Bat Surveys of Hurn Forest Dorset - · PDF fileBoth surveyors used a Petterson D240x time expansion detector and Edirol R09 ... These results are shown on Maps 3a & ... 3.3.1 28 June

___________________________________________________________________________________

Colleen Hope (nee Mainstone), MCIEEM Ecological Consultancy Services Ltd (ECS)

[email protected] www.econserve.co.uk tel 01794 524232 (m) 07719 170200 copyright ECS

1

Bat Surveys of Hurn Forest Dorset

For

Hurn Parish Council

Report Author

Colleen Hope, BSc, MCIEEM

Surveyors Colleen Hope & Dr Paul Hope BSc (Hons), MCIEEM

January 2014 (final report)

___________________________________________________________________________________



2


Contents

Executive Summary 1

1.0 Site Overview & Background 2

2.0 Survey Methodology 4

3.0 Survey Results 8

4.0 Evaluation 12

5.0 Recommendations 19

6.0 Conclusions 22

7.0 References 23

Appendices

Appendix 1 Surveyor Experience

Appendix 2 Legislation & Policy

Appendix 3 Status & Distribution of Species Encountered

Bat Surveys of Hurn Forest, Dorset January 2014 (final report)

___________________________________________________________________________________



1


Executive Summary

Hurn Forest lies to the northeast of Bournemouth in Dorset, just west of the New

Forest National Park. Hurn Parish Council (HPC) manages a 370ha area of

predominantly coniferous woodland and heathland. HPC have appointed various

ecological specialists to conduct a Biodiversity Audit of the site.

Ecological Consultancy Services Ltd (ECS) was appointed by HPC to undertake

bat surveys of Hurn Forest. ECS conducted three capture surveys and two

transect routes over a total of four evenings between May-September 2013. A

total of seven bat species were confirmed to be present including a single male of

the rare species of Bechstein’s bat Myotis bechsteinii.

This report presents the methodology and results of these surveys. An overview

is given of the value of the habitats present within the site for bats together with

some observations on how future management could improve habitats for

foraging and roosting.


___________________________________________________________________________________



2

1.0 Site Description, Background & Overview of Proposed Works

1.1 Site Description

Hurn Forest encompasses an area of 370 ha comprised mainly of coniferous

plantation and heathland. The site is long and relatively narrow (approximately 5

x 13km). It is in proximity to residential areas and wider tracts of Forestry

Commission owned woodland and heathland. A wide gravel track runs

north/south through the site. There are two car parks (one at the north and one at

the south end) and the site is in regular use by dog walkers and cyclists. There is

a holiday park adjacent to part of the north west of the site. Bournemouth

International Airport is situated within 0.5km to the west.

The Moors River Site of Special Scientific Interest (SSSI) runs along much of the

western perimeter. Small streams associated with this watercourse flow across

the site towards its northern end. Part of Hurn Common SSSI is also within and

adjacent to the site. The Avon Valley Special Protection Area (SPA), Ramsar site

and SSSI is within 1.5km to the east of the site and the New Forest National Park

within 2-3km. Dorset Heaths Special Protection Area (SPA), Special Area of

Conservation (SAC) and Ramsar site are situated approximately 5km to the west.

The location of the Hurn Forest is shown on Map 1.

1.2 Background

Ecological Consultancy Services Ltd (ECS) was appointed by HPC in spring 2013

to undertake bat surveys of the site. HPC (with funding from other partners1)

have appointed a number of specialist ecologists to survey species and habitats

such as birds, reptiles, invertebrates and flora in order to feed into a Biodiversity

Audit of the site. SW Environmental is managing the ecology team and reporting

back to the parish council. The data will be used to inform future management

with particular respect to the woodland and heathland elements of the site.

1 Bournemouth Airport Community Fund, Lottery Awards for All & The Forestry Commission


___________________________________________________________________________________



3

Map 1 To Show Site Location

Ordnance Survey © Crown copyright (2007) All rights reserved. Licence number 100050545


___________________________________________________________________________________



4

2.0 Survey Methodology

2.1 Survey & Reporting Standards

Surveys & assessments were undertaken with reference to Bat Conservation

Trust2 (BCT) and Natural England survey and mitigation guidelines3 and conform

to the Chartered Institute of Ecology & Environmental Management (CIEEM)

assessment and reporting standards4. Information on surveyor background and

experience is provided in Appendix 1. Appendix 2 provides details of legislation

and policy relating to bats.

2.2 Desktop Research

A data search of bat records from within 2km of the site was commissioned from

Dorset Environmental Records Centre (DERC) by SW Environmental in spring

2013.

2.3 Visual Assessment of the Site

The site was visited on 6 April 2013 by Colleen Hope of ECS. The majority of

tracks and paths were walked noting key changes in habitats from coniferous to

deciduous woodland, healthland and pasture fields/riparian habitats. The site visit

and Forestry Commission Stock Maps were used to design two transect routes

for subsequent detector surveys. These aimed to encompass as much of each

habitat type as possible including potential foraging areas and commuting routes

whilst gaining coverage across most of the site. Each transect route was

designed to take 90-120 minutes.

Time did not permit a detailed assessment of trees for potential roost sites.

2.4 Evening Transect Surveys

Two experienced ECS surveyors5 walked two transect routes on 28 June 2013.

These are referred to as the north and south transects and are identified on Map

2 . Surveyors waited at the start of the transect route from sunset for 20 minutes

before commencing the walk. Each survey continued for 2 hours.

Both surveyors used a Petterson D240x time expansion detector and Edirol R09

recorder. Any time expansion calls needing subsequent analysis were assessed

2 Bat Surveys, Good Practice Guidelines, BCT (2012)

3 Bat Workers Manual (2004), Bat Mitigation Guidelines, (2004) both published by Natural England (formerly English

Nature)

4 IEEM Guidelines for Ecological Impact Assessment in the United Kingdom (June 2006).

5 Colleen Hope & Paul Hope. Colleen was accompanied by Simon Weymouth


___________________________________________________________________________________



5

using Batsound V3 software. Surveyors noted the species and activity of bats

they saw and heard.

2.5 Capture Surveys

Capture surveys were conducted on 16 May, 15 August and 2 September 2013

by the same surveyors6. Mist nets (2.6-12m x 2.6m Avinet bat nets) were set

across tracks and rides to capture commuting bats. A two bank harp trap (2.4 x

1.8 m Austbat) was used. An acoustic lure7 (Sussex AutoBat and/or Petterson

D1000x) was used an hour after sunset to attract bats into more cluttered areas

of vegetation.

Capture sites were focussed in two areas at the south and west of the site.

These included an area of former water meadows and woodland edge (capture

site 1) and an area of coniferous woodland (capture site 2). Nets were set in two

locations within each site. Between 8 & 9 nets and one harp trap were erected on

each survey evening. Surveys avoided the peak maternity season (June/July) to

avoid stressing pregnant or lactating bats. The two capture sites are shown on

Map 2.

Time of capture, species, sex, sexual status, weight and forearm measurements

were recorded for each bat. Tragus width and thumb length were recorded for

long-eared bats (an aid to the separation of brown and grey long-eared bat

species). All bats were released at the place of capture.

The use of mist nets, harp trap and acoustic lure were under licence WML CL19

& WML CL20 (levels 3 & 48) registration number CL502415.

Although the surveys focussed on capturing bats, surveyors also made informal

records of any bats heard on detectors. These results are shown on Maps 3a &

3b.

2.6 Survey Limitations and Precautionary Approach to Evaluation

Bat detectors have limited ranges. The calls from some species such as

pipistrelle, noctule Nyctalus noctula and serotine Eptesicus serotinus bats are

more likely to be heard than quieter species such as long-eared bats and those in

the genus myotis.

6 Accompanied by Simon Weymouth or Jay Doyle.

7 Playing pre-recorded or digitally processed bat social calls through ultrasound speakers to attract bats

towards nets/harp trap this permits the capture of bats using these methods up to three times in any one year per site without the

need for a specific project licence


___________________________________________________________________________________



6

The first capture evening was unseasonably cold which almost certainly

influenced the very low bat activity levels.

Bats move roosts and frequently alter foraging areas according to a number of

factors including time of year, weather, seasonal availability of food sources and

temperatures. Each survey should therefore be seen a ‘snap shot’ in time.

Signs of bat roosting are rarely present outside a tree roost entrance. Resources

did not permit a detailed assessment of trees for potential roost features.


___________________________________________________________________________________



7

Capture site 2

capture site 1

North Transect

South Transect

Map 2 To show key features of the site and locations of the transects and capture sites


___________________________________________________________________________________



8

3.0 Survey Results

3.1 Data Search

DERC held a number of records for the following species: common pipistrelle

Pipistrellus pipistrellus, soprano pipistrelle Pipistrellus pygmaeus, unidentified

pipistrelle Pipistrellus sp., long-eared bat Plecotus sp., brown long-eared bat

Plecotus auritus, noctule, serotine, Daubenton’s bat Myotis daubentonii,

unidienfied myotis sp. ‘myotis sp.’ and simply ‘unidentified bats’. Roost sites were

recorded for both common and soprano pipistrelle, brown long-eared bats. No

records were held for Bechstein’s bat and no roost records were held for serotine

bat.

3.2 Site Assessment

This is detailed in Section 4.2.

3.3 Evening Transect Surveys

3.3.1 28 June 2013 (sunset 21.24)

North Transect

Three species were encountered. Common and soprano pipistrelle bats were

heard commuting and foraging throughout the area with bats focusing along

tracks and rides. Four serotine bat passes were heard in two areas in the centre

and southern part of the transect.

South Transect

A greater diversity of species was encountered in the southern transect with six,

possibly seven species recorded. Common and soprano pipistrelle bats were

heard throughout the survey area with serotine bats focused more towards the

southern end. A noctule bat pass was also heard. Bats in the genus myotis

including one Daubenton’s Myotis daubentonii bat were heard at the far western

end of the transect near the Moors River and meadows. Two other ‘myotis’

recordings were made, one with a broadband call which may have been a

Natterer’s bat Myotis nattereri, the other with a narrowband call. A small number

of long-eared bat passes were also heard within the area.

Four small bats were seen at the beginning of the transect near the Matchams

Lane car park between 21.37 and 21.45. Their size suggested that the species

could only be pipistrelle, small myotis species or lesser horseshoe Rhinolphus

hipposideros bats. All of these species emerge relatively early in the evening.

The slow agile flight around low vegetation suggested that they were not


___________________________________________________________________________________



9

pipistrelle bats. Their early arrival suggests that they were roosting nearby.

Recordings could not be made as the bats were not echolocating.

3.4 Capture Surveys

3.4.1 16 May 2013

Seven mist nets and a harp trap were set at capture site 1 in the field east of the

river and the adjacent woodland edge. Bat activity levels were extremely low with

only a few common and soprano pipistrelle bat passes heard and no bats

captured. The temperatures dropped quickly which no doubt curtailed activity.

The following days were also cold after a brief warm spell in an otherwise wet

spring.

Table 1 Results of Capture Survey 16 May 2013

Mist net survey Hurn (16.05.2013)

Sunset: 20.51 Temp: 9.7-7.1 Cloud: 10 Wind: 0

End: 00.00 Surveyors: Colleen Hope, Paul Hope, Simon Weymouth

Time Species Sex Status F/Arm Weight (g) Thumb Tragus Other

no bats captured

During the surveys a noctule was seen and heard foraging above the field shortly

after sunset (21.10) suggesting it may have been roosting nearby. Between one

and two common and soprano pipistrelle bats foraged over the field and adjacent

woodland edge throughout the survey period.

3.4.2 15 August 2013

Eight mist nets and a harp trap were set near the Matcham’s Lane carpark

towards the south of the site at capture site 2. Two adjacent locations were

chosen which included the area where four non echolocating bats had been seen

during the transect survey. These bats were not encountered during this August

survey. Four species were captured including a juvenile noctule, two serotine,

two brown long-eared and one juvenile Natterer’s bats. One of the serotine as

well as both brown long-eared bats were parous (breeding) females. The

serotines were heard early in the evening suggesting they were roosting very

nearby, almost certainly in a building. Brown long-eared bats have a small range

normally within 1km of their roost sites and so this species is also likely to have

been roosting nearby.


___________________________________________________________________________________



10

A soprano pipistrelle bat was heard shortly after sunset at 20.20 which must have

been roosting nearby. Other than the species captured no other bats were heard.

Table 2 Results of Capture Survey 15 August 2013


Sunset: 20.26 Temp: 19-17.8 Cloud: 0 Wind: 0

End: 23.30 Surveyors: Colleen Hope, Paul Hope, Simon Weymouth

Time Species Sex Status F/Arm Weight (g) Thumb Tragus Other

21.15 Nn m juvenile 52.4 28

22.30 Mn m adult 39 9

21.00 BLE f P 37.1 8 7.4 5.1

21.00 BLE f P 5.1 6.4

21.40 ES f P 51.3 22

21.40 ES m adult 54.5 20.5

Species code: Pa = Plecotus auritus, W/B = Myotis brandtii/ mystacinus, Pip = Pipistrellus sp,

Mn= Myotis nattereri, Mbec= Myotis Bechsteinii, ES=Eptesicus serotinus, Nn=Nyctalus noctula

Status code: p= parous, np= nulliparous, lac= lactating, a = Adult, j =juvenile

3.4.3 2 September 2013

Seven mist nets and a harp trap were set at capture site 1. Again activity levels

were low with only a few common and soprano pipistrelle bat passes heard. A

single adult male Bechstein’s bat was captured at 21.35 along the woodland edge

part of the site (see Photo 1).

The only other bats encountered throughout the evening were a single or small

number of common pipistrelle and one long-eared bat.


___________________________________________________________________________________



11

Table 3 Results of Capture Survey 2 September 2013


Sunset: 19.50 Temp: 16.3-11.2 Cloud: 10 Wind: 0

End: 23.00 Surveyors:

Colleen Hope, Paul Hope, Jay Doyle

Time Species Sex Status F/Arm Weight (g)

Thumb Tragus Other

21.35 Mbec m adult 41.1 9.5

Species code: Pa = Plecotus auritus, W/B = Myotis brandtii/ mystacinus, Pip = Pipistrellus sp,

Mn= Myotis nattereri, Mbec= Myotis Bechsteinii, ES=Eptesicus serotinus, Nn=Nyctalus noctula

Status code: p= parous, np= nulliparous, lac= lactating, a = Adult, j =juvenile

Photo 1 Bechstein’s bat caught in September 2013.


___________________________________________________________________________________



12

4.0 Evaluation

4.1 Species Accounts

Table 4 below shows the status and distribution of the bat species encountered at

Hurn.

Table 4 To Show Status and Distribution of Bats in the UK (combined data from 9JNCC & 10IUCN).

Common name

Scientific name

Status JNCC Distribution JNCC

Status and population trend IUCN

Common Pipistrelle

Pipistrellus pipistrellus

common widespread LC stable

Soprano Pipistrelle

Pipistrellus pygmaeus

common widespread LC unknown

Brown Long eared bat

Plecotus auritus

common widespread LC stable

Daubenton’s bat

Myotis daubentonii

common widespread LC unknown

Natterer’s bat Myotis nattererri

frequent widespread LC stable

Noctule bat Nyctalus noctula

frequent frequent LC unknown

Serotine bat Eptesicus serotinus

frequent restricted LC unknown

Bechstein’s bat

Myotis bechsteinii

rare restricted NT decreasing

NT not threatened LC least concern

Annex 3 provides details of the basic ecology and habitat preferences of each of

the bat species recorded at Hurn.

Key to Maps 3a & 3b

Pp common pipistrelle

Ps soprano pipistrelle

ES serotine

Nn noctule

M myotis sp.

9 JNCC Habitat Management for Bats (2000)

10IUCN Red data list of threatened species (2008)

Md Daubenton’s

Mn Natterer’s

Unid unidentified bat (seen not

heard)

LE long eared

(f) foraging

(c) commuting

(s) social calling


___________________________________________________________________________________



13

Map 3a Results of North Transect 28/6/2013

Pp (c) 23.05

Ps (f) 23.07

Ps (f) 23.10

Pp (c) 22.43

2 x Pp (f) 22.34

Pp (c) 22.30

Ps (f) 22.16

ES 22.07 & 22.10 (c)

Ps (c) 22.02

2 x Pp (f) 21.54

Pp 21.50

Pp (c) 23.24 Ps (c) 23.47

ES 23.42 & 23.50 (c)

Date: 28/6/2013 Sunset time: 21.20

Surveyor/s: Paul Hope

start end

Start/end time 21.41 23.25

temperature 16.4C 16.4C

Cloud cover % 100 100

precipitation 0 0

wind 1 1

Species encountered:

Common pipistrelle, soprano pipistrelle,

serotine


___________________________________________________________________________________



14

Map 3b Results of South Transect 28/6/2013

Pp 23.28 ES 23.30

ES 23.15

M/LE 23.16

4 x Unid 21.37-21.45 Nn 12.40 2 x Pp 21.40

ES 21.53 Pp 21.53

Pp 22.06 ES 22.08

Pp 22.24

Ps & Md 22.25

M (Mn?) 22.30

Pp (f) 22.37

Pp & Ps (f) 22.47 Pp & Ps (f) 22.50

2 x LE 22.40 Pp 22.40

M 22.52

Pp (f) 22.59

Date: 28/6/2013 Sunset time: 21.20

Surveyor/s: Colleen Hope/Simon

Weymouth

start end

Start/end time 21.40 23.40

temperature 17C 17C

Cloud cover % 100 100

precipitation 0 0

wind 0 0

Species encountered:

Common pipistrelle, soprano pipistrelle,

serotine, noctule, myotis sp,

Daubenton’s, long-eared, unidentified

bat sp.


___________________________________________________________________________________



15

4.2 General Site Evaluation

4.2.1 Overview of Habitats

The majority of the woodland in the site is coniferous plantation. Much of this is of

a similar age and there are large tracts of woodland where tree cover has

suppressed the shrub (field) and ground layers. This has resulted in a

homogenous habitat with limited species or structural diversity. In turn this limits

the diversity and numbers of invertebrates (upon which bats feed). The bat

species which are associated with open areas and edge habitats such as noctule,

serotine, Leisler’s Nyctalus leislerii and pipistrelle bats are more likely to utilise

the wide woodland rides and track as well as the woodland/heathland edge and

open habitats. Not surprisingly noctule, serotine and pipistrelle bats were all

common and reasonably widespread during the surveys.

Species such as long-eared, horseshoe bats and those in the genus myotis are

strongly associated with more dense woodland habitats where they are able to fly

amongst vegetation and in some cases ‘glean’ insects off the leaves. These

species thrive best in deciduous or mixed woodland particularly where a dense

and diverse understorey shrub layer is present. These habitats are lacking at

Hurn Forest; they are limited to the edges (particularly the western edge near the

Moors River) and a few wetter areas where streams run across the site. It is

probably no coincidence that the greatest diversity of bats captured and heard

during the surveys were in the areas with more diverse and dense shrub layer.

4.2.2 Foraging Habitats & Commuting Routes

There were no particularly well defined foraging areas identified during the

transects. Pipistrelle bats tended to utilise all suitable areas but were not found in

any areas in great densities. This probably reflects the homogeneous habitat

which does not provide focal sites for invertebrates.

Surprisingly the activity levels were also relatively low along the water’s edge.

This was evident not only during the transects but also during the capture

surveys.

Three to four serotine bats foraged north and south of the car park near

Matcham’s Lane for most of the survey period in August. Serotine bats were

heard on both transects. The early registrations for this species at capture site 1,

parous female caught in August and early registrations at the beginning of the

south transect strongly suggest that a maternity roost was present nearby,

possibly within 0.5km of Matcham’s car park. The activity and results of the


___________________________________________________________________________________



16

capture surveys suggest that there is also a maternity brown long-eared bat roost

nearby.

Pipistrelle and serotine bats commuted along woodland rides and tracks to some

extent but no clearly defined commuting routes were identified. This is probably a

reflection of the relatively small number of individual bats using the site. It should

also be noted that due to the quiet echolocation call of long-eared bats, their

commuting routes are harder to detect.

4.3 Assessment of Specific Habitat Types

4.3.1 Coniferous Woodland, Tracks & Rides

This is the dominant habitat within the site with Scott’s pine Pinus sylvestris &

Corsican pine Pinus nigra spp. the most commonly occurring species. As already

noted, its even age and structure result in limited foraging opportunities for bats

(see Photo 2). The tracks and rides are used by commuting pipistrelle and

serotine bats moving between foraging areas. They are also used by these ‘edge

habitat’ specialists as foraging sites in themselves. The most valuable tracks and

rides are those where light has reached and stimulated growth in the field layer

resulting in small shrubs and bushes which in turn support invertebrates (see

Photo 3 shows a more diverse edge to one of the rides (although this could be

improved further). Wetter areas also support more invertebrates (for example the

area immediately north of capture site 1).

More mature trees with signs of damage such as split or twisted trunks, limbs,

areas of rot or flaking bark provide potential roost sites for bats. Cavities

accessed by woodpeckers also provide roost sites for bats. All of these features

are limited in Hurn Forest.

Photograph 2: Homogenous stand with little structure along ride edges

Photograph 3: This ride has a more diverse edge with heather in the ground layer. It could

still be improved by selective thinning and possibly planting a shrub layer.


___________________________________________________________________________________



17

4.3.2 Deciduous woodland

This habitat is fairly limited in Hurn Forest. Although some planted mixed

woodland is present deciduous trees are mainly focused around the edges of the

coniferous woodland stands where trees have self sown (see Photo 4). These

trees still tend to be quite young and so although providing more structural

diversity there are few trees which are mature enough to support roost features.

Deciduous trees are also more prevalent along the sides of the watercourses

(e.g. silver birch Betula pendula and willow Salix sp.), some of which traverse the

site. These areas are potentially valuable bat foraging habitats in the context of

the more homogenous coniferous woodland.

4.3.3 Moors River & Adjacent Meadows

Although there is more structural diversity and there are wetter conditions along

this western perimeter (see Photo 5) the bat activity levels recorded during the

capture surveys and transects were surprisingly low. This may not be easily

explained (although one of the evenings was unseasonably cold). A large part of

the area to the west of the river corridor is open and dominated by the airport.

This lack of habitat may play a role in reducing activity in the area adjacent to it.

4.2.6 Heathland

Bats were recorded over the more open areas of heathland although this was

limited to pipistrelle and serotine bats. Few recordings were made of noctule bats

suggesting that a significant roost was not present nearby when the surveys were

conducted. Noctule bats favour more open areas for foraging and heathlands

provide good numbers of invertebrates.

Photograph 4: Woodland edge at capture site 1. Location of captured Bechstein’s bat

Photograph 5: Wetter habitat along field edge adjacent to Moors River at west of

site.


___________________________________________________________________________________



18

Although the open nature of the heathland may not suit many species of bats it

may be an important source of invertebrate food which then migrates to the

woodland/healthland edges where it becomes more available.

Photograph 6: Heathland edge with open area in the background at Hurn Forest.


___________________________________________________________________________________



19

5.0 Recommendations

5.1 Habitat Diversity

A long-term approach should be taken to diversify the age structure of some of

the trees by selective thinning/felling. Any new planting should be of deciduous

trees with the aim of increasing not only the diversity of the standard trees but

that of the under storey species.

Some individual trees may be selected for ring barking11. This eventually kills the

tree and provides standing deadwood habitats which encourage a diversity of

invertebrates (particularly beetles). It may also attract woodpeckers which create

holes which bats may use to access cavity roost sites. Flaking bark may also be

used by bats as a roost sites.

5.2 Tracks and Rides

Many of the tracks and rides are straight in plan view with abrupt vertical sides

showing little structural diversity. A varied ‘edge’ habitat is valuable for bats and

should be encouraged by creating meanders and bends in tracks and rides where

possible. This not only effectively increases the total length of the ‘edge habitat’

but prevents the track/ride acting as a wind tunnel. The structure of the tracks

and rides should be diversified by cutting back some of the edge trees and

encouraging or planting a field layer. This will encourage light and in turn more

vegetation and invertebrates and consequently food for bats.

11

Ring barked trees will eventually die and become unstable. They should be sited away from areas used by the public

Photograph 7: More varied structure to track edge (Fox Hunting Inclosure New Forest) with bracken and bramble grading into

holly and yew with standard trees (beech, pine and fir)


___________________________________________________________________________________



20

5.3 Glades

Glades mimic areas around fallen veteran trees which in the past would have

been a natural dynamic of the woodland ecosystem. There are few glades within

any of the woodland blocks at Hurn Forest. Creating glades is another means of

increasing ‘edge habitat’ and species/structural diversity within woodland blocks.

A series of glades should be created in the homogenous woodland stands at

Hurn Forest. Ideally a woodland management plan should show how these will

eventually be linked to one another through subsequent selective thinning or

felling.

5.4 Water bodies

The wetter areas are valuable as they provide a greater diversity in both the

canopy and field layers. Many invertebrates also require water to breed. Any

opportunities to create new ponds should be taken. Networks of smaller ponds

are generally more valuable for species than single large bodies of open water.

5.5 Bat Boxes

Artificial roost sites can be created using bat boxes. Hurn Forest offers

comparatively few potential roost sites in trees and so these could offer a

valuable conservation method for habitat creation.

5.6 Community Involvement

Dorset Bat Group should be approached and their members encouraged to get

involved in the proposals. Most bat groups will be able to monitor sites e.g.

checking bat boxes and giving guided walks for the public. They rely on

volunteers and so a small contribution may be offered to cover expenses. Help

promoting public walks is also normally appreciated.


___________________________________________________________________________________



21

Figure 1 To illustrate positive woodland management principals in coniferous woodland

(extract from JNCC, Habitat Management for Bats (2001)


___________________________________________________________________________________



22

6.0 Conclusions

Seven bat species have been recorded within Hurn Forest during surveys in

2013. Most of these are common and nationally or locally widespread species

adapted for open or ‘edge’ habitats. The woodland habitats available within the

site are rather homogeneous in structure with low plant species diversity. A large

proportion of the site is open healthand. This results in a landscape which is

dominated by open and edge habitats. Potential roosting sites in trees on the site

are limited.

Notwithstanding this, a male Bechstein’s bat was captured along one of the more

diverse woodland edges and breeding brown long-eared (and serotine) bats are

apparently foraging in the more diverse woodland habitat towards the south of the

site.

There are good opportunities for improving the tree/shrub species and structural

diversity of the site without undertaking major woodland management works. By

altering the nature of rides and tracks and creating glades the number and

diversity of invertebrates will increase which will in turn benefit bats. Bat boxes

could also be erected to provide new roosting sites.

The recommendations made in this report will benefit a range of other species

such as birds, small mammals (including dormice if present), reptiles and

amphibians. The increased biodiversity and the more varied visual experience

will also enhance the site for the local community as well as visiting public. This

in turn could have the added advantage of reducing pressure from some of the

more sensitive sites such as the adjacent New Forest and Dorset Heaths.


___________________________________________________________________________________



23

7.0 References

Bat Conservation Trust (2012) Bat Surveys-Good Practice Guidelines 2nd Ed

Bat Conservation Trust Species information leaflets – various (2005)

Boonman M Roost selection by noctules (Nyctalus noctula) and Daubenton’s bats

(Myotis daubentonii) Journal of Zoology (2000)

Davidson-Watts I & Jones G Differences in foraging behaviour between

Pipistrellus pipistrellus (Schreber, 1977) and Pipistrellus pygmaeus (Leach, 1825)

(Journal of Zoology (2005)

Davidson-Watts I, Walls S & Jones G Differences in habitat selection by

Pipistrellus pipistrellus & Pipistrellus pygmaeus identifies distinct conservation

needs for cryptic species Biological Conservation (2006)

Fitzimmon P, Hill D & Greenaway F Patterns of habitat use by female

Bechstein’s bats (Myotis bechsteinii) from a maternity colony in a British

woodland (2002)

Gloor S, Stutz Hans-Peter B, & Zisinler V Nutritional habitats of the noctule bat

Nyctalus noctula (Schreber 1774) in Switzerland Myotis (1995)

Hope PR & Jones G Warming up for dinner: torpor and arousal in hibernating

Natterer’s bat (Myotis naterreri) studied by radio telemetry. Journal of

Comparative Physiology (2012)

The Conservation (Natural Habitats &c.) (England & Wales) Regulations 2010 (as

amended).

Institute for Ecology and Environmental Management (IEEM). (2006). Guidelines

for Ecological Impact Assessment in the United Kingdom. Approved Version 26

June 2006. IEEM Document.

JNCC (2000) Habitat Management for Bats

National Planning Policy Framework (April 2012) Department for Communities &

Local Government


___________________________________________________________________________________



24

Natural England Bat Mitigation Guidelines (2004)

Natural England Bat Workers Manual, 3rd Ed (2004)

Natural England website: http://www.natural-

england.org.uk/regions/east_of_england/ourwork/standingadvice/protectedspecie

s/bats.aspx

Natural England (2009) WML-G12-EPS Mitigation Licensing-How to Get a

Licence – Version 5

ODPM (2006) Planning for Biodiversity and Geological Conservation: A Guide to

Good Practice Office of the Deputy Prime Minister

Planning Policy Statement 9: Biodiversity and Geological Conservation Office of

the Deputy Prime Minister. June 2009 ODPM (2005)

Racey P & Swift S Feeding ecology of Pipistrelleus pipistrellus during pregnancy

and lactation .I. foraging bechaviour Journal of Animal Ecology (1985)

Robinson M F & Stebbings RE Home range and habitat use by the serotine bat,

Eptesicus serotinus, in England J Zoology (1997)

Robinson M F & Stebbings RE Activity of the serotine bat, Eptesicus serotinus, in

England Myotis (1997)

Siemens B & Swift S Differences in sensory ecology contribute to resource

partitioning in the bats Myotis bechsteinii and Myotis naterreri (Chiroptera:

Vespertilionidae) Behavioural Ecology & Sociobiology (2005)

Yalden D The history of British Mammals Poyser Natural History (1999)


___________________________________________________________________________________



25

Annexes


___________________________________________________________________________________



26

Annex 1 Legislation & Policy

Legislation

The two key pieces of legislation affording protection to bats and their roosting

sites are the Conservation of Habitats and Species Regulations 2010 (as

amended)12 and the Wildlife & Countryside Act 1981 (amended 2007).

Under the Conservation of Habitats and Species Regulations 2010 (as amended)

it is an offence to deliberately kill, capture or injure a European protected species,

or to damage or destroy the breeding site or resting place of such an animal.

Disturbance of a European protected species is also an offence if done in such a

manner as to be likely to significantly to affect:

(a) the ability of an EPS to survive, breed, or reproduce, or to rear or nurture

young, to hibernate or migrate; or

(b) the local distribution of that species.

All species of bat in the UK are European protected species (EPS) and thus

protected by this legislation. Because bats return to roost sites on a regular basis,

the roost site is considered to be legally protected even when the bat is not

present. If any activities relating to development which could result in any of the

offences above are undertaken it is necessary to obtain a licence from Natural

England (formerly issued by Department for Environment, Food and Rural Affairs,

DEFRA). In order for a licence to be granted the following conditions must be

satisfied:

� The proposal must be necessary ‘to preserve public health or

public safety or other imperative reasons of overriding public

interest including those of a social or economic nature and

beneficial consequences of primary importance for the

environment’;

� ‘There is no satisfactory alternative’;

� The proposals ‘will not be detrimental to the maintenance of

the population of the species concerned at a favourable

conservation status in their natural range’.

The Wildlife & Countryside Act (WCA) 1981 was amended by the recent changes

to the Conservation (Natural Habitats &c) Regulations 1994 (amended 2010).

The WCA also makes it an offence to intentionally or recklessly disturb bats to

obstruct access to roost sites, and to sell or advertise bats for trade. The

12

(referred to as the ‘Habitats Regulations’ and formerly the Conservation (Natural Habitats &c) Regulations 2010 (as amended), (England & Wales, as amended),


___________________________________________________________________________________



27

Countryside & Rights of Way Act 2000 (CROW) strengthened the WCA by adding

the word ‘recklessly’ to these offences.

The Natural Environment & Communities Act (NERC) 2006 states (s40) that

‘Every public body must, in exercising its functions, have regard, so far as is

consistent with the proper exercise of those functions, to the purpose of

conserving biodiversity.’

Section 40(3) also states that

‘conserving biodiversity includes, in relation to a living organism or type of habitat,

restoring or enhancing a population or habitat.’

Priority species are listed in s41 of the NERC Act. These include the

following bat species: soprano pipistrelle Pipistrellus pygmaeus, brown long-

eared bat Plecotus auritus, Bechstein’s bat Myotis bechsteinii, noctule

Nyctalus noctula, barbastelle bat Barbastella barbastellus and greater and

lesser horseshoe bats Rhinolophus ferrumequinum/ R. hipposideros.

Policy

The National Planning Policy Framework (NPPF) became effective on 27 April

2012. This sets out the Government’s planning policies for England & Wales and

how they should be applied. Although policies in local plans (and the London

Plan) should not be considered out-of–date simply because they were adopted

prior to the publication of the NPPF, the NPPF policies are material

considerations which local planning authorities should take into account. The

NPPF must also be taken into account during the preparation of local and

neighbourhood plans.

The NPPF effectively made Planning Policy Statement 9; Biodiversity and

Geological Conservation (PPS9) redundant. Circular 06/0513 remains an active

document to be used in conjunction with the NPPF rather than PPS914 15.

The main thrust of the NPPF is that is has a clear:

13

ODPM Circular 06/2005: Biodiversity and Geological conservation-Statutory Obligations and Their Impact within the Planning System (Circular 06/05). 14

The Government will “now embark on a new exercise to consider what underpinning guidance continues to be needed”. A timetable for this process has not as yet been set (May 2012) however “until such time as the guidance review is complete, the existing guidance where relevant can still b used.” 15

However, for 12 months from the day of the publication of the NPPF decision makers may continue to give full weight to the relevant polices adopted since 2004 (e.g. PPS9 & PDPM 06/05) even if there is a limited degree of conflict that the NPPF.


___________________________________________________________________________________



28

“presumption in favour of sustainable development, which should

be seen as a golden thread running through both plan-making

and decision-taking.” (Para 4)

With regard to protecting the natural environment, planning should still enhance

the natural environment and where possible provide net gains for biodiversity16.

Para 118 states that:

“Opportunities to incorporate biodiversity in and around

developments should be encouraged”

and that planning policies should

“ promote the preservation, restoration and re-creation of priority

habitats, ecological networks and the protection and recovery of

priority species populations, linked to national and local targets,

and identify suitable indicators for monitoring biodiversity in the

plan” (Para 117).

The NPPF states that with regard to conserving the natural environment the

planning system should contribute to and enhance the natural and local

environment by:

• protecting and enhancing valued landscapes, geological

conservation interests and soils;

• recognising the wider benefits of the ecosystem services;

• minimising the impact on biodiversity and providing net gains in

biodiversity where possible, contributing to the Government’s

commitment to halt the overall decline in biodiversity, including by

establishing coherent ecological networks that are more resilient to

current and future pressures;

• preventing both new and existing development from contributing

to or being put at unacceptable risk from, or being adversely

affected by unacceptable levels of soil, air, water or noise pollution

or land instability; and

• remediating and mitigating despoiled, degraded, derelict,

contaminated and sustainable land, where appropriate.” (Para

109)

Section 11 of the NPPF (Conserving and enhancing the natural environment)

also identifies how planning policies should plan for biodiversity at a landscape

scale, and take an active role in promoting and enhancing (and re-creating)

16

The NPPF also emphasises the importance of ecosystem services and soils.


___________________________________________________________________________________



29

priority habitats and ecological networks as well as protecting and supporting the

recovery of priority species populations.

Species and habitats listed in UK BAPs were identified as priority consideration

for biodiversity conservation by public authorities through Sections 40-42 of the

NERC Act 2006) in England and Wales. ‘Biodiversity 2020: A Strategy for

England’s Wildlife and Ecosystem Services (2011)’ replaced the previous

‘England Biodiversity Strategy’. The ‘UK BAP’ was also replaced with the ‘UK

Post-2010 Biodiversity Framework (2012)’. Biodiversity issues are now devolved.

What are still sometimes referred to as ‘BAP species’ and ‘BAP habitats’ are now

referred to as ‘Species and Habitats of Principal Importance for Conservation in

England’, (or simply ‘Priority Species’ and ‘Priority Habitats’). This list of habitats

and species remains unchanged and is still derived from S41 of the NERC Act

(2006). Consequently these species and habitats are a material consideration for

planning purposes.

Priority species listed on S41 of the NERC Act include the following bats:

soprano pipistrelle Pipistrellus pygmaeus, brown long-eared bat Plecotus auritus,

Bechstein’s bat Myotis bechsteinii, noctule Nyctalus noctula, barbastelle bat

Barbastella barbastellus and greater and lesser horseshoe bats Rhinolophus

ferrumequinum/ R. hipposideros.


___________________________________________________________________________________



30

Annex 2 Surveyor Experience

Colleen Hope (nee Mainstone), BSc, MCIEEM

Director, Ecological Consultancy Services Ltd.

I am joint Director of Ecological Consultancy Services Ltd (ECS), a locally based

ecological consultancy which I established in 2008. Prior to this I was employed

in a senior role at a consultancy based in Winchester for six years.

ECS employs two permanent staff who undertake surveys for a wide range of

protected species including reptiles, great crested newts, dormice, otters, water

voles, bat and barn owls. ECS specialises in surveying and assessing sites for

bats.

ECS has a wide client base including local authorities, the Environment Agency,

Forestry Commission, National Trust and large, small and medium sized planning

consultancies. ECS also provides specialist bat survey services to other

ecological consultancies mainly with regard to Environmental Impact

Assessments (EIA).

I hold Natural England survey licences (levels 3 & 4) and am licenced to train

individuals to licence level. I have successfully obtained over 55 DEFRA/Natural

England EPS (bat) development licences for a range of sites including modern

and historic buildings, barns, trees, large scale new town developments, wind

farms and road schemes. I am a Registered Ecological Consultant under Natural

England’s Trial Low Impact Licence scheme.

Over the last 12 years I have managed a number of county and borough wide bat

surveys including a capture, ringing and radio tracking study into the distribution

of Bechstein’s and barbastelle bats in the New Forest, Hampshire. Bat survey

work has taken me overseas to India, Burma (Myanmar) and Vietnam.

Dr Paul Hope, BSc (Hons), MCIEEM

Director, Ecological Consultancy Services Ltd.

Paul is also joint Director of ECS and based in Romsey, Hampshire. He

undertakes site appraisals for a range of species including reptiles, badgers,

watervoles, dormice and species and specialises in surveying for bats.

Paul has held Natural England bat survey licences for over 12 years and has 8

years experience undertaking a range of surveys for both bats and reptiles. He is

licenced trainer for Natural England (Conservation licences) and also trains

consultants for bat survey licences.


___________________________________________________________________________________



31

Paul is just completed a part time PhD at the University of Bristol studying the

hibernation ecology of British bats. He has extensive experience in the collection

and analysis of field data using of a range of monitoring devices including bat

detectors (time expansion, frequency division and heterodyne), infrared motion

sensors and radio telemetry equipment for receiving and data logging.

During the process of surveying for environmental impact assessments both Paul

and I have undertaken radio tracking and ringing studies of seven bat species.

We each have over 1000 hours radio tracking experience radio tracking a range

of bat species in relation to impact assessments for development and providing

information for bat conservation.


___________________________________________________________________________________



32

Annex 3 Status & Distribution of Species Encountered

Common & Soprano pipistrelle

Common and soprano pipistrelle bats are common and widespread throughout

the UK and most of Europe (BCT, 2003). They are morphologically cryptic

species, however in most cases they can be identified by their echolocation calls

at 46 & 55 KHz respectively. Racey & Swift (1985) radio tracked pregnant and

lactating common pipistrelle bats in a lowland agricultural area with extensive

foraging resources and by contrast an upland area with less available resources.

The mean distance flown by pregnant bats in the agricultural landscape was

1.8km between roost sites and foraging areas with a maximum distance of 5.1km.

Distances were reduced to 1.3 and 3.7km respectively during the lactation period.

Distances travelled in the upland area averaged 1km with a maximum of 2.5km in

both the pregnancy and lactation periods.

Racey & Swift observed that bats moved along a regular route and were sighted

at the same place and the same time on successive nights. Individual foraging

beats were rarely defended with large numbers of bat foraging in small areas

where insect densities were high. Foraging beats were usually over water, along

hedgerows or around individual trees.

Davidson Watts, Walls & Jones, (2006) demonstrated different habitat

preferences between the two species. Soprano pipistrelle bats favoured riparian

habitats over all other potential habitats and foraged mainly on flies with an

aquatic larval stage whilst common pipistrelles were more generalist foragers

including a wider range of dipteran families in their diet and foraging more widely.

Compositional analysis was used to show and rank the preferred habitat used by

each species (>>> reflects a significant difference between adjacent habitats).

Common pipistrelle favoured deciduous woodland>grassland>riparian>suburban

mixed woodland>arable>>conifer woodland.


___________________________________________________________________________________



33

Soprano pipistrelle favoured riparian woodland>riparian grassland>>>deciduous

woodland>suburban>>>mixed woodland>conifer>arable

Davidson Watts & Jones (2005) found that common pipistrelle bats made more

flights to a greater number of foraging areas that soprano pipistrelle bats however

the distances travelled by common pipistrelle bats was shorter. The larger

distances flown by soprano pipistrelle bats probably reflected its selectivity in

foraging areas techniques.

The average colony size of common pipistrelle bats in the UK is estimated to be

between 68 bats. The average colony size of soprano pipistrelle bat in the UK is

estimated to be between 288 (BCT, 2005).

Noctule bat

The status and distribution of noctule bats in the UK is described as ‘frequent’

occurring throughout England and Wales and southern Scotland although they

are scarce in intensively agricultural areas. Noctule bats are a one of the largest

species in the UK. Their narrow wings allow them to fly fast (30mph/50kph) and

cover large distances in a short period of time; they may commute between 6km

and 10km between roost and foraging sites (BCT, 2005). They are one of the

first species to emerge and can be seen in almost daylight; they often forage for

the first two hours after dusk before returning to the roost and foraging again for

approximately 30 minutes at dawn. Their favoured habitats are deciduous

woodland, parkland, pasture, water bodies and forest edges (BCT, 2005).

Noctule bats forage on insect swarms in summer often forming large groups of

bats that employ a filter feeding technique. Insects remains found in droppings of

noctule bats in a study in Switzerland revealed trichoptera and diptera families


___________________________________________________________________________________



34

many of which have a larval stage dependent upon water. In spring and autumn

noctule forage on larger beetles (Gloor, Stutz & Ziswiler, 1995). Noctule bats are

often seen foraging over water bodies and are confident flying away from

vegetation.

Roost sites are almost exclusively in trees in the UK although buildings are used

on the continent. Boonman (2000) studied 81 noctule summer roosts in the

Netherlands and found a strong holes but to a lesser extent). Roost sites were

close to woodland edges probably to reduce commuting journeys to foraging sites

but also for thermoregulatory reasons.

In April, mixed sex roosts are evident but males form solitary roosts in

midsummer. In autumn males call loudly from mating roost sites. Females will

move maternity roosts frequently even carrying young with them.

Noctule bats are a migratory species in Europe and Russia although solitary,

mixed sex hibernation roosts are known which include individuals from several

different summer colonies (Petit & Meyer, 2000 cited in Harris & Yalden (2008).

The average colony size of noctule bat in the UK is estimated to be between 15-

50 with occasionally up to 100+ (BCT, 2005).

Serotine bat

Serotine bats are frequent and restricted in the UK, mainly south below a line

from the Wash. They may be moving their range northwards but there are

reported declines of this species from south eastern counties such as Sussex and

Hampshire; recent concern for their status has led to a species conservation

group forming in southeast England. A biodiversity action plan was drawn up for

serotine bats in neighbouring Hampshire in 2002 after a county wide review of all

known records by Hampshire Bat Group suggested that numbers had declined

(Mainstone unpub.)

Serotine bats are one of the largest species of bat in the UK. They have broad

wings, a highly manoeuvrable flight and forage in ‘edge’ habitats; they are equally


___________________________________________________________________________________



35

happy foraging over relatively open areas of grassland and can often be seen

foraging around streetlamps on insects attracted to these areas. Favoured

habitats include parkland, leafy suburban areas, pasture and open woodland

areas (BCT 2008). Robinson & Stebbings studied the foraging behaviour of

serotine bats in 1989 and recorded all foraging sites to be within 300m of pasture

or woodland which they considered to be vital habitat for this species survival.

Bats spent 83% of their time foraging over pasture and woodland (43.6% over

woodland and 39.6% over pasture). Serotine bats feed mainly on moths and flies

in springtime favouring dung beetles and chafers in summer. Robinson &

Stebbings (1997) recorded bats visiting between 0-10 feeding sites per night

when bats commuted along hedgerows, tree lines and over pastures. In a study

by Catto (1996) bats travelled an average 6.5km between foraging sites using up

to 5 sites per night with higher foraging ranges in predominantly arable areas.

Harris & Yalden (2008) cite serotine bats flying close to trees, particularly the

canopy and along hedgerows, street lights and occasionally feeding well within

beech woods. They describe a slow and manoeuvrable flight often close the

ground or up to 10m with sudden steep dives.

Serotine bats emerge early from the roost sites, between 10-40 minutes of dusk

(BCT, 2005); Robinson & Stebbings (1997) recorded a mean time of emergence

as 22.1 minutes after sunset. Bats return to the roost to feed their young

frequently during the lactation period. Robinson & Stebbings (1997) radio tracked

serotine bats and recorded a single bout of feeding for about 90 minutes in May

and June (early gestation) with a bimodal pattern in July and August (post

lactation period); 140 minutes foraging was typical. Bats returned to the roost

during the lactation period but after lactation remained in temporary night roosts.

From early September and October activity was confined to a single short period

after dusk. Adults entered hibernation early for most bats in September or

October followed slightly later by juveniles.

Roost sites are almost exclusively in buildings with older buildings favoured and

access points often at gable eaves (BCT, 2005). Little is known about the mating

strategy or hibernation of this species.

The average colony size of serotine bat in the UK is estimated to be between 15-

30 (BCT, 2005).


___________________________________________________________________________________



36

Daubenton’s bat

Daubenton’s are a medium sized bat in the genus myotis which roosts in trees,

buildings and other structures (often bridges). Strongly favouring humid sites,

they have a strong association with water bodies and can be seen foraging over

open stretches of water (BCT 2008). Daubenton’s bats forage manly with 6km

of the roost site (occasionally up to 10km). They forage in woodland but

frequently over water where they trawl emerging insects from the water surface

with their large feet. Their diet consists largely of chironomid midges, mayflies

and caddisflies (BCT, 2008).

Male and non breeding female bats may congregate in summer communal roosts

or occasionally within maternity roosts. Sexual segregation of roosts sites has

been shown in studies of Daubenton’s bats on Yorkshire Rivers. While studying

27 Daubenton’s summer roosts in the Netherlands Boonman (2000) found a

strong preference for roost sites just within woodland edges with oak trees

preferred over beech. All roost locations were in cavities accessed by rot or

woodpecker holes.

The average colony size of Daubenton’s bat in the UK is estimated to be between

20-50 with occasionally up to 200+ (BCT, 2008).


___________________________________________________________________________________



37

Natterer’s bat

Natterer’s bats are frequent and widespread throughout the UK. The UK may be

internationally important for this species (BCT, 2003). Natterer’s bat is a medium

sized species within the genus myotis. It forages using low searching flight,

hovering, capturing insects in the tail membrane and consuming prey at feeding

perches or on the wing (Swift & Racey, 2002). Swift & Racey studied the foraging

strategy of this species and found that their main prey items were medium sized

arthropods particularly dung beetles, spiders, harvestmen and beetles with a few

moths. They also noted that Natterer’s and brown long-eared bats utilised similar

habitats but long-eared bats used passive listening as a foraging technique and

favoured ‘noisy’ insects whilst Natterer’s were able to exploit quiet insects by

using echolocation as the primary foraging technique. They also recorded

Natterer’s bats landing and pursuing prey on the ground.

In a foraging study of this species, Swift & Racey found Natterer’s bats moved

roosts every few days, often using a number of roosting locations in any site.

67% of roost sites were in trees (mostly oak or ash) with roof mortice joints in

attics and barns, soffits, crevices in walls, apices of eaves and a modern cavity

wall also used. Foraging is mainly concentrated in core areas of up to 2km² with

roost density ranging from 7-15 per km². Swift & Racey concluded that the bats

required access to a large number of roosts with a range of temperatures

dependant on their reproductive state and energy requirements. Bats showed

high fidelity to roost sites in successive years.

Hope & Jones (2012) found that Natterer’s bat frequently arose from torpor during

hibernation period and that these arousals were timed with sunset. They

suggested that Natterer’s bat may take advantage of mild winter evenings to

forage.

The median emergence time after sunset for Natterer’s bat was 75 minutes in a

study by Jones & Rydell (1994), making them one of latest emerging species in

the UK. Like long-eared bats they appear to be light-shy and may be active and

flying inside a building roost for some time before emergence. When emerging


___________________________________________________________________________________



38

from trees they may remain around the roost tree or adjacent trees for some time

before venturing away from cover. Natterer’s bats roost in crevices in trees such

as splits and tears and in buildings using locations such as mortice holes and

splits in timbers and crevices between bricks or stonework or beneath tiles.

There may be very little evidence of roosting outside the roost site; which

combined with their late emergence in poor light their roost sites contributes to

the species frequently being overlooked.

The average colony size of the Natterer’s bat in the UK is estimated to be

between 20-100 with occasionally up to 100+ (BCT, 2005).

Bechstein’s bat

Bechstein’s bat is one of Europe’s rarest bats and is confined in the UK mainly to

the south of the country. It is widespread within its range which includes the

Iberian Peninsula to the Ukraine and is at the northern border of its range in the

UK. Although it is widespread in Europe, its populations are believed to be low

(although local densities can be high). Its population has declined throughout its

range and it is ‘vulnerable’ (IUCN, 2001). It was probably common in Neolithic

times when its woodland habitat was very much more widespread as fossil

remains in Grimes Graves in Norfolk suggest (Yalden, 1999).

Recent studies suggest that an ideal Bechstein’s wood is deciduous, uneven in

age, 40-50 hectares in extent and to be semi natural or ancient in origin with a

dense understorey and a watercourse. Bechstein’s colonies may also survive in

oak and mixed hardwood forestry plantations provided there are adequate

suitable roost sites and a dense understorey.

In the UK Bechstein’s bats show a significant preference for trees as roost sites,

although bat boxes have successfully attracted bats and there are a handful of

records of roosts in buildings. Roost sites are most commonly found in cavities

excavated by woodpeckers in oak Quercus sp. or beech Fagus sylvatica (or ash

Fraxinus excelsior on Isle of Wight).


___________________________________________________________________________________



39

Group sizes within maternity roost sites vary as individuals regularly split off and

regroup within the colony range. This constant ‘fission fusion’ behaviour makes

population estimates difficult but average colony size is believed to be 15-40

animals, maximum 80 (Kerth & Konig, 1999, Germany). The average roost size

of five maternity colonies studied in the New Forest between 2005-2013 has been

between 30-40 bats (pers obs.)

The core foraging area of individual female Bechstein’s bats is smaller than for

most other species of bat. The maximum distance between foraging area and the

main roost site of females during the West Sussex radio tracking study in this

study was 1.4km (Fitzimmons, Hill & Greenaway, 2002). The main prey items

of Bechstein’s bats are moths, flies, harvestmen, earwigs and crickets (Siemen’s

& Swift, 2005)

A UK population estimate of 1500 is quoted in Harris & Yalden (2008) but the

authors note that populations are difficult to assess because of the small number

of known colonies; they state that the population could be as great as 20,000 –

25,000.

Brown long-eared bat

Long-eared bats are a medium sized species differing from most Palaearctic

species in having broad wing and long ears. These morphological characteristics

allow them to hover in flight, listen for and glean insects (mainly moths) from

surfaces (Entwistle, Racey & Speakman, 1996). These features do however

result in a slow flight which makes them vulnerable to predation and this may be

why they are wary of flying across open spaces. Long-eared bats emerge from

roost sites later than most species when light levels are lower.

Long-eared bats appear to be light-shy and may be active and flying inside a

building roost for some time before emergence. When emerging from trees they

may remain around the roost tree or adjacent trees for some time before

venturing away from cover. Their echolocation call is relatively quiet and as a


___________________________________________________________________________________



40

result they are not readily heard on a bat detector, making them prone to under

recording in field surveys.

Brown long-eared bats were the subject of a study in NE Scotland by Entwistle,

Racey and Speakman who radio tracked bats from 6 roosts in 1991 & 1992 in

order to investigate their foraging behaviour and preferences. During this study

bats emerged approximately 55 minutes after dusk and remained active

throughout the night. Individuals used a series of foraging sites to which they

returned regularly, sometimes these were shared with other roost mates. They

foraged exclusively in woodland and around individual trees with a strong

preference for deciduous woodland over coniferous woodland; the authors

suggested that this related to the higher productivity of deciduous woodlands for

Lepidoptera (moths) the principal prey item of this species. Where coniferous

woodland was used, bats remained round the edges not venturing into the centre

of these woodlands.

In this study long-eared bats were observed commuting along hedge lines, tree

and fence lines and along woodland corridors and overgrown banks; males

travelled further than females between roosting sites and foraging areas. Bats

travelled up to 2.8 km maximum distance from roost sites to forage but spent

most of their time within 0.5km of the roost sites and used between 1-9 foraging

sites per night (median 3) with bats returning to the same foraging site up to 5

times per night.

Bats used a limited number of sites in any one location at any one time of the

year and there was high night to night predictability in foraging sites. 77% of sites

were used by the same individual on more than one night. During periods of rain

bats hung up and became inactive but there was no evidence of reduced activity

in lower temperatures (<7C) with bats active at temperatures as low as 3.5C.

The average colony size of the brown long-eared bat in the UK is estimated to be

between 10-20 with occasionally up to 50 (BCT, 2005).

Documents

Bat Surveys of Hurn Forest Dorset - · PDF fileBoth surveyors used a Petterson D240x time expansion detector and Edirol R09 ... These results are shown on Maps 3a & ... 3.3.1 28 June