For the first time since the 1960s, wild otters are living in every county of England. GILES STROTHER tells the tale of the otter’s return and the part played by the Berks, Bucks and Oxon Wildlife Trust

Otters had virtually disappeared from England by the late 1970s, due mainly to the toxic effects of agricultural chemicals, particularly organo- chlorines.

Used in crop protection and parasite control, these were widely used for two decades and led to huge of losses of wildlife, especially top predators such as peregrine falcons, sparrowhawks and the fish-eating otter. Legislation controlling these persistent poisons has enabled such species to thrive again.

The recolonisation of England by otters is a remarkable story. Aided by enthusiasts who bred otters in captivity and released them into suitable habitats, the numbers have gradually built back up to populate nearly every catchment. Protection from hunting has undoubtedly helped and there are signs that in places otters are becoming less shy as they enjoy an untroubled life in our waterways. The first signs of the return to Oxfordshire came in the late 1990s with clues to the presence of one or two animals on the River Thames at the Gloucestershire border. Since then the signs and occasional sightings have been both upstream and downstream of Oxford and it is clear they are passing through the city.

I have found tracks and droppings (very characteristic and known as ‘spraints’) on the Seacourt Stream, near Botley. Our Water Vole Project has recorded regular sprainting on the Oxford Canal.

The sorry tale of the loss of our otters began just after the Second World War, when the use of DDT and related pesticides such as Dieldrin became widespread. Initially used as sprays to control particular global problems such as malaria-carrying mosquitos, their usage soon extended to crop seed-dressings and sheep dips in the lowlands and uplands of the UK.

A growing concern for human health and wildlife was voiced in 1962 when an American, Rachel Carson, wrote Silent Spring which raised concerns about the long-term effects of pesticides. Ten years later DDT was banned in the USA and several European countries quickly followed suit. It wasn’t until 1984 that Britain banned these chemicals and our wildlife gained some respite. Recovery of affected birds was rapid, but otters took a lot longer.

Meanwhile our rivers, particularly in the lowlands, have been much altered. Channels were deepened and straightened to enable effective drainage of farmland and reduce flooding of property. The gravelly shallows and overhanging willows were ripped out, taking with them the hiding places for otters and their fishy prey. This legacy remains, although efforts are now made to avoid the worst impacts and to restore some of the interesting features to our watercourses.

The Berks, Bucks & Oxon Wildlife Trust, in partnership with the Environment Agency, began work 20 years ago with riverine landowners, advising on wildlife-friendly measures and building holts on the bankside to encourage otters to lie up or even to stay and breed. Breeding happens once a year at most, as the cubs remain dependent on their mother for a whole year. Eventually the young ones disperse and seek new territories and so the otters spread into new waters. Otters use any available habitat along the river including ditches, lakes, ponds and woodland. They eat fish but also will dine on frogs, crayfish, waterfowl and small mammals. You are unlikely to see one in action as they are usually nocturnal in freshwater, but if in the right place at the right time you never know, you might just glimpse a broad muzzle and the V-shaped wake of a wild otter!

Otters are a great example of a ‘landscape-scale’ species. Males can travel along a 40km stretch of river, so conservation measures need to be similarly wide-ranging. The Wildlife Trust’s vision for a Living Landscape, where wildlife corridors and networks are reconnected fits perfectly with the needs of a family of otters.

The habitats we are creating at Chimney Meadows are ideally suited with wet grassland, pools and ditches alongside the river along with dozens of huge old pollard willows offering sanctuary during daylight. Otters may begin to use Iffley Meadows in Oxford, sandwiched as they are between the Weirs Mill Stream and the main River Thames. The Trust would love to hear from riverbank owners along the Thames and tributaries to talk about how you can help wildlife too.

  • If you would like to find out more about your local Wildlife Trust and how you can become a member, visit a reserve or join an autumn event, visit www.bbowt.org.uk or call 01865 775476.