Environmental Statement volume 4 - Chiltern Evergreen3

Chiltern Line, Oxford - Bicester August 2009Otter and Water Vole Report3.0 Survey ResultsField Survey3.1 No evidence of Water Voles was found during the field survey although many areas containedgood areas of emergent vegetation, which is a habitat preference of this species (Strachan etal, 2006), and suitable banks for burrowing.3.2 Mink footprints and scats were found on a limited number of sites, namely the River Cherwell.3.3 Incidental observations made on site included Signal Crayfish, deer, Badger and Kingfisher.3.4 Although evidence of Otters was not found in all the stretches, evidence of Otter activity wasrecorded th roughout the survey a rea. No holt s were record ed within 5 0 metres of thecrossing points, or any where in th e surveyed sections, alth ough there were a numb er o fpotential holt sites foun d throughout the stret ches surveyed. Th e summary of Otter use o nthe stretch es su rveyed, a nd tho se stretches that were n ot surveyed due to no la ndownerpermission b eing provide d, are sho wn on the su mmary plan (refer to Drawing Numbers:9761/9/6wor01 to 9761/9/6/wor08.) The details of each stretch are provided below.3.5 Upper Langford Brook: This is a small stream, formally in a rural setting, but now be comingsurrounded by the expan sion of Bice ster. It is the northern most stretch that was surveye d,but is crossed a num ber of times by t he Chilt ern Railway line as it proceed s south fro mBicester. 500 metres either side of the crossing point was surveyed.3.6 The Upper 500 metres of this 2 met re wide stream passes through semi-improved grasslandon the true right ban k a nd woo dland o n the tru e lef t bank. The lowe r 5 00 metres pa ssesthrough managed fields on the true right bank and scrub on the true left bank, beyond whichis unm anaged tall gra ssland, befo re passing u nder G avray Drive, whe re t he chan nel i ssurrounded by public open space, with grassland on the left ba nk and a hedge-line on theright, beyond which is further grassland.3.7 The main crossing under the rail b ridge is a 3 metre square brick culvert with a 1 metre wideledge on either bank and a silt bar centrally. Only rat field signs were recorded at this point .Gavray Drive bridge is a box culvert with three relief pipes, 2 on the right bank, 1 on the left.Badgers were using these dry pipes.3.8 The trees and shrubs consist of Crack Willow, White Willow, Ash, Hawthorn, Blackthorn andGuelder Rose. The banks are dominated by Common Nettl e, Great Willowherb andbindweed, while the channel has Starwort sp., River Water Crowfoot and Algae. A Kingfisherwas observed twice, plus Meadow Brown, Small White, Tortoi se Shell, Spe ckled Wood andPeacock butterflies, Blackbird, Bullhead and Stickleback.3.9 Tubbs Crossing Stream: This is a small st ream of about 1 metre in wi dth and only 5centimetres flow depth. Above the crossing the 20 metres surveyed (before it was culverted)had 1 stone wall bank and 1 soil ba nk, which sw apped from left to right fo r the second 10metres before passing through a 1.5 metre high brick lined culvert. Below the crossing pointthe 50 metre section surveyed ran between an old hedge-line with public open space on theKeystone Environmental 5