public inquiry question - bailey.persona-pi.combailey.persona-pi.com/public-inquiries/m4-newport/e -...

M4 Corridor around Newport

PUBLIC INQUIRY QUESTION

REFERENCE NO. : PIQ /083

RAISED BY: The Inspectors DATE: 20/03/17

RESPONDED BY: Matthew Jones DATE: 03/05/17

SUBJECT: Bats Proof of Evidence Clarification

The attached document provides responses to questions of elucidation raised by Mr Wadrup in

correspondence dated 20 February 2017.

Welsh Government M4 Corridor around NewportBats POE Clarification

May 2017

Page 1

Bats Proof of Evidence Clarification Richard Green BSc (Hons) CEnv MCIEEM

Contents

1. Introduction ....................................................................................... 2

2. Clarifications ..................................................................................... 2


May 2017

Page 2

1. Introduction

1.1 This document provides a response to points of elucidation raised by Mr

Wadrup in correspondence dated 20 February 2017.

2. Clarifications

2.1. Evidence paras 7.8.13-16 Question: It would be helpful to have a map

showing where the bats are identified in numbers now (Magor lesser

horseshoe and Berry Hill common pippestrelle) and where, now, they fly

or commute to eg Wye Valley and Forest of Dean Sites , so the “barrier”

of the proposed road can be put into geographical context relative to

current hazards and alternatives to the published line.

2.2. Evidence paras 7.8.13-16 Response: Lesser horseshoe bats around

Magor. The figures below, taken from ES documents and edited for

clarity, seek to answer question 1. The following text explains the current

knowledge of bat movement in these areas. Figure 1 of the Statement to

Inform Appropriate Assessment (SIAA) show the location of the Wye

Valley and Forest of Dean SAC constituent sites in relation to the

Scheme and all lesser horseshoe bat survey records. Figure 3e of the

Statement to Inform Appropriate Assessment shows where the majority

of lesser horseshoe bat activity was recorded around Magor. It must be

noted that the number of bat passes does not necessarily equate with

number of bats but is simply a measure of activity.

2.3. We do not know if, how many, and along what route lesser horseshoe

bats from the Wye Valley and Forest of Dean Bat Sites SAC travel to the

Scheme area. We do know that lesser horseshoe bats fly under the

existing M4 using Mill Reen Underpass.

2.4. No lesser horseshoe bats were recorded during bat activity transects

during 2014. Static bat detector surveys in 2014/2015 were located

along the Scheme route and it is extremely likely that lesser horseshoe

bats also forage in the area away from the Scheme. The existing A4810,


May 2017

Page 3

which is lit from the Magor interchange/Junction 23A to the South Wales

Mainline Railway and lies adjacent to the proposed line of the Scheme in

this area, provides a potential barrier to bats in this area. If crossing the

existing A4810 presently, bats are likely to be using the existing South

Wales Mainline Railway underpass on the A4810.

2.5. There are no known lesser horseshoe bat maternity roosts around

Magor. The only known lesser horseshoe bat roost is a ‘low-use’ day or

night roost that was found in February 2017, when internal access to the

coach house at Woodland House, Magor was arranged (a report will be

provided for the listed building inquiry in due course). Approximately 200

mixed age bat droppings were present in the building. Whilst this might

sound like a lot of droppings, it is indicative of occasional use over

several years by one or a small number of bats. Further survey on this

building is planned in summer 2017 to determine levels of use.


May 2017

Page 4


May 2017

Page 5


May 2017

Page 6


May 2017

Page 7


May 2017

Page 8

2.6. Evidence paras 7.8.13-16 Response: Common pipistrelle bats

around Berryhill Farm. Figure 2e of ES Appendix 10.23 (on page 12 of

this document) shows relative levels of bat activity around Berryhill Farm

from static bat detectors in 2014 and 2015. Most this activity is from

pipistrelle bats. Pipistrelle bat activity has been summarised on the

Figure for this document.

2.7. The following italicised text is an extract from ES Appendix 10.7 at

paragraph 3.3.1, summarising bat survey findings for Transect 1 (2014;

refer to figures on page 13).

2.8. “Common and soprano pipistrelle were the most frequently recorded

species on Transect 1, although Myotis bats were also regularly

recorded on the Transect. Occasional passes of noctule (Nyctalus

noctula), Leisler’s bat (Nyctalus leislerii) and Nathusius’ pipistrelle

(Pipistrellus nathusii) were also recorded. Bats were recorded on all

parts of the transect with the main areas of highest bat activity around

Berry Hill Farm and the woodlands to the south of the farm and in the

fields to the west. Relatively high levels of activity were also recorded

along the A48 corridor in May and August although in other months the

levels were lower. Given the proximity of a known roost at Berry Hill

Farm the relatively high levels of pipistrelle bats is to be expected.”

2.9. It is not possible to know exactly where pipistrelle bats from Berry Hill

Farm and The Conifers maternity roosts fly to and along which routes.

However, it is reasonable to assume that bats will fan out from the roost

along hedgerows/tree-lined field boundaries and woodland, with bat

numbers diverging as distance from the roosts increases.

2.10. The main corridors and foraging areas are considered likely to be the

woodland and tree-lines to the south and east of Berryhill Farm, along

with the tree-lined A48 to the west. Similar behaviour is expected from

brown long-eared bats breeding at Berryhill Farm, although this species

is more associated with woodland and trees and tends to range over


May 2017

Page 9

less distance from a maternity roost (most foraging activity observed

within 2 km of maternity roosts).

2.11. No bats were observed flying over the existing M4 using Pound Hill

Bridge during three surveys in September 2015. However, there is an

underpass under the existing M4 at Grid Reference ST 27233 84620

that has not been surveyed (refer to aerial photograph and Google

Street View below). The height marker on the underpass reads 14-0’, so

it is estimated that the underpass is approx. 5m w x 4.2 h. This could be

used by bats, including pipistrelles and brown long-eared bats from

Berryhill Farm to access woodland foraging habitat to the north of the

existing M4. Bat survey at the culvert could be undertaken this season

(from April 2017) to confirm bat use.

Location of underpass (Point B) under existing M4 in relation to Berryhill Farm


May 2017

Page 10

View of underpass from the south


May 2017

Page 11


May 2017

Page 12


May 2017

Page 13

2.12. Para 7.8.12 Question: What evidence substantiates your claim of “over

evaluation”?

2.13. Para 7.8.12 Response: As stated in 3.4.2 & 3.4.3 of my proof, Wray et al. state

that their approach should be used as a framework rather than a rulebook.

Their approach was the first attempt in the UK to assign values for bat in EcIA,

and although not strictly a recognised standard, it has been adopted by

ecologists, as published in the CIEEM journal ‘In Practice’ (December 2010), in

the absence of any alternative.

2.14. The method of evaluation relies heavily on knowing the approximate number of

bats (individuals, small number or large number) using a commuting route or

foraging area. Unfortunately, without direct observation, it is impossible to

determine the number of bats foraging in an area. Even with direct observation,

if an individual bat flies out of sight and then returns, it is not possible to be

certain if this is one or two bats. It is also impossible to observe bats effectively

after dusk and before dawn, when it is too dark to see them. Static bat

detectors are therefore a suitable alternative for measuring bat activity.

However, activity level is all that can be deduced from their recordings. They

cannot count individual bats. Where high levels of bat activity are recorded, it is

impossible to say whether this is due to a high number of bats flying past or one

bat foraging for a prolonged period in the same area, repeatedly flying past the

bat detector, which records each pass.

2.15. Pipistrelle bats have relatively loud calls and are readily recorded by bat

detectors. They also have a habit of foraging in the same location for prolonged

periods, particularly along the edge of tree canopies and tall hedges, and

around street lights, as they feed on the insects attracted to them. In my

experience of undertaking an extensive amount of bat activity survey, other

species that forage for prolonged periods in an area include Myotis and

serotine bats and to a lesser extent, barbastelle, noctule and Leisler’s bats,

particularly when foraging along hedgerows. In my experience, long-eared and

horseshoe bats tend to be more wandering species, not repeatedly flying up

and down the same hedgerow for extensive periods. Some bat species, e.g.,

long-eared, have very quiet calls and therefore may be under-recorded.


May 2017

Page 14

2.16. Therefore, it is very difficult to determine even an approximate number of bats

commuting or foraging, e.g., along a hedgerow/reen. The following activity

levels were used to assign ‘number of bats’ in the valuation for bats in the ES.

Over, on average, 100 passes per night = large number; on average, between

10 and 100 passes per night = small number; and on average, less than 10

passes per night = individuals. This is a reasonable conversion but as there is

no way of confirming numbers, the valuation could be grossly affected by an

over (or under) estimation. It would not take long for one bat to generate 100

bat passes when foraging up and down the same hedge repeatedly. One pass

does not even equate to one actual pass of the detector, as it is possible for the

detector to record two or more passes as the bat approaches and passes the

detector.

2.17. Therefore, the assessment based on bat activity alone could be misleading and

the landscape is an important consideration in valuing the area for bats. As

discussed in paragraph 3.4.3 of my proof of evidence [WG 1.20.1] the fields

between the hedges and reens over the levels are unlikely to provide valuable

bat foraging habitats. It is acknowledged that the hedges/tree lines and reens

do provide a valuable habitat network but when one considers the results of the

walked transect surveys, the more open and exposed areas over the levels

tended to have less bat activity. The highest levels of bat activity tend to be

found where there is more tree cover.

2.18. As the valuation for bats uses a geographical reference, I looked at the area

around Newport and South Wales using aerial photography on Google Earth.

For the most part, excluding cities and large towns, South Wales contains a

relatively high density of woodland compared to the rest of the UK, and also

comprises of a patchwork of many small fields bounded by a network of hedges

and tree lines. There are also many wooded valleys and river systems. These

habitats provide favourable habitats for bats because of a high insect

abundance and diversity and, in particular, more shelter from the wind than

would be present on the levels, meaning that prey availability is likely to be

greater on average, as open habitats provide little available insect prey in windy

conditions. Therefore, if one considers the valuation of bat foraging habitat


May 2017

Page 15

based on habitats available in the region, rather than just basing it on numbers

of bat calls recorded on bat detectors, the Levels are, in my opinion, likely to be

less valuable than other areas in South Wales. Coupled with this, the areas at

each end of the Scheme are currently subject to ‘disturbance’ and habitat

degradation from the existing M4 and A-roads, industrial areas and housing

development, whilst Newport docks provides low value bat habitat.

2.19. I suspect that if similar bat survey was undertaken across the whole of Wales

(excluding urban areas and coastal habitats), the whole of Wales would be

valued (using the Wray et al. method) as of at least regional value. If the

purpose of having a geographical frame of reference for valuation is so that one

can identify the most important areas for bats within a larger area, such as the

‘region’, my suggestion that the Scheme corridor may be of county value seeks

to compare the area with the rest of the ‘region’.

2.20. I have already raised in my proof of evidence [para. 3.4.3 of WG 1.20.1] how

the presence of one greater horseshoe bat over all of the surveys undertaken

assigns a level of regional value for this species. Whilst rare, individual greater

horseshoe bats are wide ranging. For example, an individual bat ringed in

Gloucester was subsequently found in North Wales. Therefore, the greater

horseshoe bat recorded could simply have been ‘passing through’ or exploring

the area, rather than regularly foraging in the area.

2.21. In consideration of barbastelle bats, another species considered in the ‘rarest’

category, whilst rare, this species is found across Wales and southern and

central England and it is not unusual to record this species when undertaking

such extensive bat survey as has been undertaken for this Scheme. Whilst

there are records of barbastelle, particularly at the eastern end of the Scheme,

the activity levels recorded are low (0.03 – 0.4 passes per night on average)

and ignoring the method of assessment proposed by Wray et al., it is hard to

see why such low levels of activity would justify the area being of regional value

for this species alone. The same applies to Nathusius’ pipistrelle.

2.22. Other species listed as ‘rarest’ in Wales include whiskered bat. This is a Myotis

species (Myotis mystacinus). Myotis bat species are very difficult to differentiate


May 2017

Page 16

by bat detector, as there is considerable overlap in call structure. For this

reason, the assessment has not differentiated between Myotis species and this

species group has been collectively considered as within the rarest category.

Whiskered bats are distributed across Wales and England and into Scotland

and it is extremely unusual not to record Myotis bat species when undertaking a

bat survey such as this anywhere in Wales. The same is true of noctule bat.

2.23. Table 1 from Wray et al. shows how bat species are categorised, according to

distribution and rarity. This is included below, along with distribution maps of

mentioned species.

2.24. Despite my suggestion that the Scheme corridor may be of county value for

bats, I acknowledge that up to 14 species have been recorded in the area,

including rare species, such as both horseshoes and barbastelle bat, and do

not disagree with the precautionary approach of valuing the Scheme corridor as

of regional value for bats but simply raise the issues of determining value using

the Wray et al. model to demonstrate that a precautionary approach has been

taken to the valuation and impact assessment.


May 2017

Page 17


May 2017

Page 18

Barbastelle bat distribution – taken from https://data.nbn.org.uk

Nathusius’ pipistrelle distribution – taken from http://www.nathusius.org.uk


May 2017

Page 19

Whiskered bat distribution – taken from https://data.nbn.org.uk

Noctule bat distribution – taken from https://data.nbn.org.uk

public inquiry question - bailey.persona-pi.combailey.persona-pi.com/public-inquiries/m4-newport/e -...

Documents