Scottish Dragonfly Conference 2 April 2016
Stephen Corcoran from the BDS Scottish Group chaired the morning session.
David Hill – The Butterfly Conservation Bog Squad and Recording
David gave an introduction about Butterfly Conservation and its aims and noted that 70% of Butterfly species in Britain are in decline. Species in Scotland are doing rather better than the norm, possibly a consequence of climate change, but also possibly through less intense land use than in England. The project he has been running is involved with restoring peatland and particularly lowland raised bogs. Many of these have been damaged by forestry and peat removal. Peat bogs are important as 3in of peat can store as much carbon as a full forest on the same area. Work parties have cleared 28 hectares of scrub and installed over 100 small dams to raise the water level in bogs and prevent them drying out.
Large Heath is a key species for Butterfly Conservation in Scotland. It occurs on only 40 out of 400 lowland bogs and a recent decline has been noted. It has been rather neglected as a species and only 8 sites where it occurs were monitored in 2014 when a minimum of 30 are needed for adequate coverage. The bog squad found two new sites for it, both SSSIs, which would have been expected to have been well recorded. Small Pearl Bordered Fritillary occurs on the edges of peat bogs where there is woodland on dryer land and these sites are becoming the most important habitat for it. Green Hairstreak is declining in Scotland where it feeds on Blaeberry. Over 80 species of macro moth depend on peatlands in addition to the butterflies and David made a plea for all records of butterflies and moths to be reported, especially from peatlands which tend to be under-recorded.
BDS have been involved in Bog Squad work at Logierait Mire SSSI and it was noted that dragonflies could appear and start laying eggs in the pools created behind newly installed dams within days.
David Hepper – iRecord, You Record, and we all Ask NBN
David gave an update on the present position on recording. We have uploaded records up to 2014 to NBN. We have upgraded the website to the latest version of the operating system and it is now stable but there are still issues to be resolved. The distribution maps on the website now only show records which have been verified by BDS and thus most anomalies have been removed. BDS will adopt the CC BY licence so that anyone can use our records in NBN provided they acknowledge the source. He noted that records should be a treasure that is used rather than a hoard that is hidden.
David explained the philosophy behind DragonflyWatch and the 3 levels of recording effort that it includes. He stressed the importance of submitting complete lists of species seen at sites to enable trend data to be generated. A complete list is all adults seen during a visit and might be only a single species. He noted that exuvia are the best proof of breeding that can be obtained. We encourage recorders to us iRecord to log their records. It is a well-managed system, free to use and allows better sharing of records and faster access. Living Records is also recognised as a good system and we will continue to support its use.
David explained how records flow through iRecord, starting with a system validation (which checks that it is compatible with the system requirements), through the record checker (which flags records which are unusual in timing or location) and then verification by the Vice County Recorder. There are a variety of ways that records can be input including use of the Dragonfly Recording App. The aim is to back fill historic dragonfly records in due course. David asked everyone to report any bugs or difficulties with the systems in use so that they can be flagged to the developers.
Pat Batty – Beavers and Dragonflies at Knapdale
Pat talked about her work on surveying the impact of the introduction of Beavers into Knapdale on the dragonfly population there. This work was a small part of the overall monitoring programme that was part of the introduction project. Knapdale is a good area for dragonflies and an area that Pat has previously monitored. 13 species are recorded around the 11 lochs and two of these were likely to be vulnerable to the effects of the Beavers, Hairy Dragonfly and Beautiful Demoiselle.
Three families of Beavers were introduced into the area in 2009 with 2 more subsequently. The Beavers have bred successfully, but at the end of the trial in 2014 there were still only three families. Pat monitored the area in 2009, 2010, 2012 and 2014 using 19 transects, 5 sample points and walking 3 watercourses and recording in 100m segments. There were challenges due to the large area and fairly rugged terrain which became even more difficult after action by the beavers in felling trees and changing water bodies. Weather was also an issue since it affected timing of emergence which occurred over a short period anyway.
The Beavers ate a wide variety of vegetation. They seemed to like water lilies but also ate Saw Sedge (removing 83%) and Club Rush (removing 43%), plants that Hairy Dragonfly seemed to need in their habitat. Numbers of larvae, exuviae and adults reduced in the lochs affected by the Beavers but also seemed to have reduced in lochs that were unaffected. It is difficult to separate out the effects due to variable weather conditions from year to year. It is likely that they had an effect because of the removal of vegetation but it is difficult to tell how much. Pat did note that Four-spotted Chasers occupied areas where vegetation had been removed in place of the Hairy Dragonflies. There was little obvious impact on Beautiful Demoiselles apart from shifting locations where the action of the Beavers changed water flows.
The overall report of the Beaver introduction project, of which Pat’s study forms a part, is with the Scottish Government and their decision on the future is expected this year.
Barbara Mearns – Dumfries and Galloway – not like it used to be!
Wildlife in Dumfries & Galloway is changing. A number of bird species have moved in, including Little Egret, Mediterranean Gull and Nuthatch, as have Comma and Essex Skipper Butterflies and a number of moths. In the 1990 Dragonfly Atlas, 13 species of dragonflies were recorded in the area and this had increased to 21 in the new atlas covering records up to 2013. Barbara went through the new additions. Emperor Dragonfly was first seen in 2003. Study of the distribution maps suggest that it is possibly entering are from both Ireland and Northern England. Southern Hawker is well established further north around Inverness and Loch Ness but there are only a few records in Dumfries and Galloway as yet.
Migrant Hawker has spread north quite rapidly and has now extended into Dumfries and Galloway. Similarly Banded Demoiselle is spreading north and is now found at several sites in the area as is Keeled Skimmer. Broad-bodied Chaser has occurred but has not yet moved in and the other two additions were vagrants, Red-veined Darter and Vagrant Emperor.
Barbara also gave an update on the changes that have occurred for other species. New sites have been found for Hairy Dragonfly and the south-west of the area is the stronghold for the Variable Damselfly with indications that it is moving to higher elevations. Silver Flowe used to be a very good site for Azure Hawker but there are very few recent records and it may be lost.
David Clarke – The White-faced Darter re-introduction in Cumbria – the anatomy of a project
David said that his objective was both to describe the project and also to highlight lessons learned that may benefit other similar projects. However, species are different and so are individual circumstances. His guidance to others was identify a clear justification for the project, set up a small project team and talk to all the stakeholders so the situation and issues were well understood. The intended recipient site needs to be surveyed to check that it is suitable and any management work carried out. The project should extend over several years and the species should be monitored and progress evaluated over time. The justification for the White-faced Darter project was that there was only one reasonable site for them remaining in Cumbria at Scaleby Moss and this site was deteriorating and for various reasons this might continue. Foulsham Moss was a previous site for the species, but conifers had been planted and in this state it was unsuitable. The conifers have now been removed and work is ongoing to return the wet peatland habitat. Ponds similar in size to those that the species used at Scaleby had already been dug and hence it seemed to be suitable for the species.
The number of exuvia at the donor site were counted to check that transferring some larvae would not have an impact on the remaining population. This and other work allowed approval to be gained to undertake the transfer. The original intention was to transfer mature larvae but this changed to moving sphagnum moss containing a mix of eggs and larvae. This was introduced to certain of the new ponds at Foulshaw leaving other ponds to see if they were then colonised by the new population. Over 1000 exuvia were counted at Foulshaw Moss in 2015 with the highest count coming from a pond that the species was not transferred to and there is evidence that they have also spread to ponds on the reserve away from the group of newly dug ponds. The species has a two year life cycle and it is not clear whether there is any crossover between populations so continued monitoring is needed to see if there is a difference between odd and even years.
Foulshaw Moss has Emperor Dragonflies and Hobbies, both predators that do not occur at Scaleby and now has Ospreys breeding and this has restricted access to the reserve during the breeding season. The ponds are not open to public access anyway. The reserve is also getting wetter which makes monitoring more difficult. The species is still surviving at Scaleby Moss but the threats to it have not disappeared.
Pat Batty – Recording update.
Priority sites are a key interest. These are sites which hold one or more Red Data Book species, hold species with a very local distribution in Scotland or sites with a large number of species, the number has yet to be finally agreed but probably around 10. The database has been used to identify relevant sites but we have limited data on many of these. The aim will be to talk to relevant landowners with a view to helping them to maintain and possibly improve the sites. We also want to try to monitor priority sites where possible.
Northern Damselfly is of key interest. New sites have been found in Deeside, Perthshire and Insh Marshes. Work at Logierait Myres to create new pools may help this species where some existing pools have become overgrown. A number of new breeding sites have been discovered for Northern Emerald. The same is true for Brilliant Emerald and over 80% of sites for this species are on Forestry Commission land. Some new sites have been found for White-faced Darter but there are also fears that some existing sites are deteriorating. The situation with Azure Hawker is unclear. There was only one record of Emperor Dragonfly in 2014 and none in 2015. The expected increase has therefore not occurred and it is not clear why. 2015 was a good year for the migrant species Red-veined Darter.
Andrew McBride – Peatland Action – restoring peatland
Peatland Action is a major project to restore peatland in Scotland where 20% of land area is peatland. Work has been carried out at 150 sites to date with the aim of preventing loss of stored carbon by raising water levels in the peatland. While the original justification for the project was around reducing carbon loss, the aim has also been to improve habitat for conservation reasons. The aim has been to encourage creativity and involve people in the individual projects. Typical action has been to remove trees and scrub and to install dams on ditches and water courses to retain water. Removing trees and turning them into mulch is energy intensive. Various novel methods in addition to plastic sheeting have been used to create dams. Crushed glass in bags has been used on Shetland where shipping recycled glass south is relatively uneconomic. Another example of a creative approach was the use of old fishing nets to stabilise eroded peat and allow it to recover.
Peatland has been damaged by drainage and over grazing, with acid rain another potential problem. Funding for the project ended on 31 March 2016 but it is hoped that some work can continue, possibly with funding found for local projects and with more creativity to find ways to minimise costs.
Robert Fitt – Consequences of climate change driven range shifts on damselflies in NE Scotland.
Robert is undertaking a PhD at Aberdeen University on this topic and described some of his work and the results. He noted that the climate is changing and individual species occupy a zone that suits their requirements. If climate change alters the location of this zone then they have to move. DNA sequencing was carried out on 119 Blue-tailed damselflies from 12 sites. Quite long distance dispersals were indicated with a general trend of these being to the north. Species moving into an area may compete with the previously resident species. Part of his study was to visit ponds and monitor interactions between species. Observations suggest that where Blue-tailed damselfly increases, Emerald Damselfly populations decrease. Emerald Damselfly body size tends to increase when Blue-tailed Damselflies are present at the site. Competition between larvae tends to slow larval growth but they reach a larger size and this may explain the larger body size of the adults. Larvae were collected and observed in the laboratory. Blue-tailed Damselflies were found to be more aggressive in warmer conditions.
Peter Vandome – Dragonfly photography and emergence
Peter displayed some fascinating photos of dragonflies emerging but he has also recorded timing and other aspects of the process. He described the four stages of emergence. (i) leaving the water to the case beginning to split (ii) case split to abdomen out (iii) abdomen out to wings extracted and abdomen expanded (iv) to ready to fly. There has been some debate about stage iv as to whether it should be to first flight but as his later data showed the gap between being ready to fly and actually flying is highly variable and not a useful measure. His timing for the four stages on different species were rather longer than the literature states and he noted that this may be because the published information is based on data from the south of England where conditions are warmer.
He highlighted Azure Hawker where there is little information on emergence and he has tried to photograph the process. It is an interesting species in that it appears to behave as both a spring species with synchronised emergence and also as a summer species with a rather longer period of emergence in July. The limited number of records of exuvia tend to support this hypothesis. His attempts to find an emerging Azure Hawker were unsuccessful in 2015 but he did find a newly emerged adult on grass with its presumed exuvia close by.
Colin Hall – Glen Affric Peatland Restoration
Colin described his work in Glen Affric which was funded by the Peatland Action project described earlier. He hopes to continue with the work and is discussing aspects with the Forestry Commission. The aim will be to focus on work that can be carried out by volunteers without the need for expensive equipment or materials and hence requiring less funding. The work they have been carrying out is similar to the other peatland work that was described today. The work here should have benefits for Azure Hawkers and there is potential to link existing breeding pools with new pools to create a larger area of suitable habitat. A site to do this has been identified and there will be an expedition to the site on 10 July 2016 for which Colin is looking for volunteers to join him.
Daniele Muir – Hotspots and Community Engagement
Hotspots are places which are good for dragonflies, are easily accessible and near to communities. The intention is to identify places where people can see dragonflies and hopefully develop an interest in them and progress to recording them. We have already designated a number of hotspots. These are currently in the east and in the central belt in Scotland, mainly because work has been part funded by SNH and these were their priority areas. We hope to increase the geographic spread in 2016.
Scotstown Moor in Aberdeen was a new Hotspot in 2015 and there was a guided walk there which was well attended. Management work is being carried out here to improve the habitat. Trottick Mill Ponds in Dundee was also designated last year and a guided walk is scheduled for this year. Devilla Forest was a new hotspot and a venue for an identification and recording day followed by a walk where 6 or 7 species were seen and larvae found. A walk was carried out at Morton Lochs in NE Fife where around 50 Common Darters were on the wing. There is a plan for a dragonfly transect to be carried out here. Events and work have been held at other hotspots that were set up earlier.
Daniele described the work of the Scottish Group that started work last year. It is hoped that this group will help to liaise with landowners to maintain and improve habitats for dragonflies, particularly for priority sites. Priority sites and key species are a focus for SNH in 2016, although we have still to hear if there will be any funding. If anyone would like to monitor a priority site then she invited people to contact her and we can suggest potential sites near them. Daniele displayed a list of the events that are already planned for 2016 and she encouraged people to come along.
Jonathan Pickup – Summary
Jonathan rounded off the day by noting that there had been a number of themes highlighted during the day; recording and its importance, changes in distribution and peatland restoration (with particular reference to the use of plastic piling), reintroductions and engagement with people through citizen science and active volunteering. He warned us that we need to lobby SNH and Government to ensure they heard a balanced view from the conservation community and that the issues were not dominated by birds.