the GiGLer

The newsletter of Greenspace Information of Greater London CIC

Tales from the riverbank

Alex Draper, London Wildlife Trust

The water vole is a UK priority species for biodiversity conservation. Its presence on a site is a material consideration in planning applications, and under the Wildlife and Countryside Act (1981) it is an offence to damage burrows and nests, or to disturb water voles while they are in their burrows. The water vole is also protected from persecution and unnecessary suffering under the Wild Mammals (Protection) Act (1996). A review is currently underway which will hopefully lead to the water vole being given full protection – making it an offence to take, possess or intentionally kill a water vole.

In 2001 a partnership launched London’s ‘Water Vole Biodiversity Action Plan’. At the same time, the London Water Vole Project was launched to deliver the action plan.The project carries out a programme of distribution surveys and monitoring, in an attempt to answer three questions: Where are London’s water voles? What is their status? And how is this changing? The project’s first task was to collate existing data to set a baseline for future surveying and monitoring. Records were helpfully provided by GGL’s precursor, the Environment Agency and British Waterways, as well by generous local naturalists.This process yielded just 55 water vole records across London, highlighting the urgent need to identify key populations target future work.

The project now has over 600 records which show areas of strategic importance for water vole populations. Although water voles are still widespread in much of the periphery of London, populations are often highly localised and fragmented.

The project has identified important water vole locations within London, including: the key national site of the Inner Thames grazing marshes at Erith, Crayford and Rainham; the Rivers Ingrebourne, Rom and Beam in Havering and in Barking and Dagenham; the River Crane in Hounslow and in Richmond; the River Colne Valley in Hillingdon; and in the area north of Waltham Abbey and at Walthamstow Marsh in the Lee Valley Regional Park. Surveys have also identified where water voles are currently absent but could be considered for reintroduction. The Beverley Brook in Richmond Park and Wimbledon Common, and the River Wandle catchment, have both been identified as possible reintroduction sites.

The water vole project has initiated a programme of survey work of large scale river catchment areas, starting in 2007 with the River Ingrebourne and Roding catchments. These surveys help us to understand local population dynamics and to assess the quality of the river corridor habitat.This information helps to inform further conservation actions. For example, knowing the location of water vole populations and how fragmented they are helps us to aid water vole migration. Water vole colonies can expand or be lost in a relatively short space of time. The water vole project’s ongoing monitoring programme will help to define population trends and give early notice of the need to target conservation action, as well as recording the impact of previous work. Over a hundred 500 metre sections of watercourse are surveyed annually.Water vole surveys involve searching for field signs – primarily burrows, droppings and feeding remains. Where these are found, they are mapped and counted.

Unlike the river catchment surveys, the monitoring survey programme is not designed to survey every water vole colony in one area, but to provide a representative sample across London. Such an extensive investigation of water vole and mink activity requires considerable resources to implement. We are grateful to the dedicated band of volunteers who are central to making a regular monitoring programme sustainable.

If you would like to help with our survey and monitoring work please contact the London water vole project at, or phone 020 7803 4266.

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