Wednesday, 29 March 2017

“One of the rarest bats in western Europe” is found at Straitgate


Aggregate Industries' consultants found "at least eleven bat species" 7.133 when they surveyed the Straitgate Farm site in 2013; "bat activity was concentrated along hedgerows and plantation edges" 7.202.


Barbastelle is listed as Near Threatened by IUCN. It is protected under Annex II of the Habitats Directive.
Barbastellus requires a complex mosaic of habitats to support foraging, roosting and commuting behaviour… It is unknown whether the amount of habitat in the UK is sufficient to support a viable population of the species.
The Bat Report accompanying AI's application to quarry Straitgate concludes:
Of the rarer species recorded… The most significant of these rarer bats is barbastelle… the east edge of the site… consistently recorded barbastelle in June, July, September and October. In addition to species-rich hedgerows a damp ditch is present near here, habitats which may support micro-moth species which barbastelle specialise on. 4.0
It is 2km of these species-rich hedgerows - that provide commuting routes for local populations of Barbastelle and other bats - that AI plans to remove.

DCC had said in its Reg22 request to the previous application that:
Before any works begin the applicant MUST evidence that bat flight lines around the site are maintained (and any important habitat for barbastelles protected or compensated for)… habitat MUST be in place before works start.
AI responded by saying:
The highest level of barbastelle activity recorded within the site was 0.12 [registrations per hour] which equates to approximately one bat every eight hours… Therefore there is no requirement to provide compensation habitat for this species... 4.19
But the raw survey data clearly shows 0.23 rph at Location 4 in July and 0.21 rph at Location 5 in September, and in any case, the Ecology Report makes clear that "...it is impossible to accurately assess the number of bats using the survey area and surrounding locale..." 7.158.

Despite this, and despite its rarity, AI’s consultants, "tempered by professional judgment" 7.158, downplayed the importance of this species, giving Barbastelle, Greater and Lesser Horseshoe bats, a "County" Level of Value. Advice from other ecologists dispute this conclusion.


The Anabat detectors used here for static monitoring have been found inadequate at detecting horseshoe bats, as this Proof of Evidence makes clear:
Horseshoe, Bechstein’s and long-eared bats all have very quiet calls which make them difficult to detect… the types of bat detectors used by the surveyors were not high quality (see Adams et al. Do you hear what I hear? Implications of detector selection for acoustic monitoring of bats) and had very directional microphones (meaning that a horseshoe bat would need to fly towards the microphone in order to be heard)…. The static detector survey using an ANABAT detector was simply inadequate to provide useful information.
AI cannot assume therefore that "Greater horseshoe was extremely rare despite suitable habitat..." 4.0. It is likely that the site’s importance for bats has been under-reported. Barbastelle, Greater Horseshoe and Lesser Horseshoe score 32 in Table 7-8 which is of "Regional" value.