National Dormouse Database (NDD)

Quality Control

The presence of dormice was identified in several different ways, which are recorded in the dataset under the RecordType attribute. Accompanying reliability scores of Good, Fair and Poor are also given. All records classified as being Good are from reliable sources such as fully trained and licenced monitors, hazel nut shells that have been received by PTES and verified by Dr Pat Morris or photographs that have been verified by PTES.

Method steps

1. Various methods of data capture are used in this dataset. The record type along with the reliability of the data (good, fair or poor) are detailed in the RecordType and RecordTypeReliability attributes. The majority of data are from either Great Nut Hunts, with all confirmed nuts having been verified by Dr Pat Morris, from the NDMP which is carried out by fully trained and licenced dormouse monitors, or from Natural England class survey licence data. Additional ad-hoc records are collected by PTES via the online recording form at http://surveydata.ptes.org/dormousemonitoring but these are only included in the NDD if they can be verified by a photograph, nut or detailed description by an experienced monitor.

England and Wales. The hazel dormouse does not occur in Scotland or Northern Ireland. The dataset has relied largely on contributed data rather than proactive survey, so it suffers from bias towards places that people could readily access during Great Nut Hunts or where NDMP sites have been set up, with higher concentrations of sites potentially occurring in counties where proactive mammal/dormouse groups exist. Grid references normally refer to the centroid of a wood/woodland parcel where the dormouse was found, rather than the actual location.