Otter & Water Vole Surveys
Otter Surveys
Although they are two very different species they are often surveyed for at the same time, as they are both semi-aquatic riparian mammals. The Otter is a far ranging, European Protected Species that has recently returned to all the river catchments in England, according to the 2009/10 National Otter Survey of England, and is near full carrying capacity in Wales. Therefore it must be assumed that any site with rivers, canals or lakes present has the likelihood of supporting otters.
Otters can be surveyed for at any time of year, with winter producing more evidence, but only when rivers have not flooded. The most important aspects for a development is whether it will affect the holt (den) of an Otter, if it will have a detrimental effect on fish populations (their main food), or whether it will prevent/deter them from using a river to travel along safely. Impacts on fish farms and road crossings are often the most significant issues for otters.
Water Vole Surveys
In contrast to Otters, Water Voles are protected by National rather than European legislation and are only just beginning to recover from a population crash that has resulted in their absence from many rivers and streams where they were once present. They travel much smaller distances but can be locally abundant. The main threats are habitat loss, fragmentation and predation by American Mink.
Water Vole surveys consist of detailed searches for field signs along the banks of water courses and the shores of lakes, ponds and reed beds. The field signs consist of piles of feeding remains, droppings, burrows, latrines and actual sightings.
If you have any questions or would like more information on the above, please call Principal Ecologist Mark Satinet on 01993 864 958 or email info@4acreecology.co.uk.
Photo courtesy of David Kjaer