National Water Vole Monitoring Programme (NWVMP)

Quality Control

All data were collected using a standardised method. Participants are provided with training and resources to aid identification of the field signs but it is not possible to verify all records from this survey. Volunteers are encouraged to submit photos of field signs so they can be verified and the experience of the monitor is establish during the registration process. It is also recommended that volunteers gain some practical experience of surveying for water voles before taking part. The data do not represent a complete picture of water vole distriution but should be considered as a sample of sites from across England, Scotland and Wales. The dataset has been checked using NBN Record Cleaner.

Method steps

1. One bank of a 500m stretch of waterway is surveyed to record all water vole field signs (latrines, feeding signs, burrows) and direct sightings within each 100m section. Sites are either ones that were surveyed in the previous national water vole surveys carried out by The Vincent Wildlife Trust (VWT) or have been registered with the programme. Most transect are 500m, but some sites have multiple shorter transects (i.e. 100m) surveyed. Normally one survey is carried out during May but some sites are surveyed again later in the summer. All volunteers are asked about their experience of surveying when registering to take part and photos of signs can be submitted to allow verification.

England, Wales and Scotland. Water voles do not occur in Ireland. Sites surveyed during the the previous VWT national surveys were randomly selected to give a good geographical spread across England, Scotland and Wales, as well as to ensure all habitats were surveyed. However, the majority of the sites selected for the NWVMP were intentionally biased towards those sites that had had water voles present in the previous surveys to ensure surveying is targeted towards sites that have the potential to have water voles present. Survey coverage is not complete however and is lower in areas with fewer volunteers or with less accessible terrain such a upland areas. The grid references normally refer to the location of the start of the transect rather than the precise location of the sighting/signs.