This is simply to record something that makes me happy.
As the pandemic started, we were putting a new pond into our garden, intending to encourage wildlife. We made it with terracing at several levels, from a few centimetres deep at the edge, down to something around 30cm at the deepest point, to provide a variety of habitats. Just before lockdown started, we put in the plants: among these were irises and some long grasses, in the hope that eventually dragonfly nymphs could use these to climb up before emerging from the cuticle as adult dragonflies.
Last autumn, we realised there were dragonfly larvae in the pond. They were around 3.5cm long, possibly larvae of a hawker species. And in the last week, they have, as we'd hoped originally, begun to emerge and fly off as adults, leaving only exuviae as evidence of their passage.
Dragonfly larvae are ferocious predators, feeding on small animals, including tadpoles. Given the number of tadpoles we've had this year, I think our larvae must be well fed.
We've had about one per day for a week leave an exuvia clinging either to the grasses or the iris leaves. They probably emerge overnight, because no matter how early we go down the garden to try to see them in the process of emerging, they've always departed before we get there.
An exuvia on an iris leaf. This is the discarded cuticle of a dragonfly after the adult has emerged. If you look closely, you can see the rupture in the thorax where the adult came out.
However, last Sunday, it was raining hard first thing, and when we looked, there was a newly emerged dragonfly on an iris leaf, seemingly unable to fly off in the rain. It was a female southern hawker, shown here. By about 8 am it had disappeared, hopefully having flown off rather than having made a nice breakfast for a bird.
Side view.
Hawkers are known to emerge overnight, so that is consistent with us never seeing the emergence process.
It is only a small thing in the grand scheme, but walking down the garden in a verdant June to find a new exuvia is a wonderful start to the day.
BTW: if you are interested in dragonflies or damselflies, the British Dragonfly Society has an excellent, informative website. I can highly recommend the Field Guide to the Dragonflies and Damselflies of Great Britain and Ireland by Brooks, Cham and Lewington.
Update 2023-07-03: And still they keep coming
Exuvia on the underside of a water plantain leaf
Exuvia on an iris leaf. Space aliens, huh?
Here are a couple of recent exuviae photographed yesterday. I'd never expected this, but we've now had over 20 exuviae left behind as dragonflies have emerged in our small pond (we've now stopped counting). They've used several different species of plants: tall grasses, irises, water mint, plantains, and marsh marigolds. Mostly, we see a single exuvia each day, although one day we had half a dozen at once. When we put the pond in, I'd hoped we might get two or three dragonflies sometime, so to get maybe 10 times that number the first time around is amazing. As a famous man said, "I love it when a plan comes together".