Thanks to volunteer Phil for his report, photos and reflections on the new dragonfly species arriving at Pulborough Brooks...
I am currently sitting at my computer sheltering from the hot weather as the UK bakes in another heatwave and the land is feeling the effects of a drought. It is becoming easier to link the greater prevalence of events like this to a changing climate. However, while these somewhat worrying heatwaves are forcing us to adapt, there are some interesting and exciting wildlife sightings that are driven by this too. My latest one was on 12 August.
Dragonfly aficionados may think I am about to discuss the willow emerald which has been seen several times in the last 2 years, particularly by the Dipping Platforms. However I wrote a piece for the blog about this species in 2021 which can found at this link.
https://community.rspb.org.uk/placestovisit/pulboroughbrooks/b/pulboroughbrooks-blog/posts/willow-emerald-damselflies-the-wait-is-over
I can now add that mating has been observed by our dragonfly survey team this year, so it seems these damselflies are here to stay.
On Friday at Redstart Corner pond I was surprised in this very dry summer to see a small amount of water left. However, with water present I was not surprised to see a blue-eyed hawker because my colleague Graham has reported this species there at least twice this year and once last year. This dragonfly was very busy patrolling round the pond but perched very briefly to allow me to take this shot.
I spent some considerable time trying to photograph it in flight, but it was very busy and the view is somewhat restricted by the pondside vegetation, so this was the only usable shot I managed.
It does at least show the blue eyes.
In fact the whole insect shows a truly beautiful mid blue colour which indicates a male and I had to stay and admire it for quite some time. My colleague Graham tells me he thinks the markings are slightly different from the specimen he photographed there a few weeks ago so with only one specimen recorded last year it seems there have been at least 2 in 2022.
Another name for this species is the southern migrant hawker but I prefer not to use this as it is too easy to confuse with 2 other species of hawker, i.e. the southern and the migrant. However the name is descriptive in a rather different way as it is mainly a species of Southern Europe and the Mediterranean, and has always had a tendency to migrate northwards. It seems likely that climate change is encouraging this spread.
There have been very occasional records in the UK going back many years, but the first breeding records were at sites around the Thames Estuary in 2010. Since then there has been a gradual increase in records in the South and it seems that river valleys may be providing a highway for the dragonflies to spread from the coast. For example, sightings seem to be quite common now in the Ouse Valley in East Sussex and the recent sightings at Pulborough Brooks suggest that the Arun Valley is perhaps being used in a similar way.
For comparison its worth considering the similarly sized and marked migrant hawkers here. These are on the wing in late Summer and early Autumn so now is a good time to look for them and they are commonly seen at Pulborough Brooks This is itself a migratory insect which is constantly looking to expand its range and has always been widely spread in Europe. But it started colonising Britain in the 1940s and after a few years became one of our resident dragonflies with numbers being swelled each year by insects from Europe. Might this have been a very early indicator of climate change? It is hard to be sure but it is a reminder that there may have been some indicators of a changing climate long before humanity woke up to the issue.
This photo shows a male migrant hawker which also has blue and black markings but there are also brown spots mixed in and the eyes only have a hint of blue.
It is a good looking insect in its own right but does not present the same intense blue aspect that is the main feature of the male blue-eyed hawker.
We have not yet recorded female blue-eyed hawkers, but female migrant hawkers are common. Both however are very similarly marked brown and yellow insects and may be difficult to tell apart. This photo shows a female migrant hawker laying eggs into a grass stem at Redstart Corner Pond a few years ago.
Note the very long anal appendages at the end of the abdomen which are not quite so long in the female blue-eyed hawker.
As yet I am unable to supply a photo of a female blue-eyed hawker but I hope that situation may be rectified in future years. Hopefully sightings of these colourful insects will increase in the same way as the willow emerald damselfly sightings.