Research and monitoring
As much of the Gorge’s wildlife is rare and special, it is vital that wildlife monitoring and research is carried out to guide and inform management work.
The Avon Gorge & Downs Wildlife Project has undertaken rare plant surveys and monitoring work since the project began in 1999.
We have also undertaken surveys for bats, invertebrates and dormice. The national charity Butterfly Conservation and Bristol Zoological Society have carried out annual silky wave moth monitoring since 2000. Bristol Ornithological Club annually records breeding peregrine success. Bristol Naturalists’ Society and Bristol and District Moth Group have also conducted wildlife surveys in the Gorge over the years. Since 2009, members of the Friends of the Downs and Avon Gorge (FOD+AG) have also carried out butterfly monitoring in the Gully and on the Downs, from April to September, as part of the UK Butterfly Monitoring Scheme.
The Universities of Bristol and Oxford, and the Museum of Wales have also carried out research on the rare whitebeam trees. The University of Bristol became a Project partner in 2008 and will help guide future rare plant research and monitoring. Survey and monitoring programmes for the rare plants, insects and other animals including birds and bats should therefore be continued and developed. Research projects with the University of Bristol and others should also be established. This should focus on gaining a greater understanding of the ecology of rare or scarce species and their conservation needs.
Silky wave moth
A nationally rare priority conservation species, the silky wave moth (Idaea dilutaria) can be found in just three areas of the UK. The only area where they occur in England is the Avon Gorge in Bristol.
One of the main reasons for past decline of the silky wave moth has been inappropriate land management for this species and it is vital to obtain more information about the distribution, behaviour and habitat requirements to protect the strongholds of silky wave populations.
Bristol Zoological Society, in partnership with Butterfly Conservation, has been monitoring the silky wave moth for the past 20 years within the Avon Gorge. Since 2011, BZS has carried out regular weekly surveys of six priority and seven satellite sites, on the Bristol and Somerset sides of the Gorge, during the peak flight period of the moth in June and July each year. This provides presence and absence information and gives us a comparison of total numbers of moths during the peak flight period. Habitat assessments are also made, which can help to inform habitat management decisions. Every year this information is compiled into an annual report, which is disseminated to relevant stakeholders and partners.
Each year the Avon Gorge peregrine chicks are ringed at three weeks old. They have a unique metal identification ring fitted on their right leg and a blue plastic colour ring fitted on their left leg. The colour ring has a unique two-letter combination, such as GY. Working closely with the British Mountaineering Council, ringers Ed Drewitt and Hamish Smith have been ringing the chicks under a special schedule 1 licence; peregrines have extra protection that common birds don’t have and require a licence to visit their nests.
The colour rings are spotted by other people when the peregrines fly away from the Avon Gorge and set up home elsewhere. They are often photographed with their rings in flight or when they perch on buildings and cliffs. Occasionally they are found dead and their ring details are submitted to the British Trust for Ornithology. Chicks that have fledged from the Avon Gorge have later been spotted in the Chew Valley, on Tewkesbury Abbey and in east London. Their movements are helping us discover where peregrines travel from the Bristol area and how they are helping to increase their populations in the Midlands and the north-east of England.
Information about butterfly monitoring will be coming soon.
Information about dormice monitoring will be coming soon.
Research and monitoring in Leigh Woods
Photographs: Meadow on the Downs (© Denice Stout), Avon whitebeam (© Libby Houston), Common blue butterfly (© Emma Davis), Common blue butterfly (© Helen Hall), Marbled white and gatekeeper butterflies (© Kelly Thomas – Butterfly Conservation), Small blue butterfly (© Hugh Welford), Silky wave moth (© Mark Parsons – Butterfly Conservation), Peregrine chick ringing (© Denice Stout), Dormouse (© Forestry Commission). All other photos © Avon Gorge & Downs Wildlife Project.