The Hazel Dormouse in Worcestershire - an update
On behalf of the Worcestershire Dormouse Group
There have been several efforts to increase the understanding of the population and distribution of Dormouse Muscardinus avellanarius in Worcestershire over the years. The newly created Worcestershire Biological Records Centre started to collect records for a mammal atlas in the early 1980s and produced maps up to 1984 which eventually appeared to the Worcestershire Mammal Atlas (Green et al 2012)? Bronwen Bruce (1998), Worcestershire Biodiversity Action Plan Officer at the time, called for more Dormouse recording and many appeals for mammal records were made for the Mammals Atlas between 1995 and 2007. There have also been small numbers of active licensed Dormouse workers within the county since the early 1990’s. The Great Nut Hunt, organised by the People’s Trust for Endangered Species (PTES) in 1993, by a good number of volunteers, provided useful records from the traditional woodland habitats both nationally and within Worcestershire. However, early survey efforts were stop-start and not co-ordinated in any way.
Hastings (1834) commented that Dormouse ‘... is abundant in most of our woods...’. However the County’s first proper record of Dormouse was in 1901 from Rous Lench in the east of the county. Further records are scant, with two from the Dowles area in 1911 and 1913, and Pickvance & Fincher (1962) wrote ‘A few recent records have been noted in Randan Wood and Chaddesley Wood, and at Leigh Sinton and Sheriffs Lench. No doubt a thorough search of suitable woods would bring others to light.’ But it was not until 1976 when people started surveying for the species in earnest.
Classed as being of Least Concern by the IUCN, the Dormouse is common and widespread across its range, which extends across Europe into northern Asia Minor. It has a localised population within the UK and is seen as vulnerable to extinction as the diverse, well maintained, understory vegetation structure it requires depends on the active management of woodland, scrub or mature hedgerows, connected to a well-established network of suitable hedgerows throughout the countryside to allow dispersal. When present in healthy numbers Dormice should be seen as a flagship species for well managed woodland and scrub.
The true UK population is unknown, but the records that exist show there has been a long-term decline in both number and range, with the species being lost from seven counties since Rope’s 1885 national survey. For Worcestershire Rope simply quotes Hastings (1834). As with many mammal species, surveying for Dormice is time-intensive and their cryptic, nocturnal and largely arboreal habits make them difficult to detect. Where dormice do exist their population is often very patchy, mostly due to the significant intensification of the management of hedgerows and the inconsistent or absent management in most English woodlands, which renders a dense understory absent.
The current national range extends across Southern England and Wales and along the Welsh borders. Worcestershire is an important County, lying on the western edge of the Welsh border population, so any expansion or contraction here is seen as significant. Map 1 (01) shows historic records up to 1995 (red stars). Map 2 (02) shows records since 1995 (blue stars) and map 3 (03) combines all the records on the Worcestershire Biological Records Centre (WBRC) database. Aside from one record - a nest in a tube - from a site earmarked for development east of the river Severn to the south west of Worcester, the Dormouse is currently only known in Worcestershire west of the river Severn.
Monitoring, although somewhat irregular, has existed on two Worcestershire Wildlife Trust reserves: Monkwood, where a Dormouse was first found under a log pile on a volunteer work party, and the Knapp and Papermill, since 1995.
Worcestershire’s most well known site for Dormice, Ribbesford Wood, has been monitored as part of a Forest Research project since June 1993 after the discovery of a dead Dormouse along one of the main rides after flailing back in the 1980’s first revealed their presence For a full account of this on-going research see Rudlin 2012.
In 2006 the "Dormice on the Malverns" project completed a comprehensive survey for Dormice in the Malvern Hills area, both in Worcestershire and Herefordshire. Using an entirely voluntary workforce, the optimum habitats within 23 1×1km grid squares were surveyed for Dormice using tubes. Seven sites had positive results confirming historic records in some locations and identifying new sites at others. It was hoped to consolidate this survey with more work in the following years. A number of box schemes are now actively monitored on the hills, however without any financial or long term logistical support it has not been possible to sustain the high level of voluntary work seen in the initial project.
In August 2008 the Worcestershire Dormouse Group was established by Liz Appleton (née Nether), with support from Worcestershire County Council, to create a forum for those actively involved in the surveying and monitoring of this species within the county. The conception of this group came from a review of the Biodiversity Action Plan (BAP) for the species and principally the realisation there were still many gaps in our knowledge in Worcestershire, which could only be answered by co-ordinating the efforts of interested parties. A group also provided us with a chance to co-ordinate the continuation of monitoring on known, mostly National Dormouse Monitoring Programme sites, while opening up the chance for other mammalogists to get the necessary experience to gain a licence to handle Dormice in the hope that they will, in time, find their own sites to regularly monitor.
The group achieved its original objective by pulling together the active surveyors within the county and directing their efforts across priority sites to ensure that both known Dormouse sites are monitored and new sites are surveyed for presence and absence.
Since 2008 the group has surveyed 17 sites, eight of which are either new or had not been surveyed for over ten years. Of the eight new sites, sadly only one has returned positive records: Hunthouse Wood, a Worcestershire Wildlife Trust reserve in the Teme Valley. Of the eight new sites six are east of the Severn. This result does seem to suggest that the population in Worcestershire is now confined to west of the Severn. In the long-term the reintroduction of Dormice into woodland sites just over the border in Warwickshire may change this, adding a potential source to colonise either the Redditch woodlands and the Forest of Feckenham.
The Worcestershire Biological Records Centre is maintaining a negative records database for Dormice which, if nothing else, will help us log survey efforts for the species.
Eight Worcestershire sites are in the National Dormouse Monitoring Project (NDMP) each site with a minimum of 50 boxes, checked in line with the People’s Trust for Endangered Species monitoring protocol, totalling 762 boxes. 375 of these boxes are at Ribbesford Wood and are part of the long running research project studying how Dormice respond to differing management techniques (Trout 2006, Rudlin 2012)
Moving forward the plan is to survey further private woodlands and hedgerows through the establishment of an active Worcestershire Nut Hunt Group. Blackhouse Wood, at Suckley, which the Worcestershire Wildlife Trust are in the process of purchasing, is earmarked to become another NDMP site as there are historic positive nut hunt finds for site (Harry Green pers.com. and Bruce 1998). Crew’s Hill woodland, contiguous with Blackhouse, was surveyed with Dormouse tubes in 2011 and 2012 and both nests and adult Dormice were found on site. And, tantalisingly, dormouse signs (opened hazel nuts) were seen along the hedgerow that runs down from Ravenshill wood to Crews Hill way back in 1998 (Harry Green pers.com. and Bruce 1998), but no one has yet been able to follow up this survey with a tube or box survey to see if dormice are regularly resident within the hedge.
Six further sites have been identified by the Group as being of high importance for survey, in addition to maintaining efforts on the existing NDMP sites. Beyond the traditional woodland sites, there is still much to learn about dormice in the wider Worcestershire countryside. Little is known of how much Dormice use hedgerow networks within the county, though it has always been assumed that there is plenty of good habitat. Records like that from the hedge between Crews Hill and Ravenshill and several confirmed reports of dormice of bird feeders from the Malvern (Hodson 2000), Abberley and Alfrick offer incentive to expand our searches beyond woodland.
Our understanding of how well Dormice can survive in hedgerow and scrub habitats has increased greatly over recent years - see Sue Eden’s (2009) book Living with Dormice - but we have never been able to prove this in Worcestershire. A co-ordinated survey effort would no doubt reveal fascinating results but realistically more active trained licence holders are needed if we are to achieve this without letting the current long-term monitoring slip.
Over 25 volunteers, largely from Worcestershire, have been involved with the surveys and at least four new licence holders have been signed up thanks to the training opportunities the group provides. To handle Dormice (04, 05) requires a licence.
It feels as if the momentum is with us so we hope to be able to update you on our findings soon. If anyone has access to private hedgerows that they think would be suitable for surveying, or is interested in carrying out nut hunts from public rights-of-way please contact: James Hitchcock at firstname.lastname@example.org .
Many thanks to the Worcestershire Biological Records Centre (WBRC) for preparing the distribution maps from records held in their database.
Bruce, B. 1998. Dormice in West Worcestershire - but where? Worcestershire Record, 5:18.
Eden, S. 2009. Living with dormice. Papadakis, Winterbourne
Green, G. H., Birks J. D. S., Schenke, J. M. L. & Trevis, G. H. 2012. Worcestershire’s Mammals. Worcestershire Recorders
Hastings, C. 1834. Illustrations of the natural history of Worcestershire. Published in London by Sherwood, Gilbert & Piper, and by Lees in Worcester.
Hodson, J. 2000. Use of Bird Feeder by Dormice. Worcestershire Record, 9:14.
Pickvance, T. J. & Fincher, F. 1962. Midland Mammals Survey II. Mammals of Worcestershire: A revised list. Proceedings of the Birmingham Natural History and Philosophical Society. Volume 20 pages 2-9.
Rope, G. T. 1885. On the range of dormouse in England and Wales. The Zoologist : a monthly journal of natural history. London.1843-1916. Series 3, volume 9, pages 201-213.
Rudlin, P. 2012 Wyre Forest Dormice 1993–2010. In Green et al 2012.
Trout, R. 2006. Dormice in planted ancient woodland sites. The Dormouse Monitor 2006.
01. Dormouse records to 1995 held by WBRC.
02. Dormouse records 1996 to 2014 held by WBRC.
03. Historic and recent Dormouse records held by WBRC.
04. To handle a Dormouse requires a licence. Nick Saunders
05. To handle a Dormouse requires a licence. Nick Saunders