As mentioned in the August newsletter outward migration will be in full flow, especially in the first couple of weeks of the month. In addition to the scarcer species mentioned such as Whinchats and Wheatears, look for small groups of Swallows and House Martins passing over.

During September in the right conditions, there may be a steady stream of birds. It’s also the month when there is a small chance of something rare turning up, though these are more regular on the coast. We can cast our minds back three years when Warren Farm hosted a Wryneck for several days. Red-backed Shrike is another tiny possibility, as they’ve featured in a couple of neighbouring boroughs.

More expected are the flocks of Goldfinches which will be feeding on large clumps of thistles, knapweeds and teasels. There may well be some Linnets too, though these are more frequent in the outer parts of the borough.

Dragonflies can still be seen on the wing. Along with the numerous Common Darters and larger Hawker species, especially Migrant Hawker, it’s worth checking for a recent colonist, the Willow Emerald Damselfly. This first appeared in numbers around East Anglia in 2009 and a few years later appeared in the London area, where it is now widespread. They are often seen sitting in trees and other vegetation around water and, unlike other UK Odonata, lay their eggs in bark and stems, forming characteristic galls. The species is a relatively long emerald green body with pale wing spots and anal appendages. 

September is the season of Ivy flowering, and the sweet scent of the flower is often obvious before seeing it. In full flower, it is a magnet to so many insects, including Red Admirals, Commas, a range of flies (some of the Eristalis droneflies are often in number at Ivy), social wasps including Hornets and at night a number of moths can be seen feeding at it.

One particular species to look out for on it is the Ivy Bee, another recent colonist which was first identified in the UK in 2001. It has since spread considerably and is found in Ealing. Although strictly a solitary species they can breed in dense aggregations. One such locally is the sandpits at Warren Farm. Sometimes mating balls of numerous males trying to mate with a female can be observed.

Moth traps in September may yield some colourful moths with an autumnal hue, such as the various sallow species for example Common Sallow, Barred Sallow and Centre-barred Sallow, Red-green Carpet, Chestnut and the lichen-patterned Merveille du Jour.

Now is a time to see a wide range of fruiting fungi. One of the most distinctive species is the Fly Agaric with its red cap with white spots on it and a white stipe (stem). This iconic species has a mycorrhizal relationship with trees, most often with birches and pines. The species is hallucinogenic and featured in various pagan rituals.

What to see each month is written by EWG member and naturalist Neil Anderson.