Trends in British dragonfly species revealed in new atlas

Dragonflies are regarded as good indicators of wetland health and climate change. The new atlas shows how some species have expanded their ranges -- northwards in particular -- and apparently consolidated their previous ranges. In contrast, a few species have declined and/or retreated northwards, perhaps also resulting from warmer temperatures.

Sir David Attenborough, the British Dragonfly Society Patron who contributed the foreword to the new atlas, commented that the publication is "An invaluable distillation of the wisdom and experience of those who have spent many long hours watching these most wonderful of insects."

The new atlas covers the distribution of all 57 species of dragonfly recorded since records began, including all of the resident and regular migrant species, as well as all known vagrants -- individual insects appearing well outside their normal range -- up to 2012.

The Atlas completes a mapping project that lasted from 2008 to 2012 resulting in the gathering of nearly half a million records from over six and a half thousand people. The new dataset has been combined with over half a million previous records collected by dragonfly recorders since the 19th century.

The Atlas is more than just maps and distribution. It also contains an analysis of the trends in status of dragonflies in Britain and Ireland since 1980, and sections on habitats, environmental factors, phenology, recording and data collection.

The data in the atlas show:

• Fourteen (31%) of the 42 established breeding species have expanded their ranges, including the Scarce Chaser and the Red-eyed Damselfly, and appear to have benefited from a warming climate, together with a general increase in the number and quality of wetlands.
• Eight species (19%) have declined including the Scarce Blue-tailed Damselfly and the White-faced Darter. The reasons for this change are not fully understood, but may include climate change and/or habitat loss or deterioration.
• Three species were lost from Britain in the 20th century, but one of these has recently recolonised (the Dainty Damselfly in Kent).
• Five new species have colonised or attempted to colonise Britain since a previous atlas was published in 1996 including the Small Red-eyed Damselfly. Two new species have also colonised Ireland since 1990.
• No less than seven species have appeared in Britain and five species in Ireland for the first time since 1990, including the Willow Emerald Damselfly.
• The most commonly recorded species, with 115,375 records, is the Blue-tailed Damselfly, closely followed by the Common Darter with 103,251 records.
• The most widespread species was the Large Red Damselfly, which was found in 80% of the hectads -- 10 km x 10 km Ordnance Survey grid squares -- from which dragonflies were recorded during 1991-2012.

Steve Cham of the British Dragonfly Society said, "On behalf of the British Dragonfly Society, I would like to pay tribute to the huge effort made by thousands of recorders and volunteer data collators in gathering data for the atlas. Dragonflies have captured the imagination of people for centuries, but we never envisaged that so many people would contribute records. This staggering response has enabled us to assess changes to the distribution of dragonflies over time. We hope that this publication will inspire people to continue to contribute to this long-term study."

Dr Helen Roy from the Centre for Ecology & Hydrology leads zoological recording for the Biological Records Centre, the UK's national focus for terrestrial and freshwater species recording. She said, "This atlas represents inspiring contributions from many, many volunteers across Britain and Ireland. Dragonflies are charismatic and popular insects but they also provide an important insight into the ways in which our environment is changing. So not only is the atlas another wonderful example of citizen science but it is also providing valuable scientific evidence."