Eurasian Otter - Madra uisce / Dobhar cú
The Eurasian otter (Madra uisce - Lutra lutra) is found across Asia, Europe, and the North of Africa and inhabits areas near to waterways on the Iveragh peninsula. Having said this, you will certainly need a keen eye (and just an ounce of luck) to catch a glimpse of one. Otters are a solitary and mostly nocturnal species, with most of their activity occurring around dawn and dusk.
A native otter running on land.
The otter belongs to the weasel family ‘Mustelidae’, and is related to Stoats (Easóg), Mink (Minc), and Badgers (Broc). Interestingly, the most common names for otters in Irish translate as water dog: ‘Madra uisce’ (modern Irish) and ‘Dobhar cú’.
Identification
Otters are quite recognizable, especially when on land. Individuals measure from 90 to 130cm from head to tail, and weigh between 7-12 kilograms. This makes them one of the largest mammals you will encounter in Ireland. Their brown fur is darker on top than it is on the underside. They are distinctive for their large size, long whiskers, thick fur, and tapered tail.
Although you might see our native otters in the sea or in brackish waters around estuaries, they are dependent on having access to clean fresh water. They need to clean their fur in fresh water or it will lose its insulation value. Their webbed feet are well adapted to swimming and moving across wet soils.
A native otter walking along the shore.
Lifestyle and diet
Eurasian otters live close to rivers, streams, lakes and coastal lagoons that provide them with access to freshwater and plentiful food sources. However, they also need land where they can hide and rest. Otters build ‘couches’ for resting. These are above ground, often on islands, in reed beds, or river banks with thick vegetation. Below ground, they build ‘holts’, which are their breeding dens where cubs are raised. They are usually well-covered and occur close to, or within, riverbanks in caves, crevices, rock-piles, or amongst the root-systems of bankside trees.
The size of an otter’s territory depends on the availability of food and shelter along their stretch of river or coast. Otters living in areas where food is plentiful can have territories as small as 2km, while those living in areas where food is more limited may have territories of 20km, or more.
Otters are a highly territorial species, and they mark their territories with droppings known as ‘spraints’. These spraints are described as ‘sweet-smelling’, often compared to the scent of mown hay or jasmine tea. Droppings can be found deposited on rocks, on ledges, or at frequently used resting or fishing sites. Keeping an eye out for these spraints is a good way of detecting whether otters are actively using particular stretches of coast or river.
Another hint that otters are in the area is their footprints, which you might find on the beach in the morning as the tide recedes or perhaps along a riverbank. They are a similar size to the footprints of a medium-sized dog. Unlike dogs, otters leave a footprint with five digits (dogs’ have four) and you might also notice the mark left by their ‘heel’.
An otter footprint in the sand - notice the 5 ‘toes’ and the long ‘heel’, which is different to the round paw with four ‘toes’ of a dog’s footprint.
You may notice a stream of bubbles in the surface of water, which can sometimes be a sign that an otter is moving along the bed beneath the water, using their whiskers to sense movement from hidden crabs or fish.
There are many waterways and stretches of coast in Iveragh where you may catch a glimpse of an otter: Valentia Island, Sneem, Waterville and Portmagee to name a few. It is quite a sight to see an otter rolling or diving in an impressive winter wave off Iveragh. You might also notice them in rough seas gripping tightly to a prized crab as they maneuvering towards the shore. Otters that forage along the coasts of Iveragh are a hardy bunch!
The most important food sources for otters are fish [Sticklebacks (Garmachán), Trout (Breac), Salmon (Bradán), Eels (Eascann)], crustaceans and molluscs [Crabs (Portán), Crayfish (Cráifisc), Shellfish (Sliogiasc)]. Amphibians [Common frogs (Frog)] become an important food source for otters in Spring. They occassionally eat birds and small mammals.
An otter swimming and diving off Iveragh’s coastline.
Myths, legends and folklore surrounding the otter
An old Irish tale surrounding the otter describes the ‘dobharchú’ as a creature that is part-dog and part-otter. Although likened to an otter it was said to be far larger and much more vicious. It was described as having entirely white fur, with black tips on its ears and a black cross on its back.
A headstone can be found in Glenade, Co. Leitrim with an image of the dobharchú. It is said that the headstone belongs to that of a woman who was killed by the animal in 1722, while washing clothes at Glenade Lake. When she did not return home that evening, her husband went in search of her only to find the dobharchú asleep on her body.
A note on identification
Our native species should not be confused with the true ‘Sea otter’ (Enhydra lutris), which is an entirely different species found exclusively in the North Pacific Ocean. They are very frequently featured in documentaries, bobbing on their backs above the Kelp forests along the west coast of North America. This species is highly adapted for life in coastal marine habitats and can spend their entire lives in the ocean. The Sea otter is also far larger than Irish otters.
A raft of Sea otters in Morro Bay, California.
Two sets of otter tracks on Derrynane beach
If you are lucky enough to see an otter, sightings can be submitted to the National Biodiversity Data Centre: Recording System :: Mammals (biodiversityireland.ie).
