Voluntary recording scheme reveals ongoing decline in the United Kingdom hazel dormouse Muscardinus avellanarius population

Abstract

In order to conserve threatened species, knowledge of the status, trends and trajectories of populations is required. Co‐ordinating collection of these data is challenging, especially for inconspicuous species such as the hazel dormouse Muscardinus avellanarius.

The UK National Dormouse Monitoring Programme (NDMP) is comprised of nest box recording schemes organised by volunteers. The number, size, and coverage of these schemes has varied over time. Such changes risk conflation of genuine population trends with covarying artefacts, including survey effort and expansion into sites of variable quality.

We provide a robust analysis of count data from 400 NDMP sites from 1993 to 2014 and demonstrate that changes in counts are not an artefact of survey characteristics. In relation to the International Union for Conservation of Nature (IUCN) Red List criteria, we conclude that dormouse counts in nest boxes are an index of abundance appropriate to the taxon and allow the inference of population reduction of 72% (95% confidence intervals 62–79%) over the 22 years from 1993 to 2014, equivalent to a mean annual rate of decline of 5.8% (4.5–7.1%). This decline is ongoing.

We highlight difficulties in assigning an IUCN Red List conservation category to a population, given variation in apparent trends over consecutive time‐periods. In eight out of 13 sliding window intervals of 10 years from 1993 to 2014, the 95% confidence intervals overlap a decline of 50%. While...

Source: Mammal Review - April 1, 2017 Category: Zoology Authors: Cecily E. D. Goodwin, David J. Hodgson, Nida Al ‐Fulaij, Sallie Bailey, Steve Langton, Robbie A. Mcdonald Tags: Review Source Type: research