Water voles Arvicola amphibius and otters Lutra lutra are key indicators of healthy freshwater ecosystems and are protected under UK and European legislation. Any works affecting rivers, streams, ditches, ponds, or wetlands must consider their potential presence. At Wold Ecology, we provide detailed, compliant surveys that allow developments to progress responsibly while safeguarding these important semi-aquatic mammals.
Our survey methodology follows current CIEEM standards and species-specific best practice, ensuring accurate assessments and legally robust outcomes.
1. Desk Study & Habitat Assessment
We begin by reviewing records, aerial imagery, and local data to understand the ecological history of the site. A habitat walkover then assesses:
Watercourses, banks, and riparian vegetation
Shelter opportunities such as burrows, holts, and resting places
Connectivity to wider wetland networks
This determines the potential for both species to use the area.
2. Water Vole Surveys
During targeted site visits (typically March–October), our ecologists search for characteristic signs, including:
Burrows and lawned entrances
Feeding stations and grazed vegetation
Latrines and territorial markers
Footprints and runways along the bank
We record population presence, distribution, and relative activity across the site.
3. Otter Surveys
Otter surveys require careful, unobtrusive examination of watercourses for:
Spraint (faeces) used to mark territory
Holts, couches, and resting sites
Slides, footprints, and feeding remains
Travel routes and habitat connectivity
These signs help identify how otters move through and use the landscape.
4. Advanced Monitoring (Where Required)
For complex or sensitive sites, we can employ:
Camera traps
These methods provide a fuller understanding of long-term habitat use.
5. Reporting, Licensing & Advice
Our final report outlines all findings and provides clear, proportionate recommendations to ensure full legal compliance. Where necessary, we support Natural England licensing for activities that may affect otters or water voles.
With appropriate mitigation and early planning, infrastructure and freshwater wildlife can coexist successfully. Wold Ecology offers practical, site-specific solutions to help deliver development that respects ecological integrity.
Common mitigation and integration measures include:
Retaining and enhancing riverbanks, ditches, and riparian habitat
Creating new wetland features such as backwaters, ponds, or vegetated margins
Establishing buffer zones to protect burrows, holts, and resting sites
Timing works to avoid sensitive breeding or dispersal periods
Providing culverts or mammal ledges to allow safe passage beneath bridges and roads
Maintaining habitat connectivity along the wider watercourse
Using sensitive construction methods to minimise disturbance
Our aim is to ensure developments meet all legal obligations while contributing positively to freshwater biodiversity.