Otters on the marsh! So what’s next?
19th February 2012: Having established that at least one otter is active along the marsh section of the River Stour, and because of its protected status, it is sensible to minimise disturbance close to the river during marsh workdays. I think, though, we would need to be cutting trees down along the river bank, or at the edge of the wood bordering the corridor to the tenant farmer’s field, or interfering with brash piles in the area of the corridor, before there would be any risk of disturbing otters that “might” be in residence close by.
Otters will set up home in a quiet, secluded place close to water; in a pipe or hole, perhaps; under a brash pile, maybe; or along the banks of rivers and streams, and close to a lake or pond. Often, the holt is screened by tree roots, or something else that will help obscure the entrance. An otter does not always live below ground; it will sometimes rest above ground on a “couch.” A “couch” can be flattened vegetation, or a lie-up under a brash pile or under fallen logs.
75% to 95% of a freshwater otter’s diet is fish – any fish, I don’t think it has a preference. Otters will, if necessary, eat frogs, ground-nesting birds, beetles and ducks, as part of its 1.5 kilo daily food requirement. Small fish are eaten in the water, and large prey is dragged onto dry ground and eaten. Otters are mainly nocturnal animals. In quiet and undisturbed areas, they are active during the day.
The recent otter activity on the marsh could all be down to a transient, or a succession of transients, but it might signify the presence of breeding bitch. It could be that the marsh is a small part of a dog otter’s home range, which might encompass 40 kilometres of waterway, and he could have a number of holts and couches within his territory. Females have smaller home ranges.
Male and female otters usually only come together to mate. One of the signs that mating might be occurring within an area, is the discovery of spraints in prominent places like on rocks, logs and fallen branches, and on grassy mounds. These spraints mark the otter’s territory. Otter spraints are black when fresh and sweet smelling – a little like lavender. Mink spraints smell horrible. I regularly find otter and mink spraints along the large water pipes, and around North Pond.
The male otter plays no part in rearing of cubs and is driven from the holt, by the female, before the young are born.
Otters breed all year round. With a gestation period of 63 days, the bitch will give birth to two or three toothless and blind cubs. These will remain helpless for up to six weeks and will not be allowed in the water before they are three to four months old. They will stay with their mother for up to a year.
So, the possible presence of breeding pair of otters on the marsh is added to my list of things to look out for and to confirm, if possible.