A few weeks after his first blog on otters was published on this site, ecologist Paul Chanin was delighted to receive an email from a reader. Not only because it proved that he had at least one reader but also because she had just seen otters on a tributary of the Creedy. Since then he has had a couple of other records of otters seen in the catchment this year, something that would have been unheard of when he first came to the area in the 1980s.
In the 1970s I used to go otter watching at night at Slapton Ley and see them occasionally, but it is not easy - looking out for a brown animal against a brown background, after dark! If only they would come out during the day. Once, on the river Culm near Killerton, I was shining my torch down from a bridge so that I could watch bats foraging, when a pair of bright red eyes appeared, swimming upstream towards me. A bit spooky at first but obviously an otter when it got closer clambered onto the bank. Although I have seen a good number of otters in the Scottish Islands, diurnal (daytime) activity on rivers is rare and I have only had one daytime sighting in Devon in more than 45 years.
In Scotland, otters living on the coast are almost entirely diurnal and it is believed that this is because they can catch fish more easily then. Close to the seashore, otters tend to feed mainly on bottom dwelling sea fish such as eelpout, rocklings and butterfish. During the day, these creatures lie on the bottom and keep still to avoid the risk of being eaten by sea birds. Unlike birds, otters hunt by feel rather than sight in this habitat and so they go fishing during the day when their prey is more vulnerable. At night the fish are much more active and harder to catch. Hans Kruuk, an ecologist who studied otters in Shetland, tested this for himself by trying to catch them by hand in an aquarium tank. During the day, he was able to sneak up on the dozing fish and catch them. At night they were whizzing around the tank and it was much harder.
Otter activity patterns are evidently not the same on rivers and we are not sure why. Certainly, the diet is different. Apart from eels, which do tend to stay close to the bottom, otters feed mainly on fish which swim in midwater. Some freshwater fish, including eels, seem to be nocturnal or at least more active at dawn and dusk, others are more lively during the day.
It has been suggested that otters are active at night to avoid disturbance by people. However, this doesn’t seem to bother coastal otters in Scotland. I have seen them ignoring nearby people and their dogs when foraging. Could it be a hangover from the days of otter hunting (which ceased in the 1970s)? Possibly, but although otter hunting occurred throughout most of England and Wales, in Scotland it was largely confined to the south, in Dumfries, Galloway and the Borders. Otters radio-tracked to the north of this area (Rivers Dee, Don and a tributary of the Tay) were either crepuscular (active at dawn and dusk) or nocturnal, so something else is probably at play here.
Whatever the reason, it is certainly a joy to see otters and a lot easier to do so in daylight. A particularly exciting aspect of the reader’s sighting was that there were three otters. She managed to get a photograph (below) and it is pretty clear that this was a family group which shows that otters have bred on the Creedy Catchment this year. Moreover, the same otter family was spotted at about the same time by another local resident near Lords Meadow.
The cubs are fairly well grown and in a few months they will disperse, either downstream and onto the river Exe or they could cross the watershed and move onto the Taw or the Teign catchments. With the Exe rising on Exmoor and the other two on Dartmoor, this means that these two otter cubs starting their lives on the Creedy could end up almost anywhere in Devon.