Dormouse Surveys

Dormice are a Protected Species and any potential impact to the habitat of dormice will require a survey of the site to ascertain the presence, or absence of dormice on site.

Best practice for a Surveys using dormouse nest tubes.

Surveys should not be limited to habitat perceived as ‘optimal’ but should be undertaken in any areas of affected woody habitat (including adjacent areas if the impact of development is likely to extend beyond the site footprint).

In order to demonstrate a reasonable probability of dormice being absent, a site generally requires at least 50 nest tubes. Obviously, larger sites are likely to require more tubes. These should generally be placed at roughly15m – 20m intervals and these should be left in place (and checked monthly) for the majority of the active season. Each visit to the site which fails to record any evidence of dormice attracts a ‘score’ as per Table 1 below. If a total score of 20 is achieved this can be used as evidence that dormice are probably not present and therefore Natural England European Protected Species Licenses (EPSL) are not required.





















If evidence of dormice presence is recorded, their abundance and location will be recorded and used to help inform any EPSL which might be required. EPSL applications if required, will be subject to further quotations and are not included within this survey quotation. It might also be necessary to provide some form of mitigation within or adjoining site. This can be discussed if the need arises.

It is sometimes possible (with the agreement of the LPA Ecologist) to increase tube density to offset the length of the survey – This option should only be used late in the season as erecting tubes early in the season would not record the dispersal of young and therefore a false negative would be recorded. Consequently, it is sometimes possible to erect 100 tubes (rather than 50) which will ‘double’ the assessment score. Assuming no evidence of dormice is recorded this can be the end of the process. However, if dormice are recorded, it will be necessary to continue the survey until sufficient data for a NE licence application has been collected and this might mean carrying on until the following year.

Please contact us for a site specific quotation –

Please call us on 0800 888 6846 / 07736 458609