Eurasian Otters (Lutra lutra) suffered significantly in the UK and were virtually extinct in the 1960s. Their population density has increased since then. Despite the increase, there are only an estimated 10-11 thousand individuals in the wild today.
CONSERVATION STATUS
Historically, otters suffered across Europe due to the increasing intensity of farming during the 20th century. To add to this problem, during this period hunters/poachers illegally captured and killed otters in high numbers. Because of this, the otter population rapidly declined in the second half of the 20th century.
The Eurasian Otter is classified as a near-threatened species; by the International Union for the Conservation of Nature. They are categorized as a priority species in the UK Biodiversity Action Plan and are fully protected in the UK under Schedule 5 of the Wildlife and Countryside Act 1981.
Conservation Status
Size & Appearance
Eurasian otters have a dense double-coated fur coat. Their fur is dark brown on top and a lighter brown underbody. Though, they can appear almost black in the water. They are a typical mustelid shape with short legs and a muscular body. Their nose and eyes are either brown or black, and they have small rounded eyes and webbed feet. Another one of their prominent features is their long whiskers. In summary, they are perfectly evolved to live and hunt in their natural habitat.
Their eyesight is acute both below and above the water, making them ideally suited to aquatic hunting. From personal experience, they appear very visually attuned to movement, but either can’t see you or perhaps choose to ignore you if you are very still; even when you are quite close to them.
In terms of size, they are typically 60-90cm (2-3 ft) long, weigh between 5.9-16.8Kg (13-37 lbs), and stand on their 4 legs at about 30cm (12 in). A mature male dog otter is visibly larger and thicker set than the female otter, but the sex of young otters and mature females can be difficult to identify.
Diet
The Eurasian Otter predominantly feeds on small fish and invertebrates. As carnivores, they will also tackle larger prey such as moorhens or ducks. They will even eat mammals such as rabbits if they get the opportunity.
Habitat
The Eurasian Otter lives in rivers, and canals, as well as in large bodies of water such as lochs and ponds. As alluded to above, being opportunistic hunters, they will also venture into urban areas including fisheries or even ponds.
Behavior
A semi-aquatic animal, they can hold their breath for around a minute to hunt. So when you see them in the wild you will regularly spot them surfacing to grab some air. Their metabolism is high, and consequently, they must eat a large portion of their body weight each day (12% per day for male otters during the winter). They are restless and playful animals and mainly hunt nocturnally. For this reason, your best chance to spot them in the wild is in the early morning.
Otters are typically solitary. However, if the resources in an area allow, they are known to live in small family groups. Both male and female otters can be highly aggressive to others of the same or the opposite sex.
Courtship occurs for a week, and the female takes the role of bringing up the cubs, which don’t split from a family group until around 8 to 12 months. In the wild, otters live for around 3 to 5 years. In captivity, though they are known to live up to 17 years.
Natural Predators
Their main natural predator in the UK are Sea Eagles and Golden Eagles, who will in particular target the cubs.
References
- Atlas of the Mammals of Great Britain & Northern Ireland – ISBN: 978-1784272043 – 2020
- Otters: Ecology, behavior, and conservation – ISBN: 978-0198565864 – 2008
- Distribution: JNCC Data
