What to look for this week - Damsels and Dragons
Published: 01 July 2020
A dragonfly in Shetland is a rare sight indeed but it can happen. Last year three were seen – on Foula, Papa Stour and near Stromfirth. Dragonflies are colourful, powerful beasts with amazing powers of sight, flight and manoeuvrability – well designed as an ultimate killing machine hunting down smaller insects in flight. They are though harmless to humans. They lay their eggs in water and have an aquatic larval stage that may last one or two years during which time the larval nymph moults several times as it gets larger, before climbing up some emergent vegetation and undergoing its final moult into a flying adult. Some species are long distance migrants and the Lesser Emperor on Foula last year will have originated from continental Europe. If you are lucky enough to witness one of these fighter aircraft fly by then do try and get a photograph which may help identify it.
The damselflies are very closely related to the dragons. The most obvious differences are their much slighter, more fragile appearance, and that they sit with their wings folded over their back, rather than spread out like a dragonfly. Two species occur in Shetland. The Common Blue Damselfly is found on wet blanket bogs and moorland lochs and pools in the central and north Mainland, and on Yell. We still don’t have a complete picture of its distribution so any observations would be very welcome. Our other species the Large Red Damselfly is a recent colonist found only at a pool near Voe. It does seem to be thriving there though and could spread elsewhere, so keep your eyes open. The Azure Damselfly has also been recorded in Shetland although this was at garden ponds where it seems likely that eggs or young larvae had been bought in with plants for the pond from south. These records are still very interesting though so do let us know if you see any.
Flying insects are one of the most sensitive groups to global warming with their powers of dispersal and short generation times so we might expect to get more dragonfly visitors in the years to come – it is worth remembering that seven species are resident just to the south in Orkney. These warm, calm days are certainly the best for finding our resident damselflies although don’t wait too long as the adults only last a few weeks during which time they must mate and lay their eggs in suitably wet places.
Paul Harvey, Natural Heritage Officer, Shetland Amenity Trust - July 2020
We hope you have enjoyed this blog. We rely on the generous support of our funders and supporters to continue our work on behalf of Shetland. Everything we do is about caring for Shetland's outstanding natural and cultural heritage on behalf of the community and for future generations. Donations are welcomed and are essential to our work.