Steller’s sea ape (Simnia marina danica) is an unconfirmed marine animal described from a single sighting by explorer Georg Wilhelm Steller on August 10, 1741, in waters off the Shumagin Islands, Alaska. This is the only animal described by Steller that has not been corroborated by physical evidence or other witnesses.
Georg Wilhelm Steller (1709-1746) was a German naturalist known for his work in Russia and Alaska. He described many species of plants and animals, including Steller’s eider, Steller’s jay, Steller’s sea eagle and the extinct Steller’s sea cow.
In his roughly two-hour encounter with the sea ape, Steller wrote that was able to observe the animal from as close as about 16 feet (4 meters). He described the animal as about 5ft (~1.5 m) long with a head similar to that of a dog. It had large eyes, pointed, erect ears, and long whiskers that he likened to a human moustache. Its tail resembled that of a shark in that the upper lobe was larger than the lower, but it had no forefeet or forefins. Its body was covered with thick grayish hair, but its abdomen was reddish-white. Steller recalled that it resembled an animal illustrated by Conrad Gessner which had been called Simia marina, Latin for “sea ape”. Steller wrote that the animal was capable of raising its front end out of the water for several minutes at a time to observe the ship, and engaged in an amusing juggling behavior with a piece of seaweed. Steller attempted to shoot the animal with a gun but missed.
The ship’s log did not note the sea ape encounter, and Steller’s 1742 governmental report made no mention of it. nor did his De Bestiis Marinis (‘The Beasts of the Sea’). However, he did describe the sea ape in his travel diary, published posthumously as Journal of a Voyage with Bering, 1741-1742
Sailor Miles Smeeton records an entry in his book Misty Islands of an encounter with an animal while sailing in the Aleutian Islands in 1969. His description is remarkably similar to Steller’s. It was seen by Smeeton, his daughter and a friend. They had no idea what the animal was at the time, but after reading the description by Steller some time later, they felt it closely matched their own observations.
According to biographer Dean Littlepage, a young Northern fur seal appears to be the most likely explanation for the sighting. Their forelimbs are set far enough behind on their torso so that they could have been obscured below the waterline, and the “shark-like” tail of the creature may have been the animal’s hind flippers. Steller had already been familiar with fur seals, but Littlepage suggests that the poor lighting conditions during the lengthiest encounter of a probable juvenile fur seal could account for the misidentification.
Other possible explanations have been proposed: a stray Hydrurga leptonyx (Leopard seal) or Monachus schauinslandi (Hawaiian monk seal), which generally match Stellar’s description and physical behavior for the sea ape but both have visible ears and their habitat is far from Alaska; or a Enhydra lutris (sea otter), though Stellar was familiar with them and they are much smaller than the reported dimensions of the sea ape.
Another possibility is that the sea ape did not exist and that Simnia marina danica, or Danish sea ape, was simply a vengeful caricature of the Danish captain of the ship, Vitus Bering. Andrew Thaler, an ecologist, argues this explanation is supported by several factors: Steller’s contentious relationship with Bering; Bering being the only Dane on the ship; the sea ape’s reported long whisker’s (similar to Bering’s facial hair); and the creature’s omission from Steller’s official reports.