Protected species

Survey work to determine the presence / likely absence of hazel dormouse can be undertaken using a number of survey methods, the scope and extent of which is informed by geographical location, existing records and the quality and distribution of habitat resources available. Our team will carefully design the scope of habitat assessment and presence / absence surveys in line with the current Dormouse Mitigation Handbook (April 2025), and can undertake the full suite of survey options available:

Desk-based Assessment

We will contact local Biological Records Centres / recording groups and well as consulting published online resources for any existing records of dormice with a dispersal distance of an impact site and review aerial imagery to assess connectivity within the landscape. Results are used to determine where further survey may be required to determine the presence / likely absence of dormice.

Habitat Quality Assessments (HQA)

HQAs are undertaken to establish the need / scope of presence / likely absence surveys, and calculate likely population estimates and inform impact assessment. HQAs assess species diversity and structural complexity of habitats to provide an indication of habitat quality, and therefore level of further survey required and likely carrying capacity of that habitat (if dormice are present).

Presence / likely absence surveys

A range of survey techniques are available to determine presence / likely absence of dormice, including:

• Nest tube surveys – scope of survey determined by a combination of habitat size and quality (HQA) and available survey window. Surveys are possible between April and October, with monthly visits over 3-6 months of survey required)
• Footprint tunnel surveys – the need and scope of additional footprint tunnel surveys is dependant on determined by a combination of habitat size, quality, and available survey window. Surveys are possible between April and October, with twice-monthly surveys over 3-5 months required)
• Supplementary survey methods (to be used in combination with the above) – include nut searches, use of cameras traps, hair tubes and eDNA sampling

Please contact your local ecology team for more information.