Hazel Dormice (Muscardinus avellanarius L.) monitoring

We were privleged to be able to support PTES with carrying out the October dormice monitoring at PTES Briddlesford Woods, working to strict COVID-19 guidelines as a group of six, and as households of three groups of two. The weekend being also my only opportunity in 2020 to continue with training towards the goal of holding a dormice licence.

We enjoyed and recorded dormice nests, family groups and individual dormice.

Along with the dormice we also encountered wood mouse (Apodemus sylvaticus) and pygmy shrew (Sorex minutus), in the dormice boxes; as well as the island speciality red squirrel (Sciurus vulgaris) in the woodland canopy above. I also observed a red squirrel careering around the garden of our Air B&B, whilst partaking in my morning coffee.

Hazel Dormice (Muscardinus avellanarius L.) survey with PTES on IOW

An enjoyable and educational weekend undertaking the extensive hazel dormice nest box survey based in woodland on the Isle of Wight, managed by the People's Trust for Endangered Species (PTES).

Along with recording mammal activity. British Trust for Ornithology had requested that data on birds nests also be recorded. All nest box recording activity was undertaken with respect to suitable licences, and supervised by a licence holder for each cohort of surveyors.

Mammal species found by this survey cohort were hazel dormice and wood mouse (Apodemus sylvaticus) - different nest structures were found including woven unstructured, woven structured, brown leaf nest.

Bird's nests were identified as blue tit (Cyanistes caeruleus), great tit (Parus major) - not shown - and wren's (Troglodytes troglodytes). Seperating the first two types of nest was not as easy as the descriptors indicated, as crossover of features was noted when birds were present - as such where birds were not present ID may have been more subjective.

Bee's nests were also found in the nest boxes, the only bees found by this survey cohort was later identifed as belonging to the tree bumblebee (Bombus hypnorum) a recent colonist to the UK - first found in Wiltshire in 2001.







unstructured woven nest
containing single male dormouse

brown leaved nest with single wood mouse



unoccupied blue tit nest (above)
seven recently fledged blue tits in nest (below)

woven structured hazel dormouse nest containing three dormice



wren's nest

Bombus hypnorum (record shot)

Hazel Dormice (Muscardinus avellanarius L.) survey, Noar Hill

The highlight of the morning for our cohort of dormice surveyors, a single torpid female dormice weighing in at 18.5g found in the last nest box checked, sleeping under brown leaves over what may have been an old birds nest.

Earlier a birds nest was found containing 8-10 eggs, although it was unclear whether it remained a viable nest? A quick search of the internet back at home and the origin of the eggs remain uncertain Cf tree-creeper (Certhia familiaris); wren (Troglodytes troglodytes) or blue tit (Cyanistes caeruleus)?

The other cohort of surveyors totalled five dormice on site, including both a breeding and non-breeding pair.

Hazel Dormice (Muscardinus avellanarius L.) nest box survey, Noar Hill

Photos 1-4 processing dormice; Photo 5 white helleborine orchid  (Cephalanthera damasonium)