This month’s wildlife site is a name familiar to the group due to it constantly being in the local news due to the campaign to keep it as a valuable local wildlife site and not having sports facilities built on it.
The main site is a 61-acre urban meadow situated in the south-west of the borough and part of the River Brent Valley where it provides a green corridor with other sites. Immediately to the south is the rough grazing area of the Earl of Jersey field. The field borders Long Wood which has a good population of native Bluebells and in the wetter areas has locally rare plants such as Opposite-leaved Golden Saxifrage. To the east, we have the canal and River Brent.
During the Victorian period, it was very much a working farm. In 1925 it was sold to the London County Council for sports facilities but due to the war, it continued being used as a farm for a while. Sports facilities were finally built in the 1960s but when these were no longer used later last century the site rewilded itself and has evolved into an ecologically valuable site with a rich flora and fauna.
In addition to the main meadow, there is much valuable scrub around the edges with numerous mature Oaks. The area around the derelict buildings has its own distinctive flora dominated by the ubiquitous Buddleja and other plants such as Red Valerian, Rue-leaved Saxifrage, White Stonecrop and the recently colonising Narrow-leaved Ragwort from South Africa.
This area can be very good for several pollinating insects and is favoured by the likes of Painted Lady, Red Admiral, Peacock, Hummingbird Hawkmoth and many bees and hoverflies including our largest species the Hornet Hoverfly. In late summer large numbers of social wasps can be seen foraging honeydew from the sallow leaves.
The main meadow consists of areas of both neutral and acid grassland, the latter a priority habitat in the London area. In high summer this can look colourful with masses of Ragwort, Common Knapweed, Yarrow, Common and Sheep’s Sorrel (the latter a good acid grassland indicator) various buttercups, Creeping and Spear Thistle and Lady’s Bedstraw. In addition to these widespread (but important for the insect diversity) species are some very rare plants such as two small clovers, the Rough and Knotted Clovers and a dock relative, Copse Bindweed (not a true bindweed); the latter at its only extant site in Middlesex.
Probably the flagship species of Warren Farm is the Skylark which maintains a healthy population of these declining songsters. Warren Farm is the only remaining site in Ealing where this red-listed species breeds and can be seen regularly. A visit in spring to mid-summer should see lots of these birds flying around singing.
On passage and in winter the meadows also support small flocks of Meadow Pipits. A few Stonechats are regular on passage and sometimes over-winter, whereas Whinchats are exclusively birds of passage. Small finch flocks can be encountered, especially Goldfinch and Linnet, the latter another red-listed species, both of which breed around the edges of the area.
The horse field at the northern end often supports small numbers of Rooks at their only regular site in the borough along with Jackdaws and Pied Wagtails feeding around the horses and Starlings. In winter these may be joined by Redwings and Fieldfares while on passage it’s worth looking for species such as Wheatear and less regularly Yellow Wagtail.
Birds of prey are regular and it’s unusual not to see at least two or three species with Red Kite, Buzzard and Kestrel the most frequently seen, but Sparrowhawk and Peregrine are both regular with Hobby also possible in summer. Barn Owls feed over the meadow at dusk and two pairs of Little Owls live on or by the main site. Perhaps the rarest bird to be found here was a Wryneck several years ago seen by many of London’s birders.
The meadows are a butterfly magnet with large numbers of Meadow Browns, Gatekeepers, Marbled Whites and Small Skippers seen in summer while good populations of scarcer species such as Brown Argus, Small Heath and Small Copper can be found. Both White-letter and Purple Hairstreaks are known here and given their recent expansion we can hope to add Brown Hairstreak before too long. Moths include species such as Cinnabar, 6-spot Burnet, Dusky Sallow and Yarrow Pug.
In high summer the meadow is alive with the buzzing of grasshoppers (Meadow Grasshopper particularly abundant) and bush-crickets such as Roesel’s Bush-cricket while Emperor dragonflies hunt over the sward.
A highlight of late summer is the emergence of large numbers of Ivy Bees from the sandpits which forage on nearby Ivy. Many rare invertebrates have been recorded at Warren Farm including Rambur’s Pied Shieldbug and a spider new to Middlesex (Thanatus striatus).
Neil Anderson
