Steller's sea bear

Steller’s sea bear is an unknown species of bear reported by Georg Wilhelm Steller in the early 1740s. The bear was said to live in the temperate forests of the Kuril Islands, a now disputed 10,503 square kilometre archipelago between Japan and the Kamchatka Peninsula in eastern Siberia.

Georg Wilhelm Steller was a German naturalist and explorer, notable for discovering that New Russia (Alaska) was a part of the same landmass as the Americas. He was also notable for zoological discoveries, including various eiders, eagles, sea lions, jays, and three still undescribed species, one of which being the Steller’s sea bear. 

In his 1751 book De Bestiis Marinis (Beasts of the Sea), he claimed that he was given many accounts by locals of a rare animal called the sea bear, which resembled brown bears, but were white, semi-aquatic, and unusually aggressive. One of the accounts described, that in 1736, a sea bear overturned a boat and ripped to pieces two of the men on board. He described its range as living near the Kuril islands and that they were “more numerous towards Japan”. 

The most common theory as to the identity of Steller’s sea bear is vagrant polar bears who got lost and headed southwards, although no polar bears have been reported anywhere this far south. Another theory is that they’re albino Ussuri brown bears, which do inhabit Japan and some of the southern Kuril Islands, but the detail of them being semi-aquatic and more aggressive than ordinary bears suggests otherwise. 

In 2002, Chris Orrick, a scholar of Steller’s work, suggests that reports of polar bears further north; and fur seals, occasionally dubbed “sea bears” were conflated, although some disagree because despite that fur seals were sometimes called sea bears, they did not resemble or behave similarly to ursids at all, making the mix-up unlikely.