Otter facts
What is a Mull otter’s name?
Eurasian Otter, Lutra lutra: in Gaelic, Dobhran.
Are the otters on Mull Sea Otters?
No. Our otters are the same species as those found throughout the UK. The reason that they are most often seen in the sea here is because most of their prey items are found in there; the sea is more productive than our rivers or lochs. The true Sea Otter is found in California and Alaska.
How big is an otter on Mull?
Length up to 125cm. Male average weight is 7.9kg. Female average is 6kg.
When do they have their young?
Any time of year but here on Mull there is a peak in April / May and September / October.
How many young do they have?
Between 1 and 4. Usually 2 on Mull.
How long do cubs stay with their mum?
On Mull it is 12 to 18 months, more often 18 months.
How long do otters live?
The oldest otter recorded here was a 12 year old female. Nowadays they rarely live longer than 5 to 6 years; 8 years seems to be the maximum at the present time. So a female otter rarely has more than two litters in her life time as she will not breed until at least her second year, more commonly her third.
Why are otters not living so long now?
We’re unsure, but information from the International Otter Survival Fund seems to indicate a possible link to pollution, especially Mercury and Cadmium.
How much does an otter eat?
Around one and a half kilos of food per day.
What do otters eat?
Mull otters eat mainly salt water fish and crustaceans, foraging in the shallower water around our coast. Prey items include Butterfish, Sea Scorpion, Eelpout, Silver Eel, Conger Eel, Dogfish, Wrasse, Crabs, Trout, Salmon, Rockling. But also frogs, birds, small mammals.
When can I see otters?
Our otters can be active at any time of day, at any state of the tide and in any weather. They tend to forage more in the daytime and are often seen at around half tide.
Where can I see otters?
Anywhere on Mull, especially around the coastline from the shoreline to around 6 metres deep or around 40 metres out.
How do I see otters?
Look for a calm area of water. Dull grey weather makes it easier. Look for anything that may be swimming or diving: it may be a seal or bird, but it could be an otter. Use binoculars or a scope to check. Have a look at our web site for pictures of swimming otters to know what to look for and for further help and guidance.
Remember not to get too close, chase or disturb the otter, give them the respect that they deserve. If taking photographs, please remember that the welfare of the otter is worth more than any picture.
Can otters climb trees?
Yes, providing that the tree is not too large in circumferenc
Did you know that otters have two types of hair?
Outer, coarse, guard hairs around 25mm long and fine inner hairs around 10 -15mm long. A dog has around 15,000 hairs per square inch but on a Mull otter it’s around 140,000 hairs per square inch. Unlike most marine mammals, otters don’t have a layer of insulating blubber to keep them warm. Instead, they rely on the two layers of fur. So otters need to keep their coats in excellent condition. They do this by washing in fresh water, squirming on grass or seaweed and grooming.
What about otters’ senses?
Otters are thought to be short sighted but they are very aware of any movement and good at spotting something that is not normally there. Their hearing is excellent; despite having small ears, they can hear a car door shutting hundreds of metres away! Otters also have a very good sense of smell, so can detect the presence of another otter (or human) from a long way off. They use their sense of small to check spraints; they can tell which male or female otter left the dropping. Otters also use their whiskers just as cats and dogs do, to detect movement by vibrations in the air or water. This helps them catch prey.
And how do they get around?
On land, otters can run at a speed of 18 miles per hour; possibly up to 29mph. In the water, they swim at 6 or 7 mph. They have large webbed feet which they use to push themselves through the water, especially the rear feet. Their large, heavy tails can provide propulsion and steering. An otter can dive to depths of 15 metres. Most dives last around 20 to 30 seconds, although some can be considerably longer. Otters can swim up to 400 metres underwater.
So .. the elusive otter; well groomed, alert, only a bicycle short of a triathlon?
Nigel Burch, MOG Scientific Officer
