What is an Otter?
Otters are mammals of the weasel family. There are two distinct species of otters in BC: river otters (Lontra canadensis
) and sea otters (Enhydra lutris
River otters are sleek, usually weigh no more than 14 kg, and have a tail that is about 2/3 the length of their body. They live in dens in riverbanks or shorelines and forage along the shore and in the water. River otters are commonly seen in Victoria area harbours.
Sea otters are larger, weigh up to 45 kg and measure up to 148 cm including their tail, which is about 1/3 the length of their body. They spend most of their time in the ocean. Sea otters are not found in the harbours of the Capital Region, while river otters are fairly common.
Where do otters live? River otters
historically lived throughout North America, though their populations in many areas of the USA have declined due to habitat loss and hunting. They are found throughout Canada, except in the Arctic, in most of their historic range. River otters inhabit coastal shorelines, estuaries and tidal flats, rivers, streams, wetlands, ponds and lakes. River otters are relatively common around Victoria, for example in the more natural areas of Esquimalt Harbour and Esquimalt Lagoon, as well as along the shorelines between Colwood and Sooke.
Historically, sea otters
were found throughout the north Pacific, from Mexico to Alaska, and along the east coast of Russia, south to Japan. However, they were prized for their luxurious fur and hunted to the brink of extinction. Through relocation and restoration efforts, some populations of sea otters are slowly recovering. In BC today, they are found only on the northwest coast of Vancouver Island, in Queen Charlotte Sound and on the mainland near Bella Bella. Currently, no sea otters are known to live in the Victoria area.
How do otters live and reproduce? River otters
eat fish, shellfish, birds and small mammals. With webbed feet, large lung capacity and the ability to shut off circulation to some parts of their bodies, otters are well adapted for diving, and can remain underwater for up to four minutes. Their sensitive whiskers help to sense prey in low light or murky water. They have very dense fur that they must groom often so that it remains well-oiled and clean. Unlike sea otters, river otters catch their prey with their mouths, not their paws.
Female river otters usually give birth to two to five kits, in dens located in hollow logs, burrows dug by other animals, beaver lodges or dense thickets. Kits are helpless for about three weeks after birth, until their eyes open. The mother teaches the kits how to swim and forage, until they can survive on their own at about six months. River otters reach sexual maturity at about two years, and live about 9-12 years in the wild.
River otters are known for their “playful” behaviour, and have been observed repeatedly sliding on their bellies down snow or mud banks. They communicate with buzzes, twitters, staccato chuckles and chirps.
Despite their playful appearance, it is important to remember that river otters are wild creatures, and care must be taken if you come across them. River otters may attack if they feel threatened, so it is especially important to keep pets and children safely away. Always ensure that you keep your dogs on-leash where required, especially if there is a chance of encounters with wild animals. Sea otters
spend most of their time in the ocean, often floating on their backs in “rafts” of 10 to 100 individuals. Sea otters dive for sea urchins, crabs, clams, abalone, mussels, scallops, octopus and squid. They are one of the few animals other than primates known to use tools – they use rocks to crack open the shells of some of their prey. Female sea otters give birth in the water to a single pup, which they care for and train for six to eight months.
Why are otters important?
As predators near the top of the food chain, both types of otters are important members of the diverse landscapes they inhabit. They help to control the populations of their prey, which could otherwise become too large, and consequently more susceptible to disease and starvation. In terms of direct benefits to people, river otters eat some types of fish that compete with commercially valuable species.
Sea otters are important for helping to control populations of sea urchins, a favorite prey. Sea urchins graze on kelp, which in turn hosts a rich diversity of plants and animals. In areas where sea otters have been hunted to extinction, “urchin barrens” are a common sight, in place of highly productive kelp forests.
How have people used otters?
First Nations on Vancouver Island hunted both sea otters and river otters for their meat and pelts, and later participated in the European fur trade.
River otter fur was highly sought after, though it was not quite as valuable as that of the sea otter. Trapping of river otters for their fur continues today, in areas with stable populations.
Watching a sleek river otter foraging for fish along the shoreline is a treat for both tourists and residents in Victoria. Otters form part of the rich mosaic of wildlife that attracts people to British Columbia.
What threatens otters?
Canadian populations of river otters are generally considered to be in good shape. However, concerns may exist in specific areas.
- Oil spills are a major threat for both types of otter, since oil can penetrate their fur and cause hypothermia.
- Since otters are carnivores, some types of toxins can become biomagnified in their bodies. This means that a chemical becomes concentrated in successively higher amounts as it moves up the food chain.
- Once classified as endangered by the Committee on the Status of Endangered Wildlife in Canada, sea otter populations have recovered to the point that they were reclassified in 2007 as a “species of special concern”. They are still protected from hunting, as populations continue to be vulnerable.
How can I help protect otters?
For information on protecting otters, please visit our How Can I Help?
Additional Links ©Images courtesy of Eric Begin & Sparky Leigh