Last week, we had some interesting happenings in our pond bed out the front of the visitor centre. It has been in place now for about two years, and has really settled into the surroundings. The local wildlife has discovered it (though some were introduced, like the great diving beetle that I caught in the moth trap one evening!), and it has become a wonderful home for wildlife. In particular, it has become a home for dragonflies. I’m sure most of you will know that the dragonfly life-cycle begins once the adults lay their eggs in water. The eggs then hatch, and the larvae, or nymph, will walk or swim around its watery habitat, usually for one or two years, but in some species this can be up to five years. During this time, they feed on other aquatic insects and sometimes even tadpoles and small fish! Once they are ready, they climb up a suitable bit of vegetation, usually on the edges of a pond, and start the magical transformation from nymph into a beautiful dragonfly. This is not something that is seen very often, although we do often find the empty discarded case or exuvia (shown below).
However, over the last week, there have been at least a dozen emerging dragonflies, which I managed to get a few photo's of.
The fully developed adult within the larval case pumps fluid into its body causing it to swell. This splits the larval cuticle, and the adult pushes its way through the hole.
The adult rests for a while, still partly in the case while its legs harden. Then it fully emerges and begins pumping its wings full of fluid to expand them. Once its wings have expanded, it pumps the fluids into the abdomen to expand it. Hawker dragonflies generally wait until morning to take their maiden flights, although the ones in the pond bed seemed to disappear after a couple of hours. The adults will then tend to fly away from water, only returning a week or so later when the are mature enough to find a mate and begin the life-cycle again.
One thing about emerging dragonflies is that it is actually quite hard to tell what they are until they've fully dried off, so apologies to everyone who I said that they were hairy dragonflies....
They were in fact four-spotted chasers!!
Emma, our other warden even spotted this damselfly emerging, which are even harder to identify when they've just emerged!
I think this is a large red damselfly, but happy to be corrected!!
The whole emergence period can take up to two or three hours depending on the species, and during this time, the adult is very soft and vulnerable to predation by birds, or even insects like ants. We do currently have a hungry family of pied wagtails very close by, so I'm hoping that the newly emerged dragonflies have escaped their attention!
They didn't escape the attention of these photographers though...
So next time you visit, have a peer into the pond and see what you can find!
Image credits: All Katherine Puttick