The recovery of otters but the decline in water voles

The Good – Otters

Following a period of rapid decline in the latter part of the 20th Century, the European Otter (Lutra lutra) is now showing signs of population recovery and re-colonisation of former habitats. The main reasons for the decline has been attributed to loss of habitat, indirect poisoning from the use of now banned agricultural pesticides accumulating in the food chain, and degraded water quality due to pollution.

Otters receive full legal protection under The Wildlife and Countryside Act 1981 (as amended) and The Conservation of Habitats and Species Regulations 2010. It is a criminal offence to deliberately, capture, disturb, injure or kill them or to damage, destroy or obstruct their breeding or resting places.

In the UK, otters have been recorded using almost every type of waterway such as canals, lakes, ponds, reservoirs, rivers and streams. In England and Wales they are found mostly in freshwater systems but can also utilise suitable coastal habitats.

Surveying for the presence of otters is reliant on field signs and therefore should be carried out in dry weather. A fixed distance, both sides of the watercourse will be examined for signs such as above and under-ground resting sites (couches and holts), droppings (spraints), feeding remnants and tracks.

The Bad – Water Voles

The water vole (Arvicola amphibious) is an herbivorous semi-aquatic rodent, the largest of UK’s three species of vole, similar in size to a brown rat.  They can inhabit most wetland habits, such as canals, marshes, ponds, reed-beds, rivers and streams, but favour stable slow flowing or still waters with steep sided bank sides with sufficient vegetation for food and cover. They create an extensive system of burrows in the bank-sides and can also make nests woven out of vegetation at the base of reeds and rushes, or nest in clumps of rushes or grass tussocks in wet fields and meadows.

Water voles have suffered a major population decline due to the loss and fragmentation of their habitat, and more recently this decline has been accelerated due to predation by the American mink introduced. It is estimated that the species has been from approximately 90% of the sites where it occurred in the last century.

From April 2008 the water vole and its breeding and resting places are fully protected under the Wildlife and Countryside Act 1981 (as amended). The water vole is also a UK Biodiversity Action Plan (BAP) priority terrestrial mammal species.

Direct sightings of water voles are rare, therefore most surveys  to find them along watercourses are based on the presence of signs such as burrows, droppings, feeding stations, footprints and latrines.

How does ecological consultancy fit in with all of this?

Ecological consultants offer advice to a variety of organisations and individuals on issues related to wildlife and the species that are protected, such as otters and water voles. This advice is often in response to planning related requests such as those for major developments like road building, housing development, wind farms or for new factories, schools or hospitals.