While dragonfly may be admired by some and feared by others, they are important indicators of the health of the environment, writes Dick Ahlstrom
Ireland's 32 native dragonfly species star in vivid living colour in a stunning publication from the Ulster Museum. It provides a definitive baseline of existing dragonfly species and their distribution, information that speaks not just of these striking insects but of the quality of their habitat and the waters that support their life-cycles.
The Natural History of Ireland's Dragonflies is written by Dr Brian Nelson and beautifully photographed by Robert Thompson. "The dragonfly Ireland project was a mapping project," says Nelson who is also Ulster Museum's curator of fresh-water invertebrates.
The four-year project, completed with this publication, involved organising a small army of 250 recorders who submitted about 13,000 records of dragonfly sightings across the island. Details of what was seen, where and when were taken down and catalogued for this book, which was a North-South cooperative project supported by Dúchas, the North's environment and heritage service and the science division of the Ulster Museum.
"We went through all the old records as well," says Nelson. "There was an Atlas done in Britain and Ireland in 1990, but Ireland was never covered comprehensively." This new publication now corrects that situation and provides solid baseline data for any subsequent review of the dragonfly in Ireland.
"Dragonflies are beautiful, fascinating animals in their own right but they are also valuable for assessing water quality and habitat quality," says Nelson. "They are indicators of the health of the environment."
The museum and its partners agreed a four-year study programme and a funded a publication at its conclusion. "We had a lot of people who had contributed to different records in the past," Nelson explains, and the promoters ran ads in magazines to encourage more people to report on the dragonflies they saw. "We got a terrific response," he adds.
"They are very active insects, unlike most. They are open and flamboyant. They can be a quite aggressive species and are predators," says Nelson, so finding people willing to participate was not difficult.
Adult dragonflies are on the wing over the summer from May until September, but this stage is comparatively short compared to the insect's larval stages, says Nelson. Larvae live in ponds for anything from nine months to five years before emerging as adults to lay eggs and complete their life-cycle.
The one common feature is proximity to water although some species lay their eggs in plants rather than ponds so there is variety.
"We do not have a rich fauna here," says Nelson. "Dragonflies are mostly a tropical insect."
Even so, the new study identified three new species here since the 1990 survey. These include the blue emperor, Ireland's largest dragonfly, the autumn hawker and the yellow-ringed emperor. These three have spread northward almost certainly as a result of the warmer conditions brought about through global warming, Nelson believes.
There were no losses, the collected data indicated, he added. The two rarest Irish species, the Moorland Emerald and Downy Emerald, found only in Killarney National Park, continue to survive there.
Thompson has been photographing dragonflies and damselflies for years, and many of his pictures show the insects in their typical habitats, says Nelson. There are also many images of the insects in their larval stages.
The Natural History of Ireland's Dragonflies is available from the Ulster Museum for £20 (€30). Copies can be purchased in the Ulster Museum shop or may be ordered by phoning the Museum at 0044 28 9038 3000. Postage is additional.
The national dragonfly survey website is: www.habitas.org.uk/dragonflyireland