcas, are completely white.
Young white killer whales are sometimes seen in the wild, but they usually die before they reach adulthood.
The species usually live to around 30, but can survive until 50 or 60. They mature at 15.
The latest spotting of Iceberg was recorded by American researcher Erich Hoyt, 65, of the Far East Russia Orca Project who was also the very first person to see the animal.
He told the BBC at the time: "We've seen another two white orcas in Russia but they've been young, whereas this is the first time we've seen a mature adult.
"Iceberg seems to be fully socialised; we know that these fish-eating orcas stay with their mothers for life, and as far as we can see he's right behind his mother with presumably his brothers next to him."
Scientists do not yet know why the whales are white, but some think their white colouring could be caused by albinism, a congenital disorder marked by the absence of pigment in the skin.
The Russian Orcas group wrote on Facebook: " Today our paper on Iceberg and other white whales is published in Aquatic Mammals. 5 years on, Iceberg is still travelling with his family of fish-eating orcas, but he isn’t the only all white orca: we’ve now recorded at least 5 and maybe up to 8 different white killer whales .
"Russian waters appear to be the world’s number one area for white killer whales who may be leucistic (patchy white pigmentation) or true albinos. It’s a dubious honor. As reported in our paper, albinism probably indicates inbreeding of small populations."