The extinction of the white-faced darter in Delamere, in 2003, meant that the forest lost both its flagship species and the forest’s emblem. So it was inevitable that a reintroduction would take place that not only assisted the species survival but also helped Delamere regain its identity.
Chris Meredith of Cheshire Wildlife Trust told Talk: Wildlife that, “White faced darters were found in Delamere until 2003. Records for the species date back to 1882 when they were present on a handful of sites in the area, however prior to drainage of the Delamere mosses, which began in earnest in 1812, they would have likely been even more widespread.”
Changed habitat drove extinction
So it looks like the writing was on the wall for this species in the early 1800s. Chris continued, “It was largely down to this historic drainage, and some undertaken more recently. This resulted in the fragmentation of the population and left remnant populations on only two sites, Abbots Moss and Black Lake. The Black Lake population was lost due to changes in water chemistry. Those from Abbots Moss were most likely affected by a lack of management of the pools, which were closing up with sphagnum growth and were heavily shaded by plantation forestry.”
Reassured by the successful re-introduction of the white-faced darter to Foulshaw Moss undertaken as a collaborative project between the British Dragonfly Society (BDS) and Cumbria Wildlife Trust from 2008 to 2014, Cheshire Wildlife Trust joined forced with the Forestry Commission to bring the darter back to Delamere.
Informed by the findings of “The Lost Meres and Mosses of Delamere”, Cheshire Wildlife Trust undertook a feasibility study in 2011. The study confirmed the forest contained habitat which, with minimal restoration, would be suitable for white-faced darter reintroduction. The restoration was completed as part of Delamere’s ‘Lost Mosses’ project and reintroduction started in 2013. Of course this was not only to justify using the species as the sites symbol, there was a more pressing need as habitat loss is putting real pressure on the species survival.
Dragonfly translocation has only been done once before in the UK
Chris explains, “The Mosses in Delamere have undergone varying degrees of restoration, and so with suitable habitat available it was deemed feasible to try and bring back the species. The white faced darter is classified as endangered on the UK red list. Remaining on only three breeding sites in England so the species’ conservation is seen as a national priority. The sites where it is currently found are limited in the extent they can increase in size – mosslands can only exist where they have formed, so surrounding farmland etc. cannot be converted into suitable habitat for them. So the reintroduction is vital for the survival of the species and will also help restore the natural heritage of Delamere.”
So the second ever dragonfly reintroduction in the UK – The first being the, previously mentioned, successful project in Cumbria also reintroducing the white-faced darter which has resulted in the best count ever for Foulshaw Moss with around 2000 individual exuviae counted this year – was underway.
The flight period of the white-faced darter runs from May to July. In advance of this larvae which are identified as being likely to emerge as adults that season are collected from the donor reserves, Chartley Moss and Fens & Whixall Mosses NNRs, for translocation to the Delamere Forest sites. The process will be repeated later in the season; this time collecting eggs and immature larvae. The receptor sites are then extensively monitored to gauge the success of the project and to monitor other species found around the pools.
When asked what impact the reintroduction may be having on the existing biodiversity, Chris replied, “We carry out dragonfly transects to monitor all species around the reintroduction site. We have not noticed any significant decrease in the numbers seen of any other species and white-faced darters fill a bit of a niche in the water, therefore I’m sure that they will be able to fit back into the dragonfly assemblage without much adverse effect on other species in the forest.”
Signs look promising
It is also re-assuring to hear that the project has not in any way been detrimental to the donor sites. In fact, numbers have risen significantly at both sites. Chris comments, “Over the course of the translocations we have been monitoring the numbers emerging from both of our donor sites. We monitor each site once a week during the white-faced darter emergence period. It has given a very good baseline of emergent numbers on each pool, which can be used to assess changes in population size in the future. Since the translocations began the number counted has increased, leading us to believe that the effect of the weather or development of vegetation is far more significant than the 5-50 larvae we take from each pool. The number we translocate is put into context by the total number we count at the donor sites, this year close to 4000.”
It may be too early to judge whether the project has been effective, but the signs look promising. Chris sums up, “Three years on from the first translocations it is very hard to say whether the reintroduction is a success. We have had plenty of positive signs, such as an increase in the number of exuviae (larval cases) found each year during the reintroduction. This year has also been the first year that I have been able to find mature larvae in the water ready to emerge next year, I also found some smaller larvae that will emerge in 2 years’ time. Monitoring the adults has been more difficult as we have had fairly poor late spring/early summer weather. We have seen mature white-faced darters laying eggs and holding territory, so we know they will return to the pool to breed.”
Let’s hope this reintroduction will be as successful as the one in Cumbria and that they both go from strength to strength.
With thanks to Chris Meredith.
Chris will be talking about the white-faced darter project at the BDS Annual Meeting on Saturday, 19 November 2016 at Nottingham Trent University.
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