Otter Species

Otter-like animals have inhabited the earth for the last 30 million years and over the years have undergone subtle changes to the carnivore bodies to exploit the rich aquatic environment.

Otters are members of the Mustelid family which includes badgers, polecats, martens, weasels, stoats and mink.

You can find out more about each of the 13 species below and check out their current conservation status in the Red Data List.

You can find out more about each species in “Otters of the World” available at the Ottershop.

Eurasian Otter (Lutra lutra)

Biological/outstanding features

SIZE	1-1.3m
WEIGHT	7-9 kg
DIET	Fish (80%), birds, small mammals, frogs
GESTATION	9 weeks
OFFSPRING	2-3 cubs
HOME RANGE	20-30 km river 3-4 km coast
PHYSICAL FEATURES	Short limbs, webbed feet and claws - Sensitive whiskers around snout to help detect prey - 2 layers of fur: a thick waterproof outer one and a warm inner one with 50,000 hairs/cm2.
SPECIAL ABILITIES	The Eurasian Otter has an acute sense of sight, smell and hearing. The eyes are placed high on the head so that it can see when the rest of the body is below water.
FACT	Although the otter is an exceptionally good swimmer and fish catcher, it cannot hold its breath for long and the average dive is about 30 seconds. FACT: Otters are the only truly semi-aquatic members of the weasel family
DISTRIBUTION:	Throughout Europe and Asia from Ireland in the west as far as eastern Russia and China. They are also found in north Africa (Morocco, Algeria and Tunisia) and the Middle East (Israel, Jordan, Iraq and Iran). However, numbers in Russia and most of Asia are unknown. The otter in Japan was officially declared extinct in 2012 but camera trap photos of an otter on Tsushima island, in the Nagasaki prefecture were obtained in 2017. They became extinct in Belgium, the Netherlands and Switzerland but were re-introduced to the Netherlands. In Belgium otters seem to be returning by crossing the border from The Netherlands or Germany. In Switzerland there were attempts at reintroductions which failed but now they appear to be returning naturally.
HABITAT:	Lakes and rivers or rocky coasts.
CONSERVATION STATUS:	Near Threatened CITES Appendix I
THE THREAT TO THE SPECIES:	There are many factors that contribute to making the otter's life very hazardous. These include habitat destruction, both on land i.e. the building of roads and the loss of previously undisturbed riverbank systems, and in the water (particularly in the sea, as otters may be caught in fishing nets where they can ultimately drown). Traffic injuries also pose considerable problems for otters, as new roads are built through their previously tranquil homesteads. Pollution from pesticides, PCBs, mercury and oil can all be severely damaging to the otter's health. Research by Cardiff University published in 2013 reported that pollutants may now be effecting the reproductive system of males which obviously has serious implications for breeding. In the 1950s-60s the Eurasian otter disappeared from many parts of the UK and Europe largely due to pollution by organochlorine chemicals for agriculture and heavy metals. As they are at the top of the food chain these chemicals became concentrated in predators including otters and peregrine falcons. At this time otters could still be legally hunted in many areas although now they are legally protected. There has been a lot of work to improve water quality and many of the chemicals have now been banned. However they still persist in the environment and there are a lot of new chemicals in use today. Another serious threat is the risk of an oil spill. On the West Coast of Scotland, the waters of The Minch between Skye and the Outer Hebrides is still a major oil tanker route and it is argued by many that a large spillage is just waiting to happen. In 1989 the Exxon Valdez spill killed thousands of sea otters in Alaska and otters were also affected in 1993 by the Braer disaster in Shetland.
COMMUNICATION:	Otters communicate using vocal expression such as whistles, birdlike twittering and spitting. They can also communicate using spraint. Over 100 different scent components of otter dropping have been identified. About 17 of these are thought to contain information on sex, age and even individual recognition, which can be used by other otters.
SOCIAL STRUCTURE:	Otters tend to live alone, except during mating and for a short time after the cubs are born. The young will stay with the mother for approximately 13-15 months.
AUDIO SAMPLE:

©Stewart Dawber - www.skyehighwildlife.com

Life History

Although otter cubs can be born at any time of the year, we find there is a definite preference for spring and again in late autumn. On average 2-3 cubs are born, weighing only 100g, covered in a pale grey fur and with closed eyes. Otter Holts are lined with grass, reeds , twigs and other vegetation. They develop slowly and the eyes will open in five weeks. At seven weeks they will start to run and take solid food. It is at this time that they will venture out of the holt to toilet outside but they will not go much further until they are 10 weeks old and they are fully weaned at 14 weeks.

Strangely enough, young otters are not natural swimmers and the fluffy coat of the young makes it difficult, so they are often dragged into the water by the mother at 16 weeks old. They learn quickly and soon catch their own food. However they are still dependent on Mum and will stay with her for over a year, on many occasions even up to 15 months.

The juvenile cubs will start to disperse at 14 to 15 months and venture into new areas to find their own territories. Survival in the harsh environment on their own is very difficult as they try to find a territory and good feeding grounds.

Mating takes place at anything from 17-20 months and the male picks up the scent of the female in season and goes looking for her. The two otters chase each other along the shore, disappearing into the sea and diving, swimming and rolling together before mating takes place. The male often stays close to the female for.about a week before venturing on to pastures new.

Otter Runs can be found going inland from the coast with sprainted deposits at various points along them.

Otter Tracks, unlike dogs, have a fifth claw part way up the leg, the otter has five toe marks with clear webbing

To survive in the wild, however, is not easy, particularly for a Carnivore and the otter will be lucky to reach the age of 4. However, there have been instances of otters living from 8-12 years, although possibly only one or two in a hundred will survive until this sort of age.

Distribution of the Eurasian Otter (Lutra lutra)

Data based on Otters of the World (IOSF 2017) which is available at the Otter shop.

Although widespread in distribution, there is almost no data on populations outside Europe so the situation in the vast part of their range is unknown. In parts of Asia there have been no records for several decades; for example in Sumatra, Indonesia, a pet otter rescued in 2020 was the first record of this species in 80 years! Similarly records in north Africa are very sparse.

More information on the African Otters Group

African Clawless Otter (Aonyx capensis)
Spotted Necked Otter (Hydrictis maculicollis formerly Lutra maculicollis)
Congo Clawless Otter (Aonyx congicus)