Environmental Statement volume 4 - Chiltern Evergreen3

Chiltern Line September 2009Bat Dusk and Dawn Survey1.0 IntroductionBackground1.1 ERM are producing a Nature Conservation chapter for an Environmental Statement on behalfof Chiltern Railways (CRCL) to assess the upgrade Scheme for the existing railway betweenBicester an d O xford. Du ring a pr eliminary as sessment of the Scheme several structureswithin the proposed S cheme b oundary we re a ssessed as having potentia l for ro osting,commuting and foraging bats, therefore bat surveys were recommended.1.2 In July 2009, Keystone Environmental Ltd was instructed by ERM to conduct surveys for b atroost potenti al of 3 brid ges (B 7 (SP 525 14 3), B8 (SP 524 21 4), & B16 (S P 502 073 )), 1viaduct (V2 (SP 517 136)) and a tu nnel (B12 (SP 4 49 101)) and to conduct emergence andactivity surveys next to 1 bridg e (B2 (SP 584 216)) and 3 strips of woodland (W6 (SP 507127), W8 (SP 499 088) & W9 (SP 502 081)). Access was not available to one other building,the Grain Sil o, located at Water Eaton, howev er a p revious bat survey had be en carried outfor a plannin g application for this site. The bat survey indicated that there were no bat semerging fro m the buildi ng and b ats were not u sing the flood ed un derground a rea as ahibernation site (Mitchell, pers coms).1.3 Following the roost potential surveys, mist net surveys and further detector work was carriedout at Wolvercote Tunnel (B12 (SP 449 101)) where swarming and a potential hibernation sitewas identifie d. This rep ort incl udes the fi ndings o f the addition al detecto r work and mi stnetting at this location.1.4 During bat surveys it was established that large bat maternity colonies are present at WythamWoods SSSI, located approximately 1.7 km from the Scheme boundary.Aims and ObjectivesThe primary aims of the bat surveys are to inform the Nature Conservation Section of theEnvironmental Assessment.1.5 In order to inform the Environmental Sta tement the aims of the surveys we re to ascertain thefollowing:Presence/absence of bat roostsGeneral level of bat activity associated with the various featuresIf further surv eys or a European Protect ed Species (EPS) licen ce would be requiredto ensure legal complianceIf mitigation measures are necessary to reduce significant impactsSite Characteristics1.6 The Chiltern line ru ns north of Oxford a nd stretches from Oxford station to Bice ster Junction,approximately 20 kil ometres to the north-east. T he site com prises mo stly the rail wayembankment supporting a mosaic of habitats, but with the largest percentage being scatteredKeystone Environmental 1