HABITAT REGULATIONS ASSESSMENT OF
Core Policy10 LAND WEST OF WELLS
MENDIP DISTRICT COUNCIL
LOCAL PLAN
July 2012
(amended November 2012)
This report was prepared by Larry Burrows, Ecologist - Strategic Planning, Somerset County Council on behalf of Mendip District Council, as the 'competent authority' under the 'Habitat Regulations' 2010
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Contents
1. Introduction ...... 4 Background ...... 4 The Habitats Regulations Assessment Process ...... 5 2. The Proposed Site Allocations ...... 6 3. Characteristics and Description of the North Somerset and Mendip Bats SAC 9 Component Sites...... 9 Determining Reasons for Designation...... 9 Site Condition...... 9 Foraging Ecology of Greater Horseshoe Bats...... 10 Foraging Ecology of Lesser Horseshoe Bats ...... 12 Conservation Objectives ...... 13 Vulnerability...... 13 4. Test of Likely Significance...... 15 Use of the Proposed Allocation Sites by Horseshoe Bats ...... 15 Habitats Present...... 18 Horseshoe Bat Diet ...... 19 Likely Effects on Horseshoe Bats from the Proposed Site Allocations ...... 21 5. Counter Acting Measures...... 22 Introduction ...... 22 Street Lighting ...... 23 Loss of Habitat - Methodology...... 24 Offset Assessment for Haybridge North ...... 29 Offset Assessment for Haybridge South...... 31 6. Conclusion ...... 36 References ...... 37
3 1. Introduction
Background 1.1 The requirement for ‘Habitat Regulations Assessment’ (HRA) of plans or projects is outlined in Article 6(3) and (4) of the European Communities (1992) Council Directive 92/43/EEC on the conservation of natural habitats and of wild fauna and flora (known as the ‘Habitats Directive’). This requirement has been implemented into UK legislation under the Conservation of Habitats and Species Regulations 2010. The purpose of HRA is to ensure that protection of the integrity of European nature conservation sites (Natura 2000 sites).
1.2 The definition of ‘HRA’ is simply an assessment, which must be ‘appropriate’ to its purpose under the Habitats Directive and Regulations. According to the Habitats Regulations 2010, regulations 61 before authorising a plan which is likely to have a significant effect on a European site but is not connected to the management of the site the Council shall assess the implications for the site in view of its conservation objectives.
1.3 Natura 2000 sites include Special Protection Areas (SPA) classified under the EC Birds Directive 1979 and Special Areas of Conservation (SAC) and candidate Special Areas of Conservation (cSAC) designated under the EC Habitats Directive 1992, and, as a matter of Government policy, all Ramsar sites, designated under the Ramsar Convention on Wetlands, are treated as if they are fully designated European Sites for the purpose of considering development proposals that may affect them.
1.4 North Somerset and Mendip Bats SAC is designated for greater and lesser horseshoe bats. The Wookey Hole component site is also designated nationally as a Site of Special Scientific Interest (SSSI) for the same reason.
1.5 This report concerns the potential effects on the integrity of the North Somerset and Mendip Bats SAC from Core Policy 10: Wells City Strategy in the Local Plan, and resultant development. The proposed site allocations are located west of Wells at Haybridge and lie just over 1 kilometre from the Wookey Hole roost site. Survey work since the HRA of the Mendip District Council Local Development Framework Core Strategy (Preferred Option) January 2011 has shown the presence of both species on the development site. This new data would also require the amendment of the Bat Consultation Zone as shown in that report.
1.6 The greater horseshoe is one of Britain’s most rare and endangered bat species. It is estimated that numbers have declined by 99% in Britain since the turn of the last century, with only c.6000-7000 now being left,
4 confined to South Wales and South West England. Caves are used by the species for roosting throughout the year.
1.7 Lesser horseshoe bats are a widespread but rare species in central and southern Europe. The South West of England and Wales support one of the largest concentrations.
The Habitats Regulations Assessment Process 1.8 Stage 1, the ‘significance’ test, of the Habitats Regulations Assessment process, acts as a coarse filter for all proposed plans or projects which are not directly connected with or necessary to the management of the site (whether or not the effect is likely to be adverse or beneficial) so directing (English Nature, 1999) conservation interest of the site should be at the forefront of decision-making.
1.9 The preliminary considerations of the HRA process is to consider and record the features for which the site has been selected and the conservation objectives for the site. In all cases, the following should be recorded:
• What are the SAC’s qualifying interest features? • What are the SAC’s conservation objectives? • What other relevant site information is available? e.g. site (SSSI, NNR, SAC/SPA, European Marine site) management plans; list of operations which may cause damage or deterioration.
1.10 A ‘ likely significant effect ’ is any effect that may reasonably be predicted as a consequence of a plan or project that may affect the conservation objectives of the features for which the site was designated, but excluding trivial or inconsequential effects. Permanent reductions in habitat area or species populations are likely to be significant unless they are very small scale. (English Nature, 1999) In some cases the loss of 0.1% an area of habitat has been considered significant by the Secretary of State (Hoskin & Tyldeslay, 2006). The magnitude of the impact should be considered in judging what is significant.
1.11 Natural England (English Nature, 1999) set out considerations for carrying out Stage 1 of the HRA process, the test of significance. The principle guidance states that ‘ Consideration of ‘likely significant effect’ will have practical and legal consequences and must be based on sound judgement and bear scientific or expert scrutiny .’ In addition, ‘ Proposals having no, or de minimis , effects can be progressed without further consideration under the Habitats Regulations although reasons for reaching this decision must be justified and recorded .’
5 1.12 However, Natural England (English Nature, 1999) state that, ‘… if a clear judgement cannot be made on the basis of available information, then an appropriate assessment [Stage 2 of the HRA process] will be required ’.
1.13 EC Guidance (2000) sets out a number of principles as to how to approach decision making during the process. The primary one is the ‘Precautionary Principle’, which requires that the conservation objectives of Natura 2000 sites should prevail where there is uncertainty. In other words if the answer is ‘don’t know’ an adverse impact is assumed. This is the case throughout the HRA process
1.14 Stage 1, the ‘test of significance’ should consider the following:
1. What potential hazards are likely to affect the interest features? Are the interest features potentially exposed to the hazard?
2. Is the potential scale or magnitude of any effect likely to be significant alone or in combination with other projects or plans?
1.15 Under the Habitats Regulations, where, ‘…regulations 48 and 49 [regulations 61 and 62 in the Habitats Regulations 2010] apply, the competent authority may, if they consider that any adverse effects of the project on the integrity of a European site would be avoided if the planning permission were subject to conditions or limitations, grant planning permission or, as the case may be, take action which results in planning permission being granted or deemed to be granted subject to those conditions or limitations .’ Therefore this report will set out those conditions and limitations whereby planning permission could be granted if Mendip District Council is so minded and if it is considered that no residual significant effects on the SAC would result. These conditions and limitations are in practice mitigation or counteracting measures that would ensure that conservation objectives of the SAC are not subject to adverse effects.
1.16 Where it is considered that residual significant effects remain at the end of Stage 1 then a Stage 2 Appropriate Assessment would need to be carried out.
2. The Proposed Site Allocations
2.1 The Mendip draft core strategy (Feb 2011) identifies land to the west of Wells as a future housing growth area. Two areas of land have been
6 promoted for development in this area and are being considered as a strategic site allocation. These are shown below in figure 1. Land at Haybridge North is being promoted by Strategic Land Partnerships and land at Haybridge South is being promoted by Charles Church and Taylor Wimpey Homes.
Figure 1: Proposed Site Allocations
2.2 The proposed development strategy [See Figure 2] for Haybridge North shows that the three fields comprising the site would all be developed for housing and associated infrastructure. Additionally a school is required by Somerset County Council within the proposed site.
2.3 The proposed development strategy for Haybridge South [See Figure 2] requires that at least three fields within the site area would be developed for housing, and associated infrastructure. A second access road is likely to be required from Glencott Road north of Elfrida Terrace. The HRA also assesses a larger area to inform the Council’s long-term options (see paras 5.45-5.50).
7 Figure 2: Potential Development Strategy (Strategic Land Partnerships)
8 3. Characteristics and Description of the North Somerset and Mendip Bats SAC
Component Sites 3.1 The component sites for the North Somerset & Mendip Bats SAC are:
• Compton Martin Ochre Mine SSSI • Banwell Caves SSSI • Banwell Ochre Mine SSSI • Brockley Hall Stables SSSI • King’s Wood and Urchin Wood SSSI • The Cheddar Complex SSSI • Wookey Hole SSSI
3,2 Compton Martin Ochre Mine, Banwell Caves, Banwell Ochre Mine, Brockley Hall Stables and King’s Wood and Urchin Wood SSSIs are all located in the geographic area administered by North Somerset Council. Compton Martin Ochre Mine is within 300 metres of the Somerset border. Banwell Caves is within 2 kilometres and Banwell Ochre Mine just over 2 kilometres.
Determining Reasons for Designation 3.3 This site in south-west England was selected on the basis of the size of population represented (3% of the UK greater horseshoe bat Rhinolophus ferrumequinum population) and its good conservation of structure and function, having both maternity and hibernation sites. This site contains an exceptionally good range of the sites used by the population, comprising two maternity sites in lowland north Somerset and a variety of cave and mine hibernation sites in the Mendip Hills.
3.4 The limestone caves of the Mendips provide a range of important hibernation sites for lesser horseshoe bat Rhinolophus hipposideros . The Cheddar Complex component site supports a number of possible bat hibernacula and a single maternity roost. The maternity roost is located in the show caves. At Wookey Hole the roost site is located off the show caves.
Site Condition 3.5 Based on the tables for the equivalent Site of Special Scientific Interest the condition of the affected components, by % of site, as of May 2012 is as follows:
9 Table 1: North Somerset and Mendips Bat Site Condition SAC component site Favourable Unfavourable Unfavourable Unfavourable Destroyed, recovering no change declining part destroyed Banwell Caves 100 0 0 0 0 Banwell Ochre Mine 0 0 100 0 0 Brockley Hall Stables 100 0 0 0 0 Cheddar Complex 54.40 45.60 0 0 0 Combe Martin Ochre 0 0 100 0 0 Mine Kings Wood and 78.29 54.09 4.92 4.62 0 Urchin Wood Wookey Hole 100 0 0 0 0
3.6 Counts of greater and lesser horseshoe bats using the roosting sites at the Wookey Hole SSSI were made in February 2010 and are as follows:
Wookey Total Greater Horseshoe: 60 Total Lesser Horseshoe: 42
Badger Hole Total Lesser Horseshoe: 10
Hyena Den Total Lesser Horseshoe: 1
Rhino Hole: No bats
On 29 January 2006 there were 24 Greater Horseshoe (GHS) and 33 Lesser Horseshoe (LHS) in Wookey, none in Hyena Den or Rhino Hole, and 1 GHS and 7 LHS in Badger Hole.
3.7 The trend for the winter period is an increase. No summer counts are available.
Foraging Ecology of Greater Horseshoe Bats 3.8 The top five feeding areas for greater horseshoe bats include:
• pasture with cattle as single stock or part of mixed stock (38.6%); • ancient semi natural woodland (16.6%); • pastures with stock other than cattle (10.3%); • meadows grazed by cattle in the autumn (9.4%); and • other meadows and broadleaved woodland (4.9%).
10 3.9 These habitats are not used according to the fore listed proportions throughout the year but change with the seasons. Woodlands and pasture adjoining wood are used in spring and early summer. As summer progresses, feeding switches to areas further away and tends to be fields used for grazing cattle and other types of stock. Meadows that have been cut and where animals are grazing are also used. (Ransome, 1996)
3.10 Within 1 kilometre of the roost the presence of permanent grazed pasture is critical for juvenile greater horseshoe bats. A high density of grazing animals should be present giving high presence of dung. Within the remainder of the roost foraging range grazing regimes can be more flexible provided adequate pasture is available. Longer swards benefit the larvae of noctuid moths. (Ransome, 1996)
3.11 A balance of woodland and pasture of about 50% and 50% provides optimum resources for greater horseshoe bats. Grassy rides and glades in woodland increase the range of food and provide opportunity for perch hunting. (Ransome, 1996; Bontadina et al, 2002)
3.12 A tall thick hedgerow is a very efficient way of producing a maximum level of insect prey using a minimum land area and important creators of physical conditions that enhance insect concentrations and reduce wind speeds for economical hunting flight (Ransome, 1996).
3.13 ‘Hostile’ habitats for greater horseshoe bats are arable and urban areas (Ransome, 1997)
3.14 Larger hedgerows are required for commuting and also foraging by greater horseshoe bats. Continuous lines of vegetation of sufficient height and thickness to provide darkness when light levels are still relatively high are needed for commuting bats. (Ransome, 1996)
3.15 Greater horseshoe bats travelling away from the roost towards foraging grounds do so along distinct flight paths, which are strictly adhered too. Paths may change during the summer season as foraging switches from woodland to pasture. Up to three main flight paths radiating in different directions can be used by a single colony, with varying proportions of the colony using different ones through a single summer, possibly as different foraging areas become profitable. The majority of flight paths (about 70%) run along the edges of woods, woodland rides or tall hedges, only rarely crossing open fields. Open fields are crossed after dusk on dark nights, when they will fly fast and head for cover. They travel about 1 metre away from vegetation edges. (Ransome, 1996)
3.16 Greater horseshoe bats will cross gaps in flight lines of up to 12 to 15 meters but are not crossed unless dark (Billington, 2000). Greater
11 horseshoe bats are averse to streetlights and artificial lighting (Billington, 2000; Outen, 2002; Bat Conservation Trust/Institute of Lighting Engineers n/d).
3.17 Hawking over pasture occurs at low levels of between 0.6 and 1.5 metres height and close (within 4 metres) to woodland edge or hedgerows (Ransome, 1996; Jones & Billington, 1999).
Foraging Ecology of Lesser Horseshoe Bats 3.18 The primary foraging habitat for lesser horseshoe bats is broadleaf woodland where they often hunt high in the canopy. However, they will also forage along hedgerows, tree-lines and well-wooded riverbanks .’ (Schofield, 2008)
3.19 Lesser horseshoe bats are primarily a woodland feeding bat using deciduous woodland or mixed coniferous woodland and hedgerows. It has been found that habitats that were most important contained a high proportion of woodland, parkland and grazed pasture woodland, combined with linear features, such as overgrown hedgerows. Woodland with watercourses has more importance. Broadleaved woodland predominated over other types of woodland and was shown to be a key habitat for the species. In the core foraging areas used by bats woodland accounted for 58.7 ± 5.2% of the habitats present. (Barataud et al, 2000; Bontadina et al, 2002)
3.20 Knight (2007) showed that broadleaved woodland was used most by lesser horseshoe bats where tree cover was 75% – 90% of the core feeding area. In addition, pasture was used where there was 25% tree cover.
3.21 Occasionally bat activity is concentrated in fields containing cattle where bats forage directly over cattle. However, the same lesser horseshoe bats forage little, if at all, over the same pasture immediately after the cattle are removed (Cresswell Associates, 2004).
3.22 Lesser horseshoe bats are susceptible to loss of linear features, such as mature hedgerows, which act as commuting routes between roost sites and foraging areas and indeed to other roost sites. Lesser horseshoe bats avoid crossing open areas; they will cross open areas at the narrowest point; they will cross roads where the tops of trees touch but in the open do so by flying very close to the ground (approx. 1 metre). Gaps as little as 10 metres could prevent movement along a flight line (Schofield et al, 2002; Brinkmann et al, 2003). At Ciliau SSSI lesser horseshoe bats only crossed the River Wye when fully dark (Schofield et al, 2002). Lesser
12 horseshoe bats have been observed crossing roads where the tops of trees have touched (Brinkmann et al, 2003). Hedgerows below 2 metres high and certainly below 1 metre high would be avoided (Limpens & Kapteyn, 1991).
3.23 At Hestercombe House individual lesser horseshoe bats were recorded in late July/early August travelling distances of 5 and 6 kilometres to feeding areas (Billington, 2005). Bontadina et al (2002) considered that a large colony size increases the foraging range of individuals, and conversely that the average foraging distance in smaller colonies might be even smaller. In the Bontadina et al study (2002) a colony of 300 bats had a maximum foraging range of 4.2 kilometres whereas at Hestercombe there is a maximum foraging range of 6 kilometres for a colony of c.150 bats. Individual lesser horseshoe bats located within the Ciliau SSSI colony of c.157 bats commuted to a maximum of 2.695 kilometres to hunt (Schofield et al, 2002). Individual home ranges of females from maternity colonies are between 12 and 53 hectares in area (Boye & Dietz, 2005).
3.24 In Bavaria a female lesser horseshoe bat was recorded as using 7 different foraging areas over three nights. The size of foraging area varied between 3.6 and 18.2 hectares (mean 8.4 hectares). (Holzhaider et al, 2002) This would translate as a mean of 58.8 hectares of feeding area being used per bat within the area of the landscape used by the colony. Tessa Knight suggests that lesser horseshoe bats generally have individual territories with relatively small overlap (Pers. Comm. Jan, 2011).
3.25 The lesser horseshoe bats also feed throughout the winter, depending on temperature (Williams 2001: in Bat Conservation Trust/BMT Cordah, 2005). In England radio-tracking of bats revealed that they foraged on average to a maximum distance of 1.2 kilometers from the hibernation site. One bat traveled to an absolute maximum distance of 2.1 kilometers. The winter foraging range appears to be approximately half the area covered in the summer months. (Bat Conservation Trust/BMT Cordah, 2005)
Conservation Objectives 3.26 The conservation objective for the European feature of the Wookey Hole SSSI is ‘ to maintain, in favourable condition, the habitats for the population of Greater horseshoe bat ( Rhinolophus ferrumequinum ) and Lesser horseshoe bat ( Rhinolophus hipposideros )’.
Vulnerability 3.27 The Bat Conservation Trust/ BMT Cordah Ltd. (2005) set out the main factors considered to be causing loss or decline in greater horseshoe bats to include:
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• Reduction in food availability, particularly loss of old pasture, through agricultural intensification;
• Loss, damage or fragmentation of foraging habitat and flyways, through the conversion of mosaics of habitat containing woodland, hedgerows and pasture to arable land, particularly the conversion of hay meadows to silage which is cut three times a year rather than once. This is an example of intensification rather than land use change;
• Lack of suitably connected foraging habitat (a mosaic of pasture, hedgerows and woodland) within the foraging zone up to 14km radius of breeding roosts essential for the maintenance of greater horseshoe bat populations; and
• Loss or disruption of key flyways between different roosts (the greater horseshoe bat is a wide ranging species).
3.28 Greater horseshoe bats will cross gaps in flight lines of up to 12 to 15 metres but are not crossed unless dark (Billington, 2000).
3.29 Current factors considered to be causing loss or decline in lesser horseshoe bats include:
• Loss, damage or fragmentation of important foraging habitats, such as deciduous woodland, and connecting linear features such as hedgerows and tree lines
• Lack of suitably connected foraging habitats (a mosaic of deciduous woodland, hedgerows and tree lines)
3.30 Gaps as little as 10 metres could prevent movement of lesser horseshoe bats along a flight line (Schofield et al, 2002; Brinkmann et al, 2003).
3.31 Both horseshoe bats species are sensitive to artificial lighting, such as from street lamps (Outen, 2002; Bat Conservation Trust /Institute of Lighting Engineers, 2008).
3.32 Stone (2009); Stone et al , (2009) has shown that lesser horseshoe bats are disrupted from flying along hedgerows by introduced artificial light levels above 0.5 Lux. It was also found that continued disruption increased the effect, i.e. lesser horseshoe bats do not become habituated to the presence of artificial lighting. This would therefore permanently affect their behaviour possibly having a significant effect on use of flight lines accessing feeding areas. Lacking data to the contrary it is
14 considered that greater horseshoe bats would react in the same way.
3.33 Natural England’s design guidance produced for greater and lesser horseshoe bats with regard to lighting recommended that artificial light levels should not exceed 0.1Lux and where flight lines cross roads these should be kept dark (Natural England, 2010)
3.34 Many night flying species of insect are attracted to light, especially those lamps that emit a ultra-violet component and particularly if it is a single light source in a dark area. As well as moths, a key prey item for greater horseshoe bats, a range of other insects can be attracted to light such as craneflies, a primary prey species for lesser horseshoe bats. Studies have shown that the slower flying broad winged species such as horseshoe bats generally avoid streetlights. In addition, it is also thought that insects are attracted to illuminated areas from further afield. This is thought to result in adjacent habitats supporting reduced numbers of insects. This is a further impact on the ability of the light avoiding bats to be able to feed. ( Bat Conservation Trust /Institute of Lighting Engineers, 2008; pers. comm. Emma Stone, University of Bristol, 2009)
4. Test of Likely Significance
Use of the Proposed Allocation Sites by Horseshoe Bats 4.1 Surveys for bats have been carried out for the Haybridge North site by Phil th th Quin MIEEM in the summer of 2011 on three occasions, 24 July, 10 August and 20 th August on transect surveys using Pettersson D240X time expansion detector. Weather conditions were good.
4.2 Lesser horseshoe bats were detected on all three occasions with 3 passes being recorded in July and 2 each in August. Greater horseshoe bats were detected on the two site visits in August, with 2 passes and 1 pass being recorded respectively. The locations of the records are shown in Figure 3.
4.3 Where greater horseshoe bats are present Natural England recommend that surveys take place once a month for two evenings per month between May and September as horseshoe bat foraging activity varies with the season for development sites of over 1 hectare within 4 kilometres of a roost site. (Mitchell-Jones, 2004). Therefore, the current surveys only confirm presence.
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Figure 3: Horseshoe Bat Records (Haybridge North), 2011.
4.4 No bat surveys have been carried out by the consultants appointed to assess the Haybridge South site. Therefore, it must be assumed, lacking evidence to the contrary, that the site is being used by horseshoe bats where suitable habitat structure allows access
4.5 No surveys have been undertaken for the cycle route along the disused railway line that runs east west between the two sites. It is assumed that this corridor is also used by horseshoe bats.
4.6 To support the assessment of the use of the proposed allocation site areas `by horseshoe bats the likely flight lines used by horseshoe bats in commuting and foraging through the locale has been considered and drawn in Figure 3. The existing records above are used and as a guide it is assumed that hedgerows below 2 metres high and certainly below 1 metre high would be avoided (Limpens & Kapteyn, 1991).
16 Figure 3: Potential Flyways of Greater Horseshoe Bats
4.7 In addition to the flight lines the former railway bridge at the western end of the cycleway may host a night roost for both species of horseshoe bats. Night roosts are also particularly important, enabling bats to exploit feeding areas, which would not otherwise be possible due to energetic constraints. These roosts are used by horseshoe bats for resting, grooming, eating or sheltering in bad weather. Importantly some bats, especially pregnant females, can extend their foraging range from the maternity roost by using such roosts. Night roosts can be found in a wide range of structures, such as church porches, garden sheds, agricultural buildings and underground sites (Schofield, 2008). Knight & Jones (2009) found that more than 75% of bats used night roosts away from the maternity site and that up to five different night roosts were used by individuals. Surveys for the development of the sites should also assess the bridge for night roosting opportunities.
4.8 There is a possibility that the site is also entered through the old railway bridge. However, for the purposes of this assessment it is considered unlikely as the commuting route to the west of the bridge is disrupted by the access road and parking built along the course of the old railway to service the scrap yard and sewage works. It is not known if this area is also lit at night by security lighting.
17 4.9 It is considered that the A371 would form a barrier to horseshoe bat movement to the south of the Haybridge South site (See Figure 3 above)
Habitats Present Haybridge North 4.10 Habitat surveys of the site have been carried out by Sunflower International Ecological Consultancy over a period from July 2005 to July 2011. The site consists of three arable fields, a very small spring fed pond surrounded by a copse and along an area of scrub along the railway embankment running along the southern boundary of the site. The area of the site is in total approximately 9 hectares (ha) measured using OS Mastermap.
4.11 The three fields are bounded by hedgerows. These include species rich hedgerows, some of which are trimmed, and tall gappy hedegrows. Species found in these hedgerows include hazel, hawthorn, blackthorn and other woody species. The area of these is calculated using aerial photographs and OS Mastermap. The amount of hedgerow on site amounts to approximately 0.42ha As well as providing commuting structure hedgerows would also provide prey species for horseshoe bats (See Figure 3).
4.12 The arable fields have been used to grow winter wheat since 2008. However, wide grassy margins have been retained between the crop and the hedgerows. These grassy margins would provide prey for horseshoe bats as would the pond (approximately 0.01ha) and the area of the scrub adjacent to the railway embankment (approximately 0.17ha). The amount of arable field loss would therefore amount to approximately 8.37ha less the grassy margins. Therefore the net amount is 8.1ha, assuming the margins to 1 metre wide with an area of 0.27ha.
Haybridge South 4.13 A survey of habitats was carried out in December 2010 by Aspect Ecology. It was found that the site consisted of three semi improved grassland fields in the south and east of the site. These are cattle grazed and of low botanical interest. However, due to the presence of cattle they are likely to have a value for horseshoe bats. The area of these three fields is in total is 8.08ha. There is an area of scattered scrub on the northern edge of these fields of about 0.1ha, which gives a net total of 7.98ha
4.14 The other fields are arable fields surrounded by 1 metre grassy margins. Winter wheat was being grown in the autumn of 2008. The total area of arable is approximately 8.80 hectares less the 1 metre rank grass margins. The totals length of grassy margin is approximately 2.6km which
18 equates to about 0.26ha. Net total of arable land is therefore approximately 8.54ha.
4.15 The fields are divided by hedgerows and are largely unmanaged standing 3 to 4 metres high except the hedgerow and eastern boundary which is 1 to 2 metres and heavily managed. Hedgerows are often gappy at the bottom. Species recorded in the hedgerows are hawthorn dominated but include hazel, and occasional dog-rose, elder, field maple, elm, dogwood, blackthorn, bramble, ivy and rarely spindle and Guelder-rose. All hedgerows qualify as UK BAP priority habitat except for four. Total length is about 1197 metres, or assuming a width of 2 metres 0.24 hectares and 243 of poor hedgerow about 0.02ha.
4.16 In addition to the internal hedgerows access to boundary hedgerows will also be affected by the construction of the distributor road on the northern site. These appear to be of poor quality for horseshoe bats but nonetheless would contribute to the prey biomass for the site. The length of these is 830 metres or 0.08ha.
4.17 There is a small narrow watercourse which enters the site from the disused railway to the north and crosses the site to exit on the western boundary which is heavily managed and therefore of low ecological value. The length of this water course is about 460 metres and is about 0.5 metre width 0.023 ha.
4.18 There are also field ditches totalling about 310 metres in length or about 0.015ha. These are considered of low ecological interest and are sometimes dry but may function with the hedgerows as local wildlife corridors.
4.19 There is a pond with shallow banks and partly bounded by hedgerow. It is heavily cattle poached and littered with disused tyres and is likely not to contain water all the time.
4.20 It is assumed that although the plantation woodland would remain. However, the presence of the A371 would reduce its quality as feeding habitat as there is likely to be displacement due to traffic noise (Schaub et al, 2008). The area of this plantation is 0.41ha.
Horseshoe Bat Diet 4.21 A primary food source for greater horseshoe bats is Melolontha , which fly in May and June normally. Melolontha feed on deciduous leaves, potentially in the trees and scrub around the sites. However, females oviposit in short grazed pasture, which is present in the Haybridge South site. The larvae feed on roots of grass, herbs, shrubs and trees.
19 (Ransome, 1996; Ransome, 1997).
4.22 Another primary species group in the diet of greater horseshoe bats are moths (Lepidoptera) which could use habitats on both sites including the grassy margins around arable fields. From faecal analysis the main species caught by greater horseshoe bats are common noctuids. Species such as heart and dart ( Agrostis exclamationis ), dark arches ( Apamaea monoglypha ), large yellow underwing ( Noctua pronuba ) and lesser yellow underwing ( Noctua comes ) are all important. These are available as a group from May to September. (Ransome, 1996) Moths can tolerate a wide range of open land habitats, including gardens, waste ground, fields and meadows; they feed on a variety of herbaceous plants and grasses. These species are likely to make use of the field, woodland edge, scrub and hedgerows on and around the site. Longer swards benefit the larvae of noctuid moths. (Ransome, 1996). Winter wheat is also known to support a number of Noctuid species (Alford, 2011).
4.23 Of the secondary prey species hunted by greater horseshoe bats the site possibly supports tipulids. All tipulid species lay their eggs in short grass and suitability depends on management and dampness of the site, many species preferring damp woods or crops in which to oviposit. (Ransome, 1996)
4.24 Lesser horseshoe bats have one of the most restricted diets of any British bat species (Vaughn, 1997). Due to their small body size they cannot cope with large prey, such as cockchafers. By comparison they eat smaller moth species than the greater horseshoe bat (Beck 1995: in Boye & Dietz, 2005). A single bat can consume in excess of 3000 insects in one summer night (Kelleher, 2004).
4.25 The diet of the lesser horseshoe bat consists mostly of Diptera of the crepuscular sub-order Nematocera. Families of Nematocera Diptera recorded in the diet include Tipulidae (crane-flies), Ceratopogonidae (biting midges), Chironomidae (non-biting midges), Culicidae (mosquitoes), and Anisopodidae (window midges). Lepidoptera (moths), Trichoptera (caddis-flies) and Neuroptera (lacewings) are also eaten. (Vaughan 1997; Boye & Dietz, 2005).
4.26 A faecal study of lesser horseshoe bats from Hestercombe House SAC carried out by Knight Ecology (2008), showed seven major prey categories comprised over 70% of the diet: Tipulidae, Anisopodidae, Lepidoptera, Culicidae, Hemerobiidae, Trichoptera and Ichneumonidae. Hemerobiidae, the brown lacewings, are a major prey item with high frequency in the faecal samples, particularly early in the year (May) with occurrence lowers in July and August when large numbers of other prey items, such as Tipulidae and Lepidoptera occur.
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4.27 Small moths (Lepidoptera) occur in a variety of grassland habitats, hedgerows and are likely to be present in such habitats across the two proposed allocation sites. Ichneumonidae are parasitic on the larvae of Lepidoptera. Ophian luteus is notably nocturnal and occurs in a wide variety of habitats including farmland. (Chinnery, 2005)
4.28 The presence of cattle is a factor in access to foraging for lesser horseshoe bats (Cresswell Associates, 2004). Dung flies have been shown to be an element of the diet (Knight, 2008). The presence of pasture is indispensable to the larval stage of development for certain species (Tipulids), which form a significant part of lesser horseshoe bat diet (Motte & Dubois, 2002; Boye & Dietz, 2005). Therefore, the grazed pasture present on the Haybridge South site is likely to be used by lesser horseshoe bats
4.29 Chinery (1986), states that Hemerobiidae are mainly found in woodland and hedgerows. It appears that this is a particularly important prey item for lesser horseshoe bats when other major prey items are not so abundant. Hedgerows and scrub is present across both proposed allocation sites.
4.30 There are a number of ditches and ponds of poor quality across both proposed allocation sites which may provide habitat for Culicidae. Adult Anisopodidae are found on foliage or around flowing sap in or near damp places; sometimes seen in swarms.
Likely Effects on Horseshoe Bats from the Proposed Site Allocations 4.31 The assessment does not take into account counter-acting or preventative measures by way of mitigation at this stage.
4.32 The areas designated for housing development in the Potential Development Strategy would result in loss of commuting and / or feeding habitats for both species of horseshoe bats. Street lighting and other casual lighting, roads and open areas would effectively prevent access to horseshoe bats in areas assigned to housing development and its associated infrastructure including roads, cycle and footpaths and amenity grassland.
4.33 Where hedgerows are retained within development areas it is considered that these could also be lost to horseshoe bats due to street and other lighting and that available mitigation such as louvres would not result in maintaining existing light levels. Without louvres streetlights will emit I Lux of light at a distance of 15 metres from the column with a mounting height of 10 metres and for 13.1 metres with a mounting height of 8 metres (Emery, 2008). Therefore a 5 metre column is likely to produce 1 Lux at
21 just over 10 metres distance. Natural England advises that light levels be kept to 0.1 Lux within new development where horseshoe bats occur (Natural England, 2010).
4.34 In addition to direct loss of habitat, street lighting and other artificial lighting sources is likely to draw in invertebrate prey from habitats on site and the surrounding countryside (Outen, 2002; pers. comm. Emma Stone, University of Bristol, 2009). Moths are reported to be attracted to streetlights from 60 to 200 metres away, depending on the species, and may be responsible for dramatic declines in numbers over the past fifty years (Outen, 2002). Therefore, there would probably be a reduction in the prey available to horseshoe bats in the undeveloped fields adjacent to the built development.
4.35 It is considered that a significant effect cannot be ruled out due to loss, degradation or severance of commuting and / or feeding habitat used by horseshoe bats as a result of development in the proposed allocation sites based on the available evidence .
Assessment of In Combination Effects 4.36 The Habitats Regulations require competent authorities to make an appropriate assessment of any plan or project which is likely to have a significant effect on a European site, either alone or in combination with other plans or projects. This test appears in regulations 20, 24, 48 and 60 and is therefore implicit in many other regulations. It is derived from the obligations of Article 6(3) of the EC Habitats Directive. (English Nature, 2001)
4.37 A search of the Mendip District Council Planning website (http://planning.mendip.gov.uk/northgate/planningexplorer/generalsearch.a spx) revealed no firm current applications that are likely to act in combination with the proposed allocation sites to alter the assessment above. The redevelopment of the Thales site adjacent to the Haybridge North site to the east is unlikely to support greater or lesser horseshoe bats. The entire site is former industrial units, hard surfacing and amenity grassland.
5. Counter Acting Measures
Introduction 5.1 This chapter considers measures that will negate the likely significant effects identified in Chapter 4. The potential adverse effects identified are:
22
• Loss of feeding habitat directly from built development;
• Reduction in prey availability and behavioural changes from the effects of street lighting.
5.2 The following sections set out counter acting measures recommended to ensure that there are no significant effects on the populations of horseshoe bats in the Wookey Hole component of the North Somerset and Mendip Bat SAC. The Haybridge North allocation is expected to accommodate 187 houses (Tetlow King sketch layout, Dwg. SKL-01, 22.12.2102) plus a primary school requested by Somerset County Council and the Haybridge South allocation about 150 houses with recreational land included (pers. comm. Andre Sestini, Mendip District Council).
Street Lighting 5.3 The following principles apply to both application sites to reduce the effects on the behaviour of greater horseshoe bats with regard to commuting and to minimise loss of prey resource through attraction to street lamps.
5.4 Greater horseshoe bats are known to be averse to street lighting (Bat Conservation Trust /Institute of Lighting Engineers, 2008; pers. comm. Emma Stone, University of Bristol, 2009). Somerset County Council is likely to specify standard street lamps 5 metres high with high pressure sodium lamps on all estate roads and to formal footpath and cycle routes. To avoid light spill into areas of habitat used by greater horseshoe bats street lamps should be fitted with louvres. These will direct light away from habitat areas reducing the length of spill behind the lamp at 1 Lux from about 15 metres to 9.5 metres (Emery, 2008). For light levels to reduce to 0.5 Lux or even 0.1 Lux the distances would be exponentially more.
5.5 Where the backs of gardens are adjacent to greater horseshoe bat habitat close boarded fencing should be installed to act as a barrier to security or recreational lighting (which cannot be controlled).
5.6 Street lights and other artificial light sources are known to attract insects out of the surrounding countryside reducing prey availability to light shy bats (Bat Conservation Trust /Institute of Lighting Engineers, 2008; pers. comm. Emma Stone, University of Bristol, 2009). The ultra violet (UV) component of streetlights especially attracts insects, including moths and craneflies. Therefore, lamps should be fitted with UV filters ( Bat Conservation Trust /Institute of Lighting Engineers, 2008). This should effectively reduce the area of impact of the street lighting on the prey species of greater horseshoe bats so that effect is not significant.
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5.7 The above requirements for street and other lighting would need to be included in policy if the allocations are to come forward to the Local Plan.
Loss of Habitat - Methodology
Introduction 5.8 Biodiversity offsetting can be an important method for ensuring a ‘no net loss’ of important ecological features as a result of development. To demonstrate ‘no net loss’ offsets need to be clearly defined, transparent and measurable. (Defra, 2009) This method is used to calculate the amount of habitat required to be created or enhanced to offset the loss or severance of habitat incurred by the proposed development sites whilst maintaining ‘favourable conservation statuses’ of the horseshoe bat populations at Wookey Hole SSSI. Offset habitat creation can be developed on site (mitigation) or may need off site land to be developed (compensation), possibly in more than one location.
5.9 Habitat Suitability Indices (HSI) has been used in the United States and Canada since the early 1980s as way of assessing the impacts of development on species' populations and distributions. In addition, they have been used to predict what offset habitat needs to be created to maintain species' populations. HSI have also been used in conservation planning and has proven useful in the USA for such as screening permits in the Southeast, for the comprehensive planning of refuges in the Northeast, and for land acquisition with state and non-government partners 1.
5.10 The process assumes that the suitableness of habitat for a species can be quantified - the HSI. The overall suitability of an area for a species can be represented as a product of the geographic extents of each habitat and the suitability of those habitats for the species.2 The method is adapted from and uses data from the Somerset Biodiversity Offsetting project (Somerset County Council, 2012)
5.11 The two proposed allocations are assessed separately as the development of each may not be timed so that habitat created on one site would benefit the other. Currently each proposed allocation has a different prospective developer. Therefore, they would need to stand alone so that one can be brought forward independent of the other site.
1 http://www.fws.gov/r5gomp/gom/habitatstudy/Gulf_of_Maine_Watershed_Habitat_Analysis.htm 2 http://www.fort.usgs.gov/Products/Software/HEP/
24 Habitat Suitability Index 5.12 Basic assumptions are made in developing a HSI in that habitat influences animal distribution; and HSI models predict habitat suitability not occurrence or abundance (Dijak & Rittenhouse, 2009).
5.13 A decimal system of 0.1 to 1.0 is used to index the suitability of habitats for each of the selected species. The most suitable habitat is indexed 1.0. This habitat would provide that species needs in total or provide an integral part of its lifecycle without which it would not be able to maintain its existence. On the other hand, if a habitat provides low abundance of food, no shelter and therefore is of poor quality a score of 0.1 can be applied. Habitats not providing any support to the species at all would have a value of 0. A guide is given below taken from Standards for Developing Habitat Suitability Indices . ESM103 (U. S. Fish and Wildlife Service. 1981)
5.14 No allowance is made for seasonal variations, i.e. due to the availability of prey species at different times of year, has been made in developing the HSI. It is considered a habitat valued at 1 at a particular period but not at other times will remain at a value of 1 being necessary to support that species at that time of year when other prey may not be so readily available.
5.15 For the purposes of this assessment a HSI for greater horseshoe bats is used. The maternity and hibernation roosts of greater horseshoe bats is cited as a feature, whereas only the hibernation roosts of lesser horseshoe bats are listed. Both horseshoe bat species are active in the winter period depending on temperature (Williams 2001: in Bat Conservation Trust/BMT Cordah, 2005). In England radio-tracking of bats revealed that they foraged on average to a maximum distance of 1.2 kilometers from the hibernation site. One bat traveled to an absolute maximum distance of 2.1kilometers. The winter foraging range appears to be approximately half the area covered in the summer months. (Bat Conservation Trust/BMT Cordah, 2005) Therefore it is considered that it is unlikely that the Haybridge allocation sites are used in winter. It is also considered that any offset habitat creation designed for greater horseshoe bats would also suit lesser horseshoe bats,
25
Validation 5.16 Normally the validation of the model should be seen as a continuous refinement process and models should be reviewed from time to time and up dated. Elements such a minimum viable areas should also be reviewed and adjusted as survey increases our knowledge of a species. Garshelis (2000) concludes that the ' ...utility of the models is to guide further study or help make predications and decisions regarding complicated systems; they warrant testing but the testing should be viewed as a never-ending process of refinement, properly called bench-marking or calibration .'
Habitat Evaluation: Calculating the Biodiversity Offset 5.17 The Habitat Evaluation Process (HEP) analysis is structured around the calculation of Habitat Units (HU). The HU is defined as the product of the HSI (quality) and the total area of affected habitat (quantity). The area of habitat for a species would include all areas that can be expected to provide support for that species. (U. S. Fish and Wildlife Service, 1980)
5.18 In this case the accessibility of habitats to horseshoe bats at both Haybridge sites have been considered. All OS Mastermap polygons that are adjacent to flight lines are included at the appropriate value.
5.19 Where a habitat is valued in the HSI at 1.0, 1 hectare will provide 1 hectare of required habitat (Ritcey et al , 1998). This counts as 1 HU. Therefore, 10 hectares of a habitat valued at 0.1 would be required to make up 1 HU. There is an assumption that habitat values are related on a linear relationship and that a change from 0.8 to 0.9 is the same as a change from 0.1 to 0.2 (Treweek, 1999).
5.20 The HUs are calculated by multiplying the HSI (quality) x hectares (quantity). For example a HSI score of 0.7 will be counted as 0.7 x the area in hectares: 3 hectares will require an offset of 2.1 habitat units (hectares).
5.21 These scores are further modified depending on the distance from the roost sites. There are 4 zones or band modifiers within the home range of greater horseshoe bats are shown in Table 2. This reflects less intensive habitat use at distances away from the roost sites. For example in one study density of lesser horseshoe bat foraging was estimated to be 5.8 bats per hectare within 200 metres of the maternity roost, decreasing to 1 bat per hectare at 390 metres and 0.01 bats per hectare at 1200 metres. (Bontadina et al , 2002).
5.22 When two zones occur within one Compartment the higher value is used
26 as the modifier.
Table 2: CZ Band Modifiers (extracted from Burrows, 2012) Range (Metres) Consideration Zone Modifier 0 to 500 1 1 500 to 2420 2 0.75 2421 to 4340 3 0.5 4341 to 5750 4 0.25
Multipliers 5.23 There is wide acknowledgement that ratios should be generally well above 1:1. Thus, compensation ratios of 1:1 or below should only be considered when it is demonstrated that with such an extent, the measures will be 100% effective in reinstating structure and functionality within a short period of time (e.g. without compromising the preservation of the habitats or the populations of key species likely to be affected by the plan or project). ’ (European Communities, 2007)
5.24 Defra has set out three multipliers to be applied to biodiversity offsets to counter risk in three areas: delivery, spatial and temporal.As different habitats have different levels of difficulty in creation or restoration of there will be different risks associated with each. Defra (2012) consider that restoration is likely to be a lower risk than creation.
‘Table 3: Multipliers for different categories of delivery risk (Defra, 2012) Difficulty of recreation/restoration Multiplier Very High 10 High 3 Medium 1.5 Low 1
5.25 Spatially an offset located so that it is accessible to a species population affected has a multiplier of 1:1; this would be the case in this assessment.
5.26 In delivering offsets there may be a difference in timing between the implementation of the development and the functionality and maturity of the offset. Where a time lag occurs a multiplier will be applied to take account or the risk involved to the ‘no net biodiversity loss’ and a ‘net gain where possible’ objective. Defra (2012) have based the time period multiplier recommendation from their Environmental Liability Directive guidance and that used in the Treasury Green Book, which recommends a discount rate of 3.5%. These are set out in Table 4 below.
27 Table 4: Multipliers for different time periods using a 3.5% discount rate (Defra, 2012) Years to target condition Multiplier 5 1.2 10 1.4 15 1.7 20 2.0 25 2.4 30 2.8 32 3
Habitat Suitability Index for Greater Horseshoe Bat 5.27 The following table sets out the HSI scores for greater horseshoe bats for each habitat present on the allocations sites putting a value against each habitat derived from those used with the Somerset Biodiversity Offsetting Strategy (2012).
Table 5: Greater Horseshoe Bat HSI Habitat IHS Code HSI Score Comment
Arable CR2 0.1 Although probably not very productive in moth biomass the habitat nonetheless contributes to the overall prey biomass of the site. It is assumed that pesticides are used on some fields and that some are set aside lacking any data on management. Arable Field Margin CR6 0.2 Longer swards benefit the larvae of noctuid moths. (Ransome, 1996) Improved Grassland: GI0, GM11 0.75 A study by Duvergé and Jones (1994) Cattle grazed found that greater horseshoe bats preferred the following habitats (in descending order): pastures with cattle (either single/mixed stock), ancient semi- woodland and pastures with non-cattle stock. Woodlands and pasture close to woodland were used to a greater extent in spring and early summer while pasture was predominantly used in summer. Rides, footpaths, hedges and tree lines were used Broadleaved WB3, WF2 0.45 by greater horseshoe bats when flying in Woodland: Plantation these feeding areas. The bats were generally less than 2m away from these structures. Scrub WB2 0.4 Edges may provide commuting habitat and habitat for moth species for example where hawthorn is present
Important Hedgerows: LF111, LM1 0.4 Larger hedgerows are required for Cut hedge commuting and also foraging by greater horseshoe bats. Continuous lines of Important Hedgerows: LF111, LM2 0.6 vegetation of sufficient height and Uncut hedge thickness to provide darkness when light
28 Habitat IHS Code HSI Score Comment
Important Hedgerows: LF111, 0.75 levels are still relatively high are needed for Overgrown hedge with LM31 commuting bats. (Ransome, 1996) An standards important hedgerow is also defined by Unimportant LF11Z, 0.1 structure, i.e. 3 metres or over in height Hedgerows: Cut hedge LM1 (Limpens & Kapteyn, 1991) Open Water: Standing: AS0, AP1 0.2 Open water provides little in the way of Pond prey commonly hunted by greater horseshoe bats. Although ditches and rhynes have found to be used for commuting (Jones & Billington, 1999) it is Open Water: Standing: AS0, AC1Z 0.2 considered that ditches on these sites Drains, rhynes and would not contribute to the commuting ditches corridors already provided by hedgerow structure
Offset Assessment for Haybridge North 5.28 In order to calculate the value of the proposed allocation site each compartment or habitat area on site is assigned a number as those given in the Sunflower International Ecological Consultancy Phase1 habitat survey. These are shown in Figure 4 below.
Figure 4: Haybridge North – Compartment and Hedgerow Numbering
29 5.22 It is assumed that providing the counter-acting measures set out for street lighting given above is included that Hedgerows H5, H6 and H8 would remain and be accessible to greater horseshoe bats. This also assumes that any internal footpaths between the edge of the built development and the hedgerows would be informal and unlit.
5.23 It is considered that areas designated as recreational space would be avoided by horseshoe bats as much as built development assuming this is amenity grassland, including sports pitches, play grounds, etc. These areas are also likely to support lit cycle ways and footpaths.
5.24 The scrub habitat in Compartment 4 has been included in the offset calculations as it is unclear as to whether some of this habitat would be lost to a footpath / cycle way connection from the proposed allocation to the Leisure Centre. In addition it is likely to be a requirement that this route would be street lit, which would extend the effect.
5.25 In addition another 0.26ha of scrub would similarly be affected off site on the cycle route along the former railway to the Leisure Centre and this is included in the calculation.
5.26 Table 7 sets out the calculation of the amount of offset habitat required to compensate for the loss of habitat due to the proposed allocation. The site lies between 500 and 2420 metres from the Wookey Hole roosts .
Table 7: Haybridge North Offset Calculation Compartment Habitat IHS Hectares HSI Score HSI CZ HUs No. Type Codes Modifier Zone (ha) 1, 3 & 5 Arable CR2 8.1 0.1 1 0.75 0.6075 Arable 1, 3 & 5 CR6 0.27 0.2 1 0.75 0.0405 Margin 2 Pond AS0, AP1 0.01 0.2 1 0.75 0.0015 LF111, H1 Hedgerow 0.06 0.4 1 0.75 0.018 LM1 LF111, H2 Hedgerow 0.04 0.4 1 0.75 0.012 LM1 LF111, H3 Hedgerow 0.01 0.6 1 0.75 0.0045 LM2 LF111, H4 Hedgerow 0.02 0.6 1 0.75 0.009 LM2 LF111, H7 Hedgerow 0.03 0.4 1 0.75 0.009 LM1 LF111, H17 Hedgerow 0.05 0.4 1 0.75 0.015 LM1 4 Scrub WB2 0.17 0.4 1 0.75 0.051 Off site Scrub WB2 0.26 0.4 1 0.75 0.078 Total HU Required 0.846
5.27 The amount of offset habitat creation or restoration required to develop the
30 site is 0.846ha before multipliers are applied. This habitat must be accessible to greater horseshoe bats, i.e. not severed by roads or the effects of street lighting, and can be located on or off site.
5.28 The habitat creation for greater horseshoe bats on site would be the planting of native species hedgerows, especially those which encourage moth species, interspersed with areas of long grassland. Grassland should be managed with longer swards to benefit the larvae of noctuid moths (Ransome, 1996). Existing hedgerows could be reinforced and new hedgerow planted along the backs of housing or by further dividing fields.
5.29 It is considered that only the multiplier for delivery risk and difficulty need be applied as the offset habitat would be connected to existing greater horseshoe bat use of the local landscape.
5.30 Using Defra’s ‘Risk Factors for Different Habitats’ hedgerow are of low difficulty to restore or create, whilst meadows are considered to be of moderate difficulty to recreate and low difficulty to restore. Difficulty risk is therefore considered to be slightly more than low and a multiplier of 1.2 has been selected. (See Table 3)
5.31 The habitats will take less than five years to establish therefore the Delivery risk is considered to be 1.2. (See Table 4)
5.32 Following the application of Fraction Multipliers a minimum of 1.22ha of habitat creation would be need to be specified in policy to enable the allocation site to be included in the Local Plan. This is likely to be within the area to the west of the site as a new school will reduce availability and possibly accessibility of on site offset habitat creation following the requirement by Somerset County Council for a new school (email: John Meeker, 14/11/2012)
Offset Assessment for Haybridge South 5.33 In order to calculate the value of the proposed allocation site each compartment area on site is assigned a number and hedgerows are numbered as those given in them Aspect Ecology Phase1 habitat survey. These are shown in Figure 5 below.
5.34 Both housing areas and any associated recreational open space are considered hostile to greater horseshoe bats.
5.35 Access to the site would be via Wheeler Grove and the road would need to cross the area designated as recreational open space. An additional access road would be required Glencott Road, north of Elfrida Terrace, to Compartment 1. This road does not need to be street lit. (pers. comm.
31 John Gallimore, Highways Development Control, Somerset County Council) It is assumed that the access road would need to be lined with shrubs and trees either side to provide connectivity to horseshoe bats. It is also assumed that the total width of highway would not be more than 10 metres. These conditions would need to be included in the Policy in the Local Plan to ensure access is maintained to habitat to the south.
5.36 It is assumed that providing the counter-acting measures set out for street lighting given above is included that Hedgerows H20, H2, H18, H4, H5, H10 and H9 would remain and be accessible to greater horseshoe bats. This also assumes that any internal footpaths between the edge of the built development and the hedgerows would be informal and unlit.
Figure 5: Haybridge South – Compartment and Hedgerow Numbering
5.37 Table 8 sets out the calculation of the amount of offset habitat required to compensate for the loss of habitat due to the proposed allocation. The site lies between 500 and 2420 metres from the Wookey Hole roosts .
32
Table 8: Haybridge South Offset Calculation Compartment IHS HSI CZ Habitat Type Hectares HSI Score HUs (ha) No. Codes Modifier Zone 1 Arable CR2 2.12 0.1 1 0.75 0.159
Arable 1 CR6 0.74 0.2 1 0.75 0.111 Margin 4 (for access road) Arable CR2 0.09 0.1 1 0.75 0.00675
GI0, Improved 2 & 3 GM111 3.98 0.75 1 0.75 2.23875 Grassland
LF11Z, H1 Hedgerow LM1 0.03 0.1 1 0.75 0.00225
LF11Z, H7 Hedgerow 0.01 0.1 1 0.75 0.00075 LM2 LF11Z, H8 Hedgerow 0.02 0.1 1 0.75 0.0015 LM3 LF111, H3 Hedgerow 0.02 0.75 1 0.75 0.01125 LM31 LF111, H6 Hedgerow 0.03 0.75 1 0.75 0.01688 LM31 AS0, WC1 & WC2 Watercourse 0.01 0.2 1 0.75 0.0015 AC1Z
Total HU 2.54963 Required
5.38 The amount of offset habitat creation or restoration required to develop the site is 2.55ha before multipliers are applied. This habitat must be accessible to greater horseshoe bats, i.e. not severed by roads or the effects of street lighting, and can be located on or off site.
5.39 The habitat creation for greater horseshoe bats on site would be the planting of native species hedgerows, especially those which encourage moth species, interspersed with areas of long grassland. Grassland should be managed with longer swards to benefit the larvae of noctuid moths (Ransome, 1996). Existing hedgerows could be reinforced and new hedgerow planted along the backs of housing or by further dividing fields.
5.40 It is considered that only the multiplier for delivery risk and difficulty need be applied as the offset habitat would be connected to existing greater horseshoe bat use of the local landscape.
5.41 Using Defra’s ‘Risk Factors for Different Habitats’ hedgerow are of low difficulty to restore or create, whilst meadows are considered to be of
33 moderate difficulty to recreate and low difficulty to restore. Difficulty risk is therefore considered to be slightly more than low and a multiplier of 1.2 has been selected. (See Table 3)
5.42 The habitats are likely to take less than five years to establish therefore the Delivery risk is considered to be 1.2. (See Table 4)
5.43 In this case, assuming that the habitat will be offset to the west of the development areas an allowance must be made for the existing habitat in the calculations. Arable land is valued at an HSI of 0.1. Following application the multipliers the total is 3.69ha. This will increase to 4.1ha if the offset is applied to an existing land use of arable habitat. Other land uses would result in a higher offset being required as the existing land use is likely to be of greater value to horseshoe bats. The offset should not be implemented within 30 metres of the A371 due to potential noise issues affecting use by greater horseshoe bats. There would be approximately 10ha of land within the red line available. However, it should be noted that use of Compartment 4 is essential to unable access to continue.
5.44 A minimum of 4.1ha of habitat creation would need to be specified in policy to enable the allocation site to be included in the Local Plan. This needs to include habitat creation and enhancement in Compartment 4.
5.45 If compartment 8 were to be allocated for development the amount of Offset required would increase as calculated in Table 9. It is considered that in addition to Compartment 8 Hedgerows H9 and H13 would also become unavailable to horseshoe bats. It is considered that Hedgerow 12 would not be used by horseshoe bats due to the proximity of traffic noise from the A371. A further 0.08ha is taken from the area of Compartment 8 also to allow for this effect.
Table 9: Haybridge South Offset Calculation (including Compartment 8) Compartment IHS HSI CZ Habitat Type Hectares HSI Score HUs (ha) No. Codes Modifier Zone 1 Arable CR2 2.12 0.1 1 0.75 0.159
Arable 1 CR6 0.74 0.2 1 0.75 0.111 Margin 4 (for access road) Arable CR2 0.09 0.1 1 0.75 0.00675
GI0, Improved 2 & 3 GM111 3.98 0.75 1 0.75 2.23875 Grassland
LF11Z, H1 Hedgerow LM1 0.03 0.1 1 0.75 0.00225
LF11Z, H7 Hedgerow 0.01 0.1 1 0.75 0.00075 LM2
34 Compartment IHS HSI CZ Habitat Type Hectares HSI Score HUs (ha) No. Codes Modifier Zone H8 LF11Z, Hedgerow 0.02 0.1 1 0.75 0.0015 LM3
LF111, H3 Hedgerow 0.02 0.75 1 0.75 0.01125 LM31 LF111, H6 Hedgerow 0.03 0.75 1 0.75 0.01688 LM31 AS0, WC1 & WC2 Watercourse 0.01 0.2 1 0.75 0.0015 AC1Z Improved GI0, 8 Grassland 4.02 0.75 1 0.75 2.26125 GM111
LF111, H9 Hedgerow 0.05 0.75 1 0.75 0.02813 LM31 LF11Z, H13 Hedgerow 0.04 0.1 1 0.75 0.003 LM2
Total HU 4.842 Required
5.46 The amount of offset habitat creation or restoration required to develop the site is 4.84ha before multipliers are applied. Again this habitat must be accessible to greater horseshoe bats, i.e. not severed by roads or the effects of street lighting, and can be located on or off site.
5.47 Using Defra’s ‘Risk Factors for Different Habitats’ hedgerow are of low difficulty to restore or create, whilst meadows are considered to be of moderate difficulty to recreate and low difficulty to restore. Difficulty risk is therefore considered to be slightly more than low and a multiplier of 1.2 has been selected. (See Table 3) The habitats are likely to take less than five years to establish therefore the Delivery risk is considered to be 1.2. (See Table 4) Following application the multipliers the total is 6.97ha.
5.48 In this case, assuming that the habitat will be offset to the west and north of the development areas an allowance must be made for the existing habitat in the calculations. Arable land is valued at an HSI of 0.1. This will increase to 7.7ha if the offset is applied to an existing land use of arable habitat. Other land uses would result in a higher offset being required as the existing land use is likely to be of greater value to horseshoe bats.
5.49 There would be approximately 5.9ha of land within the red line available in Compartments 4, 5, 6 and 7. Access to Compartments 5, 6 and 7 requires that Compartment 4 not be developed but used for offset habitat enhancement and creation. However, approximately 1.8ha of offset habitat creation would be required outside of the red line boundary.
5.50 A location for the off site offset habitat creation would need to be included
35 in the Local Plan if the whole of Compartment 8 is developed.
Recommended Policy Amendment 5.51 Core Policy 10, Wells City Strategy needs to be amended to take into account the findings of the assessment above. The following wording is recommended:
A masterplan for the site will be prepared and adopted as a Supplementary Planning Document (SPD) to guide the allocation and phased release of land to maintain housing supply. Following the findings of a Habitats Regulations Assessment of the allocated sites to the west (in the area between the A371 and Wookey Hole Road) of Wells masterplans are likely to be required to provide a minimum of 1.22 hectares on the site south of Wookey Hole Road and 4.1 hectares on the site north of the A371 that is accessible to horseshoe bats to offset the loss of habitat supporting the North Somerset and Mendip Bat SAC. Masterplans will also need to take into account the effects of street and other lighting on bats and their prey.
An access road is required for the site north of the A371 (Haybrdge South). This is required to be unlit and lined with hedgerow and trees to enable continued access to the south by bats.
5.52 It is also recommended that any habitat offset requirement be contained within the existing red line boundaries and that the built development and its associated infrastructure are limited to an area that enables this requirement to be met.
6. Conclusion
6. 1 It is the consideration of Mendip District Council that providing the recommended counter acting measures are included in Core Policy 10: Wells Strategy there is unlikely to be significant effect on the greater horseshoe bat feature of the North Somerset and Mendip Bat SAC.
36 References
Alford, D. V. 2011. Plant Pests . London: HarperCollins Publishers.
Barataud, M., Faggio, G., Pinasseau, E. & Roué, S. G. 2000. Protection et restauration des habitatas de chasse du Petit rhinolophe ( Rhinolophus hipposideros ) Année 2000 . Paris: Ministère de l’Environnement – Direction de la Nature et des Paysages.
Bat Conservation Trust. 2007. Bat Surveys - Good Practice Guidelines . London: Bat Conservation Trust.
Bat Conservation Trust/Institute of Lighting Engineers. 2008. Bats and Lighting in the UK: Version 2 .
Bat Conservation Trust/ BMT Cordah Limited. 2005. A Review and Synthesis of Published Information and Practical Experience on Bat Conservation within a Fragmented Landscape . The Three Welsh National Parks, Pembrokeshire County Council & Countryside Commission for Wales.
Billington, G. 2000. Radio tracking study of greater horseshoe bats at Mells, Near Frome, Somerset . Peterborough: English Nature
Bontadina, F., Schofield, H. & Naef-Daenzer, B. 2002. Radio-tracking reveals that lesser horseshoe bats (Rhinolophus hipposideros) forage in woodland. J. Zool. Lond. (2002) 258, 281-290 .
Bontadina, F., Gloor, S., Hotz, T. Bech, A., Lutz, M. & Mühlrthaler, E. 2002. Foraging range use by a colony of greater horseshoe bats Rhinolophus ferrumequinum in the Swiss Alps: implications for landscape planning: in Bontadina, F. 2002. Conservation ecology in the horseshoe bats Rhinolophus ferrumequinum and Rhinolophus hipposideros . Bern: University of Bern
Boye, Dr. P. & Dietz, M. 2005. Development of good practice guidelines for woodland management for bats: English Nature Research Reports Number 661. Peterborough: English Nature.
Brinkmann, R., Bach L, Biedermann, M., Dietz, M., Dense, C., Fiedler, W., Fuhrmann, M., Kiefer, A., Limpens, H., Niermann, I., Schorcht, W., Rahmel, U., Reiter, G., Simon, M., Steck, C. & Zahn, A. 2003. Crossing Points for Bats – limiting damage in habitat fragmentation by transport projects. Position Paper of the Wildlife Crossing Points Working Party. www.buero-brinkmann.de
Burrows, L. 2012. A Biodiversity Offsetting Methodology . Taunton: Planning 4 Biodiversity,
37 Council of Europe. 2000. Action Plan for the Conservation of the Greater Horseshoe Bat in Europe (Rhinolophus ferrumequinum) Strasbourg: Council of Europe
Cresswell Associates. 2004. Bats in the Landscape Project . The National Trust, Sherborne Park Estate.
Defra, 2009. Scoping study for the design and use of biodiversity offsets in an English Context, Final Report to Defra (Contract NE 0801)
Defra, 2012. Biodiversity Offsetting Pilots Technical Paper: the metric for the biodiversity offsetting pilot in England, March 2012 . London: Department for Environment, Food and Rural Affairs. http://www.defra.gov.uk/publications/files/pb13745-bio-technical-paper.pdf
Dietz, C., von Helversen, O. & Nill, D. 2009. Bats of Britain, Europe and Northwest Africa . London: A. & C. Black Publishers Ltd.
Duverg ė, P. L. & Jones, G. 1994. Greater Horseshoe Bats - Activity, foraging behaviour and habitat use: in British Wildlife Vol. 6 No 2
Emery, M. 2008. Effects of Street Lighting on Bats . Urbis Lighting Ltd.
English Nature. 1997. Habitats Regulations Guidance Notes 1: The Appropriate Assessment (Regulation 48) The Conservation (Natural Habitats &c) Regulations, 1994 . Peterborough: English Nature.
English Nature. 1999. Habitats Regulations Guidance Notes 3: The Determination of Likely Significant Effect under The Conservation (Natural Habitats &c) Regulations 1994. Peterborough: English Nature.
English Nature. 2001. Habitats Regulations Guidance Notes 4: Alone of In Combination . Peterborough: English Nature.
Entwhistle, A. C., Harris, S., Hutson, A. M., Racey, P. A., Walsh, A., Gibson S. D., Hepburn, I. & Johnston, J. 2001. Habitat management for bats: A guide for land managers, landowners and their advisors. Peterborough: Joint Nature Conservation Committee.
European Communities. 2000. Managing Natura 2000 Sites: The provisions of the Article 6 of the ‘Habitats’ Directive 92/43/EEC. Brussels: Office for Official Publications of the European Communities.
Jones, Dr. G. & Billington, G. 1999. Radio tracking study of greater horseshoe bats at Cheddar, North Somerset. Taunton: English Nature.
38 Knight Ecology. 2008. Hestercombe House, Taunton, Somerset: Lesser Horseshoe Bat Diet Analysis. Clutton: Knight Ecology
Knight, T. 2007. The use of landscape features and habitats by the Lesser Horseshoe bat. Ph.D thesis. University of Bristol. (presentation at Horseshoe Bat Conference, Shipham, 2007 )
Knight, T. & Jones, G. 2009. Importance of night roosts for bat conservation: roosting behaviour of the lesser horseshoe bat Rhinolophus hipposideros . Endang. Spec. Res. doi: 10.3354/esr00194
Limpens, H. J. G. A. & Kapteyn, K. 1991. Bats, their behaviour, and linear landscape elements: in Myotis 29: 63-71 .
Limpens, H. J. G. A., Twisk, P. & Veenbass, G. 2005. Bats and road construction . Deflt: Rijkswaterstaat, Dienst Weg- en Waterbouwkunde/ Arnhem: Vereniging voor Zoogdierkunde en Zoogdierbescherming.
Outen, A. R. 2002. The ecological effects of road lighting: in Sherwood, B., Cutler D. & Burton J. (eds.) 2002. Wildlife and Roads: The Ecological Impact. London: Imperial College Press.
Mitchell-Jones, A. J. 2004. Bat mitigation guidelines . Peterborough: English Nature.
Motte, G. & Libois, R. 2002. Conservation of the lesser horseshoe bat (Rhinolophus hipposideros Bechstein, 1800) (Mammalia: Chiroptera) in Belgium. A case study in feeding requirements. Belg. J. Zool., 132 (1): 47-52.
Natural England. 2010. Working design principles for the creation of vegetated corridors for horseshoe bats within new developments (Second version). Unpublished paper. Natural England West of England Team.
Ransome, R. D. 1996. The management of feeding areas for greater horseshoe bats : English Nature Research Reports Number 174. Peterborough: English Nature.
Ransome, R. D. 1997. The management for greater horseshoe bat feeding areas to enhance population levels : English Nature Research Reports Number 241. Peterborough: English Nature.
Ransome, R. D. 2002. Winter feeding studies on greater horseshoe bats: English Nature Research Reports Number 449. Peterborough: English Nature
Ransome, R. D. 2008. Greater horseshoe bat Rhinolphus ferrumequinum : in Harris, S. & Yalden, D. W. (eds.) 2008. Mammals of the British Isles: Handbook,
39 4th Edition . Southampton: The Mammal Society.
Rossiter, S. J., Jones, G., Ransome, R. D. & Barratt, E. M. 2002 Relatedness structure and kin-based foraging in the greater horseshoe bat ( Rhinolophus ferrumequinum ): in Behav. Ecol. Sociobiol. (2002) 51: 510-518
Schaub, A., Ostwald, J. & Siemers, B. M. 2008. Foraging bats avoid noise. J. Exp. Biol. 211, 3174 – 3180.
Schofield, H. W. 2008. The Lesser Horseshoe Bat Conservation Handbook. Ledbury: The Vincent Wildlife Trust.
Schofield, H., Messenger, J., Birks, J. & Jermyn, D. 2003. Foraging and Roosting Behaviour of Lesser Horseshoe Bats at Ciliau, Radnor . Ledbury: The Vincent Wildlife Trust
Stone, E. 2009. The impact of street lighting on lesser horseshoe bats: Unpublished PhD, University of Bristol. Presented at the South West Bat Conservation Trust Conference, 25 April, 2009 .
Stone, E. L., Jones, G. & Harris, S. 2009. Street Lighting Disturbs Commuting Bats. Current Biology 19, 1123–1127, July 14, 2009
Treweek, J. 1999. Ecological Impact Assessment . Oxford: Blackwell Science Ltd.
U. S. Fish and Wildlife Service. 1980. Habitat Evaluation Procedures ESM102 . Washington, D. C.: Department of the Interior.
U. S. Fish and Wildlife Service. 1981. Standards for Developing Habitat Suitability Indices . ESM103 . Washington, D. C.: Department of the Interior
Vaughn, N., Jones, G. & Harris, S. 1997. Habitat use by bats (Chiroptera) assessed by means of broad-band acoustic method: in Journal of Applied Ecology 34, 716-730 .
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