Urban Wildlife Series: Eurasian Otter (Lutra lutra)

IUCN Redlist Status: Near Threatened (IUCN 3.1)
National Redlist Status: Vulnerable [B1ab(iii)]
Image taken from the Urban Wildlife Map.

How old were you when you learned that there were Eurasian otters (Lutra lutra) in Sri Lanka, among otter.. I mean other news? I was well into my mid twenties when I found out and I was, to say the least, otterly… ”sigh”, utterly surprised, as I assume you are too. These cuddly critters with majestic whiskers that can give any member of a biker gang, or any 19th century philosopher a run for their money, have called Sri Lanka home for quite a long time. They elude the eye of the public because of their nocturnal or crepuscular (being active during twilight hours) habits. By outward appearance, they sort of look like a mongoose, but unlike mongooses, otters have sleek, smooth fur (making them look as if they have been meticulously combed down by a loved one) and webbed feet with well developed claws. They also have a cute whitish bib that runs down from their chin to chest (they have such good table manners!) which further enables to distinguish the species with ease. In Sinhala, they are known as “diya ballaa / දිය බල්ලා” or “water dog”. I would love to meet the person who named them as such because no self respecting dog that I know would voluntarily take a bath, nor be near a water source unless to drink from it, much to the chagrin of their owners.

They prefer living close to water and their tubby streamlined bodies, equipped with a thick tail, and webbed feet, make them swimmers par excellence. Usually their forelegs are in prayer while they hunt for food and are used to manipulate prey while eating. To further aid them with swimming, their bones are quite dense, thus reducing buoyancy. Their skill in water is matched only by fish, penguin and seals. Sometimes, several otters group together to drive fish to the shallows so that they can catch them with ease. 

The same body structure which makes them Olympic level swimmers, hinders their ability to walk well on land, giving them an adorable prancing gait which will make you stop and go “awww”. They do love a flowing stream but wetlands and tanks will also do, as long as there are dense thickets of vegetation nearby, for them to get their much needed R&R. If you are really lucky, you might see them in the open, near a paddyfield. This is not because they want to pursue a future in agriculture, but because they want to migrate from one stream habitat to the next. Plus the embankments or “niyara / නියර ” as we call them in Sinhala, are teeming with freshwater crabs locally known as “Kakkuttoe / කක්කුට්ටෝ”. Otters help out the local farmers by consuming these crustaceans, as these freshwater crabs make it their life’s work tunneling the living daylights out of these embankments, rendering them useless in the process. 

Otter filmed running into the thickets at the Baddegana Wetland Park. Filmed by Park Manager, Narmada Dangampola.

Their diet which comprises nearly 80% of fish, varies depending on a myriad of local factors such as location, rainfall (more rains mean less visibility in streams making it harder to catch prey like fish), exposure of prey (crabs unlike fish, move slow so it is easy to pick them off), and prey size and availability. If prey is scarce and luck is in their favor, they have the talent to net a sizeable bird like a white-breasted waterhen (Amaurornis phoenicurus) or “korawakkaa / කොරවක්කා” as they are known locally. They do hunt small mammals like rodents but do so very rarely. 

Otters are highly territorial and irrespective of their size, may rule over a large territory (these range from 1 – 40 km in length), if the conditions are right (right amount of prey, suitable water sources, deforestation to a minimum). However, otters go guns blazing only when a member of the same-sex disregards boundaries. But if a female crosses into a male’s territory, he won’t mind her being there. Otters use their droppings or “spraints’ to mark their territory, and you know something is up when the dropping of a certain animal has a specific name (otters are an important part of British culture and folklore). The word spraint comes from the old French word “espraindre” which means “to squeeze out”. If you happen to have violent toothpaste related imagery after this reveal, please accept our apologies.

Natchev et al 2015. Dietary specifications reflect the feeding behaviour of the European otter (Lutra lutra) in “Strandzha” Natural Park (Bulgaria).

They are usually solitary animals and the only groupings you see would be during mating season, when the otter lads go fishing or when an otter mum is with her pups. Otters do not have a fixed breeding season and they breed in the water. Their gestation period (the time taken for an otter pup to develop inside the womb) is roughly about two months, and newborn pups are about 10% the weight of their mother. Like warrens for rabbits, otters have holts (no, not Captain Holt from Brooklyn 99 or halt as in a bus halt) to rear their young. Holts are always burrowed near a good, clean source of water. Pups are born blind and in their early months, they appear to be afraid of water (now the whole Diya Balla shebang makes sense!) until their mothers coax them into it. The young stay with their mother even after nursing ends, until she mates again.

Because they rarely get mentioned or noticed by locals, they enjoy a level of security which is unheard of by many species. But the greatest threat they face is from deforestation and destruction of their aquatic habitats. If the senseless destruction of the wetlands and water pollution continues, they will literally fade into nothingness, leaving those who knew them with memories, and those who never got the chance to know them, with bewilderment.

Urban Wildlife Series: Test your artistic skills

We asked our followers on social media to show us their artistic talents by colouring in the otter this week. Here are the entries we got!

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