The spring Bio Blitz for Costson Lane Nature Reserve took place on 29th April, and after what has felt like a very long winter, the weather gods smiled on us with glorious sunshine.
There was an early start for some keen birders staking out the main pond at 07:30, with highlights including Greenfinch and Blackcap. There were also promising signs that the Moorhens may be looking to start a nest on the site.
The main event started at 09:00 with a steady stream of visitors coming to the site throughout the day. Whilst we had plenty of regular Costons volunteers visiting, it was great to see some new faces, with at least ten people visiting the site for the first time.
Our moth trapping was less successful, with our two traps yielding only one Moth! There are definitely more moths on site so we think the previous night was not good for Moths. We will try again, but it shows the importance of doing regular surveys as you can never be sure how the wildlife will behave.
Among the highlights of the pond dipping was a female Smooth Newt (Lissotriton vulgaris) that was gravid with eggs. We saw these Newts in several of the ponds on the site (artificial and more natural); they seem to be thriving on the reserve. Once photographed she was released back to the pond she came from to continue creating the next generation of Newts. We also saw the first Damselflies of the year emerging, a sure sign that summer is on the way.
There is a healthy population of Slow Worms (Anguis fragilis) on site and they were certainly enjoying the chance to warm up a bit, with several spotted under logs and reptile mats. A few visitors had never seen one before so it was a pleasure to see how happy people were to see and learn about them.
Later in the day, we had Esmond Brown come on site with a powerful kit for extracting arthropods from the undergrowth. It works like a vacuum cleaner, gently hoovering up the creatures from a tussock of grass into a container, from where they can be tipped out onto a white tray for identification. This tool shows you how much life is packed into the reserve, with hundreds of Springtails, Spiders, Wasps, Beetles and bugs coming from the tiniest patches of plant growth. Esmond is a Spider expert so he was able to help us with several IDs including Walckenaeria cuspidata (sorry, no common name for this one) which hadn’t been recorded in Ealing before, and hadn’t been recorded in the county since 1987!
The event went on well into the evening, with a Bat watch carried out as dusk fell; although a calmer night for bats, we identified the Common and Soprano Pipistrelle Bat species feasting on flying insects over the pond and above our heads on the path. We finally wrapped up at 22:00 after a very long, busy but successful day.
The findings from our Bio Blitzes are being added to iNaturalist to maintain our records and confirm IDs where needed. We have only just started this process but we already have 728 observations online, representing a whopping 317 species. This is a fantastic result for such a small site (about 1 acre) and we are sure the numbers will just keep growing; this shows how even small parcels of land can be a haven for wildlife amidst the biodiversity decline.
Thank you to all those who came along and those who help out at Costons; you are invaluable to us and to the wildlife of Ealing and have made this a very special site indeed.