|OS grid reference:||SP 685 245|
|Nearest postcode:||MK18 2FQ|
|Usual work:||Hedgelaying, bridge building|
Calvert Jubilee Nature Reserve is a BBOWT (Berkshire, Buckinghamshire and Oxfordshire Wildlife Trust) nature reserve that was once an old clay extraction pit for the brick industry. Over the last 50 years, the 200 hectare standing open water habitat has become a haven for large numbers of over-wintering wildfowl and waders. The reed beds provide ideal habitat for the scarcely seen bittern, and the nutrient poor clay-capped land around the lake provides the right conditions for wildflowers and good numbers of rare butterflies including the grizzled and dingy skippers.
Flora and Fauna
The deep lake is surrounded by reeds and thorny scrub with a large open area to the north, where flora such as the bee orchid and the common spotted orchid can be found. There is also a small copse of poplars, where wood pigeons and woodpeckers can often be found. Other fauna at the site includes willow, hawthorn, elder and brambles.
A large number of wildfowl have been recorded at the site. These include birds often seen in country gardens, although many in decreasing numbers, such as the blackbird, blue tit, great tit, robin, collared dove, bullfinch, starling, house sparrow, greenfinch and chaffinch. Among the resident and over-wintering waterfowl species recorded at Calvert Jubilee are the snipe, great cormorant, common sandpiper, eurasian wigeon, dunnock, eurasian coot, grey heron, tufted duck, long-tailed duck, pochard, redshank, mallard, great crested grebe and little grebe. Around the site other species such as the meadow pipit, marsh tit, rook, brambling, green woodpecker, wood pigeon, carrion crow, black-headed gull, whitethroat warbler, goshawk, nightingale, pheasant and lesser black-backed gull have often been observed.
A large number of butterflies have been spotted around the standing water at Calvert Jubilee. These include several species of skipper, such as the small skipper, Essex skipper, large skipper, dingy skipper and grizzled skipper. Other species recorded at Calvert Jubilee include the rare orange tip, the small copper, small white green-veined white, large white, brimstone, common blue, comma, speckled wood, meadow brown, ringlet and small heath.
BBOWT perform a large number of conservation tasks at Calvert Jubilee, including coppicing and the construction of tern rafts on the water's edge. The latter provide safe breeding areas for the wildfowl. Areas of shallow water and mud banks have been created at the edge of the lake to encourage waders. OCV have assisted at the site with various tasks such as building a footbridge, scrub clearance, habitat pile creation and conservation hedgelaying.
Calvert Jubilee is 6 miles east of Bicester, near Calvert. From Bicester, head south on the A41. From the A41, head north past Grendon Underwood and drive through Edgcott. Carry on north until you reach a crossroads with Charndon on the left, Calvert on the right and lakes including Grebe Lake in front of you. Go right to Calvert. Calvert Jubilee will be on your right. There is a small car park for three cars. Note that a permit is required to visit the site, so the best way to see it is to come along to an OCV task.