Not all otters use tools, but sea otters use them all the time. A raft typically contains 10 to 100 animals, but the largest raft ever seen contained over 2000 sea otters. Though they typically forage alone, sea otters tend to rest together and link arms in single-sex groups called rafts. Currently stable populations exist in parts of the Russian east coast, Alaska, British Columbia, Washington, and California, with reports of recolonisations in Mexico and Japan. Sea otters are native to the coasts of the northern and eastern North Pacific Ocean. It is found most often in areas with protection from the most severe ocean winds, such as rocky coastlines, thick kelp forests, and barrier reefs. Their droppings are known as spraints and can be identified by an odour that is said to range from musky mown hay to jasmine tea to rotting fish.Ī female sea otter holds her pup out of the water in Alaska (USA). They will also use hollows under trees or old rabbit holes. Otters have their cubs in underground dens called holts, which they dig themselves. Populations in Canada and California are now doing well. This was stopped by the establishment of the International Fur Seal Treaty in 1911. North American sea otters are something of a recent success story after they were brought close to extinction in the 19th century, widely hunted for their fur. However, they have since staged a remarkable comeback in the UK, where they’re now once again present in every single county.īut habitat loss and hunting have brought many populations of other otter species crashing down around the world, especially in more tropical locations. Habitat loss and pollution played a major part in the decline. Eurasian otters numbers decreased drastically throughout the UK in the late 1950s and early 1960s. The answer varies by species and location. Southern sea otters float together as a raft in the waters of Moss Landing, California. When on water, these groups are called rafts, and the largest one ever recorded contained up to 2,000 sea otters. While mothers and pups are usually solitary, sea otters can form social groups of up to a few dozen.
The most gregarious by far are sea otters, which are polygynous (males mate with multiple females). Many are mostly solitary apart from the breeding season, whereas others live in groups all year round. It’s not unusual to see a mother otter with her cubs, but families aside, it depends on the species. Sea otters can reach 9kph underwater, North American river otters are faster at 11kph, and the maximum speed of the giant river otter is an impressive 14kph. To swim faster they use their webbed feet for propulsion and undulate their bodies. They spend the majority of their lives on their backs, only flipping over onto their fronts when greater speed is required. More surprisingly, sea otters are quite slow swimmers, although they are extremely agile. With the giant otters of the Amazon growing up to 2m in length, you can imagine that they can swim pretty speedily when they want to! Many species of river-dwelling otter can swim quite quickly – they have to be strong swimmers to catch fish and fight the flow of the river. © Gavin Bickerton-Jones/Getty Gavin Bickerton-Jones/Getty