This is a summary of our Tuesday Talk from 6th March 2018. Thanks Gill!
I saw my first wild otter in a local lake in 2005 and have been hooked ever since. I trained as an otter surveyor with the North Somerset Levels and Moors Project and carried out monthly surveys for them until 2010. I used this experience to help set up the YACWAG (Yatton and Congresbury Wildlife Action Group) Otter Group in 2012. The group monitors and records otter activity in North Somerset, offers advice on all things ottery, and collects otter road casualties for Cardiff University Otter Project, a long running research programme.
Most otters are secretive and active mainly at night, but fortunately they leave their easily recognisable droppings (spraint) on prominent riverside features to mark their territory. This and their distinctive footprints make surveying fairly straightforward.
Our native otter (Lutra lutra) is larger than many people imagine. An adult male can measure 120cm from nose to tail tip. They are solitary and territorial. Beyond mating, males don’t play any part in raising a family. Females are good mothers and care for their cubs for about a year, teaching them the skills they need to survive. Fish make up the bulk of an otter’s diet, but this is supplemented by amphibians, birds and, occasionally, small mammals.
In the mid 1970’s England’s otters hovered on the brink of extinction. This was due to habitat destruction and the widespread use of certain pesticides and industrial chemicals. They were given full protection in 1978 and since then conservation measures, including captive breeding, habitat restoration and the regulation of some harmful chemicals, have been very successful. Otters are now present in every county in England and flourishing in the south west.
This success story hasn’t been without its challenges. Fisheries are honey pots for otters, resulting in loss of revenue and conflict with some anglers. Electric fencing has been shown to be an effective method of exclusion, but this is not always practical and there is a need for further research, and constructive dialogue between all parties concerned.
It is widely thought that the return of otters has resulted in the displacement of American mink, which have been a major cause of water vole decline. Although mink and otters do coexist in some areas, it is likely that otters have some negative effect on mink population, even if it is not as straightforward as originally believed. It is not unknown for otters to prey on water voles, but as they have coexisted for millennia this is unlikely to have a significant effect on any but the smallest populations. On balance the impact of increased otter numbers on the national water vole population is more likely to be positive than negative.
Eight years after my first encounter I still hadn’t seen another otter in the wild, so in late September 2013 I spent a week at Bosherston Lily Ponds in Pembrokeshire, where I was lucky enough to be able to photograph this female with two cubs.