Wildlife

Conservation status of the Trap Grounds

In March 2015 Oxfordshire County Council, advised by the Thames Valley Environmental Records Centre, officially designated the western half of the Trap Grounds (a mosaic of woodland, ponds, grassland, and scrubland) as a Local Wildlife Site, to complement the LWS status already accorded to the eastern (reed bed) half of the site. The designation of the entire site is based on the diversity of its habitats, and especially its important habitats of reed bed and wet woodland; its communities of rare or uncommon species; its connectivity with Port Meadow and the Canal; its value for the appreciation of nature; and its value for learning.

This pocket of urban wilderness supports a remarkable diversity of wildlife. Thanks to local photographer Nicola Devine, we have photographic records (dating from 2015 to the present) of all the birds, mammals, invertebrates, reptiles, amphibians, flora, and fungi named below.

Birds

Foremost among the birds of the site is the elusive Water Rail , which is less often seen than heard: lurking in the reeds, it occasionally gives vent to a series of grunts, yelps, and squeals, known as ‘sharming’. It is resident throughout the year and breeds here. It is not known to breed anywhere else in Oxford, and there are very few sites in the whole county where it does so regularly.

In summer the waterlogged sedge and reed beds sustain several pairs of Reed Warblers. Their deep nests are wonderfully woven around several reed stems, and decorated with the white fluffy seedheads of willow. The Reed Warblers share the wetland habitats with Reed Buntings, Mute Swans, Mallards, Teal, Moorhens, Coots, Grey Wagtails, and Kingfishers.

The scrubland and woodland are home to Green Woodpeckers and Great Spotted Woodpeckers. … Tree Creepers make their nests behind the bark of Crack Willows. … Blue Tits, Great Tits, and Coal Tits make use of the bird boxes installed by the Friends, while Long-Tailed Tits prefer the willows along Frog Lane (where Goldcrests successfully reared chicks for the first time in 2019). … Blackcaps and Chiffchaffs call incessantly from the earliest days of Spring, but by early Summer they are outnumbered by the raucous, quarrelling Jackdaws that flock around the site. … Wrens, Robins, Dunnocks, and House Sparrows lurk in the undergrowth, while Bullfinches, Goldfinches, and Greenfinches flaunt themselves brazenly on the edges of the meadows.

Summer visitors include Spotted Flycatchers and Lesser Spotted Woodpeckers, and Winter visitors include Fieldfares, Redwings, and Siskins.

Mammals

Our most significant resident is the Water Vole . This species has undergone a long-term decline in Britain, disappearing from 94 per cent of its former sites. It is protected in the UK under the Wildlife and Countryside Act, 1981, and designated as a Priority Species under the UK Post-2010 Biodiversity Framework. Remarkably for a semi-urban site such as ours, there is a small community of Water Voles in the Trap Grounds (and another one living alongside our site, on the bank of the canal).

Not to be confused with Water Voles, Water Shrews can sometimes be seen foraging along the stream or the Frog Lane ditch. Foxes are ever present but not often seen, as they slip away at the slightest disturbance. Likewise Badgers. A family of Muntjac deer live here, and a Roe Deer has recently (2019) been seen. Bank Voles and Wood Mice thrive in the rough grassland. On warm summer evenings the occasional Pipistrelle or Noctule Bat zooms over the reed bed in pursuit of aerial insects (but too fast to be caught on camera – even by Nicola).

Invertebrates

Of the 33 species of dragonfly and damselfly known to breed in Oxfordshire, 22 have been recorded on the Trap Grounds. The County Dragonfly Recorder (www.stephenburch.com/dragonflies/OxonGuide) describes the Trap Grounds as “A delightful small site, with an impressive species list for its size. Early in the season, Hairy Dragonflies can be seen, and on one notable occasion a wandering Clubtail was seen for a few days. Later on, the Dragonfly Pond is notable for emerging Southern Hawkers (June/July). Other notable sightings in the hot 2018 summer included Emerald Damselfly and Beautiful Demoiselle. Good numbers of Brown and Migrant Hawkers are around later in the season.”

There are 57 resident species of butterfly in the UK, and by June 2019 Nicola Devine had photographed at least 24 of them on the Trap Grounds, including most notably the Brown Hairstreak and Silver Washed Fritillary; and at least two dozen species of moth, most notably the Emperor, Red-tipped Clearwing, Red-Green Carpet, and Eyed Hawkmoth.

Reptiles and Amphibians

In the reed beds live harmless Grass Snakes. Although they prefer the damper parts, they will venture out to curl up on an exposed rocky outcrop to sunbathe. In early Spring the ponds heave with mating Frogs and Toads. Smooth Newts are more furtive, but may be found lurking in damp places around the site. Our most notable reptile is the Slow-worm (legless lizard). In 2017 a five-month weekly survey found a total of 335; and on a single day in September 2018, 47 adults and juveniles were counted.

Flora and Fungi

The Trap Grounds cannot boast any outstanding botanical rarities, but the wide variety of flowering plants provide food (nectar, pollen, berries, and seeds) for birds and insects, and shelter for a range of other organisms. Interesting wetland species include Celery-leaved Buttercup (Ranunculus sceleratus), Gipsywort (Lycopus europaeus), and Ragged Robin (Lychnis flos-cuculi). The woodland supports a surprising number of Spurge Laurel shrubs (Daphne laureola, usually a sign of ancient woodland). The scrubland contains the greatest variety of species, including inevitably some ‘garden escapes’, such as Stinking Hellebore (Helleborus foetidus) and Buddleia (Buddleja davidii), an excellent source of nectar for butterflies. The grassland contains many native wild species, such as the semi-parasitic Hay-rattle (Rhinanthus minor) and Great Mullein (Verbascum thapsus).

Interesting fungi photographed since 2015 include Earthstar (Geastrum triplex), Chicken of the Woods (Laetiporous sulphurens), and Dog Stinkhorn (Mutinus caninus).

Header photograph credit Nicola Devine