Kencot Hill Solar Farm, near Kencot, Oxfordshire Ecological … · 2016. 10. 23. · Kencot Hill Solar Farm is situated to the north and east of Kencot Hill Farm, approximately 2km

Windrush Ecology Limited – Howbery Park – Benson Lane – Wallingford OX10 8BA Tel 01491 822681 – Web www.windrushecology.com – Email [email protected] Company Registration No: 7068178 – Place of Registration – 28 High Street, Witney, OX28 6RA

Kencot Hill Solar Farm, near Kencot, Oxfordshire

Ecological Monitoring Report

October 2016

http://www.windrushecology.com/

mailto:[email protected]

Windrush Ecology Limited – Howbery Park – Benson Lane – Wallingford OX10 8BA Tel 01491 822681 – Web www.windrushecology.com – Email [email protected] Company Registration No: 7068178 – Place of Registration – 28 High Street, Witney, OX28 6RA

Job name Kencot Hill Solar Farm, near Kencot, Oxfordshire

Report date 18th October 2016

Report title Ecological Monitoring Report

Reference W1606_rep_Kencot Hill Solar Farm Monitoring_18-10-16

Signed Name Position Date

Prepared by

Edward Bodsworth MA PhD MCIEEM

Director 18/10/16

http://www.windrushecology.com/

mailto:[email protected]

Kencot Hill Solar Farm

W1606_rep_Kencot Hill Solar Farm Monitoring_18-10-16 i

Contents

1 Introduction ............................................................................................................. 1 1.1 Background ...................................................................................................... 1 1.2 Aims of Study ................................................................................................... 1

2 Methodology ............................................................................................................ 2 2.1 Skylark Survey .................................................................................................. 2

2.1.1 Skylark Surveys 2015............................................................................ 3 2.1.2 Skylark Surveys 2016............................................................................ 3

2.2 Butterfly Survey ................................................................................................ 4 2.2.1 Butterfly Surveys 2015 .......................................................................... 4 2.2.2 Butterfly Surveys 2016 .......................................................................... 5

2.3 Botanical Survey ............................................................................................... 5 2.3.1 Botanical Surveys 2015 ......................................................................... 5 2.3.2 Botanical Survey 2016 .......................................................................... 5

3 Results ..................................................................................................................... 6 3.1 Skylarks ............................................................................................................ 6

3.1.1 Survey Results 2015 ............................................................................. 6 3.1.2 Survey Results 2016 ............................................................................. 9

3.2 Butterflies ....................................................................................................... 14 3.2.1 Survey Results 2015 ........................................................................... 14 3.2.2 Survey Results 2016 ........................................................................... 14

3.3 Botany ............................................................................................................ 15 3.3.1 Survey Results 2015 ........................................................................... 15 3.3.2 Survey Results 2016 ........................................................................... 18

4 Discussion ............................................................................................................. 21 4.1 Skylarks .......................................................................................................... 21

4.1.1 Skylark Surveys 2015.......................................................................... 21 4.1.2 Skylark Surveys 2016.......................................................................... 22

4.2 Butterflies ....................................................................................................... 22 4.2.1 Butterfly Surveys 2015 ........................................................................ 22 4.2.2 Butterfly Surveys 2016 ........................................................................ 23

4.3 Botany ............................................................................................................ 24 4.3.1 Botanical Surveys 2015 ....................................................................... 24 4.3.2 Botanical Surveys 2016 ....................................................................... 24

5 Summary ................................................................................................................ 25 5.1.1 Summary 2015 .................................................................................... 25 5.1.2 Summary 2016 .................................................................................... 25

6 References ............................................................................................................. 26

7 Appendix 1. Results of the 2015 Skylark Survey ................................................ 27

8 Appendix 2. Results of the 2016 Skylark Survey ................................................ 28

9 Appendix 3. Butterfly Transect Routes Transect Route 2012 ............................ 29

10 Appendix 4. Butterfly Transect Route 2015/2016 ................................................ 30

11 Appendix 5. Recommendations for Grassland Management ............................. 31

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1 Introduction

1.1 Background

Kencot Hill Solar Farm is situated to the north and east of Kencot Hill Farm, approximately 2km to the south-west of the village of Shilton in West Oxfordshire. The approximate Ordnance Survey grid reference for the centre of the site is SP 247 071. The site comprises an area of grassland which formed part of the former RAF Broadwell Airfield (also known as Shilton Airfield), which was used during World War II. Part of the site forms the Shilton Airfield Local Wildlife Site, a non-statutory site of nature conservation importance on account of the grassland flora that it supports. An extended Phase 1 Habitat Survey of the site was undertaken in March 2012 by Windrush Ecology Ltd with subsequent reptile, skylark, butterfly and botanical surveys undertaken between April & June 2012. For full details of the previous study please refer to Windrush Ecology Ltd, 2012. Proposed Solar Farm at Kencot Hill Farm, Oxfordshire. Protected Species Survey Report. The study provided baseline information on the ecology of the site in order to inform the planning decision. On granting planning consent, conditions for ecological monitoring were stipulated to include botany, skylarks and butterflies. Of particular interest was the response of breeding skylarks to the presence of solar panels, and whether breeding pairs were likely to abandon the site. In addition, it was not known how the sensitive botany of the grassland habitats would react to the disturbance during installation and the presence of the panels to create light, shade, dry and wet areas. Permission was granted for the installation of a solar farm and works were undertaken to install the panels and other equipment during the autumn and winter 2014 and early spring 2015. The site is currently in use as a solar farm and the monitoring surveys were undertaken from April to July 2015, approximately 6 months after the completion of the installation works. The monitoring undertaken in 2015 therefore presents a snap-shot of the site very soon after development was complete. Monitoring was also undertaken in 2016, to include skylark surveys, butterfly transects and a botanical survey. The aim of the botanical survey in 2016 was to compare areas of grassland in shade under the panel arrays to areas in full sun.

1.2 Aims of Study

The aims of this study are to undertake monitoring surveys at Kencot Hill Solar Farm with regard to botany, skylarks and butterflies following the installation of the solar panel arrays. 2015 was the first year since the creation of the solar farm and data gathered during this study will form the baseline for future monitoring. 2016 is the second year of monitoring, and the aims of the monitoring have been adapted to try and understand more about skylark use of the site and about the developing flora under the panels and between the panel arrays. Whilst a quantitative comparison between the site before and after the creation of the solar farm is not possible, due to the nature of the data collected in the support of the planning application and the limits to data collection after the panels have been installed, an attempt is made to qualify the changes to botany, skylarks and butterflies before and after the development. In summary, the studies undertaken in 2015 and 2016 aim to:

Provide a discussion as to whether works and panel installation have deterred skylarks from being active within the site and using the site for nesting;

To determine whether skylarks are successfully breeding and nesting within the site;

Assess whether works have resulted in the loss or degradation of botanical richness and species-rich neutral grassland habitats;

To compare areas of grassland under and between the solar panel arrays with regard to their species composition and abundance;

Assess whether works have resulted in the loss or reduction of specific butterfly species, such as the small heath, and whether there has been degradation in the overall butterfly assemblage.

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2 Methodology

2.1 Skylark Survey

For the purposes of this report, the site is divided into three areas (Areas B, C & G; see Figure 1) to allow comparison with the baseline ecological study undertaken in 2012 to inform the planning application for the solar farm. The aims of the skylark surveys were to look for skylarks within the site and the surrounding area and to map the location of singing male birds, in an attempt to prove definitive nesting by the species within the solar farm.

Figure 1. Plan showing the location for the solar farm outlined in red (and separated into Areas B, C & G). The Shilton Airfield LWS is indicated by the blue shaded areas.

Area 20N01/5

Area 20N01/2

Area 20N01/4 Area 20N01/1

Area 20N01/3

Area 20N01/6

B

G

C

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During the breeding season, male skylarks indulge in ‘song flights’ during which they fly rapidly from the ground into the air, singing continuously (Hedenström, 1995). These flights are believed to be mating displays to female birds and each male holds a small territory around his singing area which will eventually become the nesting territory for the male bird and his female partner. For the purposes of this report, the presence of signing male birds is used as an indication of breeding by a pair of skylarks within the local area around the song flight. An attempt was made to locate and observe skylark nests. However, this is very difficult due to the nest being camouflaged and cryptic.

2.1.1 Skylark Surveys 2015

Table 1. Timing and weather conditions during the 2015 skylark surveys.

Date Timing of

survey Temp (oC)

Weather conditions (at start of survey)

15/04/15 10:15-11:40 20 Warm, Dry, Clear (Cloud Cover 0%), Still (Beaufort Scale 0)

01/05/15 10:20-11:50 8 Cool, Dry, Overcast + Sunny Intervals (Cloud Cover 30%), Breezy (Beaufort Scale 3/4)

21/05/15 10:30-11:50 15 Warm, Dry, Clear (Cloud Cover 0%), Light Breeze (Beaufort Scale 2)

2.1.1.1 Behaviour Characterisation Surveys

Three skylark surveys were undertaken in April and May 2015 by Owen Crawshaw BSc GradCIEEM. Please refer to Table 1 for timings and weather conditions of the surveys. The same methodology was adopted as had been used for the skylark surveys undertaken in 2012 (Windrush Ecology Ltd, 2012). Behaviour by skylarks within and immediately beyond the site was recorded such as: aggressive interactions between birds, birds on the ground and individuals carrying food. The surveys particularly focused on recording and mapping the location of any birds engaging in song flight behaviour.

2.1.1.2 Minimum Population Estimate

During each of the surveys an estimated minimum count as to the number of skylarks present within the site was obtained. Given the habit of movement by the birds within the site not every observation was used to inform the final count. A bird was considered a ‘different individual’ if it was observed within a different location of the site during the survey and was not considered to have crossed into a new row of panelling. Birds recorded offsite were not included within the minimum population estimate.


Table 2. Timing and weather conditions during the 2016 skylark surveys. Date Timing of

survey Temp (oC)

Weather conditions (at start of survey)

27/04/16 08:40-11:19 6 Cool, dry, sunny, clear (cloud cover 0%), dry, calm, (Beaufort Scale 1)

25/05/16 08:20-10:25 11 Mild, dry, overcast (cloud cover 100%), light breeze (Beaufort Scale 3)

08/06/16 08:05-10:30 16.5 Warm, dry (rain overnight), muggy, mostly clear (cloud cover 40%), still (Beaufort Scale 0)

21/06/16 05:00-07:00 12 Mild, dry, mostly clear (cloud cover 30%), calm (Beaufort Scale 1)


Three skylark surveys were undertaken between April and June 2016 by Owen Crawshaw BSc GradCIEEM and Robert Spencer BSc. The surveys (27th April, 25th May & 8th June 2016) followed

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the same methodology as the initial surveys in 2012 (pre-development) and those completed as part of the first year of monitoring in 2015 (see Section 2.1).


A population count was conducted to estimate the minimum number of individual birds within the study site. The count used the same methodology and was conducted by the same surveyor as in 2015 (see Section 2.1.1.2). A minimum population count was not completed for the nest search survey of the 8th June 2016.

2.1.2.3 Nest Search Survey

The final survey, which was completed on the 21st June 2016, adopted a different method to the previous surveys and focused on attempting to locate and record skylark nests. A transect was walked around the area of the site identified as having the greatest level of skylark activity (Area G). The survey was undertaken before dawn, when it was assumed that birds would be on the ground, on the nest. Surveyors walked a transect and watched for any skylarks that flew to ground and then proceeded to undertake a careful search of the grassland between and beneath panel arrays for any active or inactive skylark nests. A thermo-imaging camera was used to try and locate adult birds on the ground, and thus locate active nests on the ground. The aim of the survey was to find active or inactive skylark nests. This methodology was adopted due to the difficulty of finding skylark nests on the ground during the daytime. Skylarks nests are almost impossible to see, and adult birds will take measures to direct attention away from the nest rather than staying on the nest. By using thermos-imaging, the hope was that resting birds on the ground could be more easily seen as the warmth of their bodies would be obvious against the cold ground.

2.2 Butterfly Survey

2.2.1 Butterfly Surveys 2015

Butterfly transects were walked through the site during June and July 2015 to look for late spring and summer butterflies and to determine the presence of certain UK Post-2010 Biodiversity Framework (formerly the Biodiversity Action Plan) species. Transect methodology followed that of Pollard and Yates (1993) during which the surveyor walks at a steady pace and records all butterfly observations within an imaginary 5m by 5m quadrat in front of themselves. All butterflies seen flying within the quadrat were recorded. For the butterfly surveys undertaken in 2012, the transect was divided into six compartments over three areas B, C & G (shown in Figure 1) and butterflies for each section were recorded separately to provide some information regarding habitat variability and the distribution of the different species. Due to the installation of the panel arrays, the same transect route could not be walked during 2015, and an alternative, but similar route was planned and followed through the panels, taking in as much as the previous transect as possible. The transects in 2015 were undertaken in areas B & G only (compartments 1, 2 & 6), in order to simplify the route and to overcome problems of access through perimeter fences. The transect routes undertaken in 2012 and 2015 are shown in Appendix 3. Table 3. Timing and weather conditions during the 2015 butterfly surveys

Date Timing of

survey Temperature

(°C) Weather conditions

04/06/15 13:00-14:50 17 Warm, dry, isolated clouds (Cloud Cover 40%), still with an occasional breeze (Beaufort Scale 0-2)

02/07/15 11:48-14:40 19 Warm, dry, overcast (Cloud Cover 100%), gentle breeze (Beaufort Scale 2)

30/07/15 11:00-13:30 18 Warm, dry, sunny (Cloud Cover 20%), gentle breeze (Beaufort Scale 1)

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Butterfly transects were walked through the site during May and June 2016 to look for late spring and summer butterflies and to determine the presence of certain UK Post-2010 Biodiversity Framework (formerly the Biodiversity Action Plan) species. Transect methodology followed that of Pollard and Yates (1993) during which the surveyor walks at a steady pace and records all butterfly observations within an imaginary 5m by 5m quadrat in front of themselves. All butterflies seen flying within the quadrat were recorded. The same methodology was adopted as for the survey in 2015. The transect routes undertaken in 2012, 2015 and 2016 are shown in Appendix 3. 2016 was a particularly bad year for butterfly numbers throughout the UK. It is hypothesised that this may have been the result of a mild winter followed by a relatively cold spring. As can be seen from the results, butterfly numbers in 2016 were lower than 2015 for all species. Although a third butterfly survey was scheduled for 2016, bad weather on the scheduled survey dates, in addition to the overall low numbers of butterflies, meant that a third butterfly survey was not undertaken in this year. Table 4. Timing and weather conditions during the 2016 butterfly surveys

Date Timing of survey Temperature

(°C) Weather conditions

26/05/16 11:00-14:00 17 Warm, dry, relatively cloudy (Cloud Cover 80%), still with an occasional breeze (Beaufort Scale 1)

21/06/16 11:00-14:00 19 Warm, dry, sunny (Cloud Cover 10%), still (Beaufort Scale 0)

2.3 Botanical Survey

2.3.1 Botanical Surveys 2015

Botanical surveys were undertaken in June and July 2015 by Tracy Gray BSc GradCIEEM. A walkover of the site was conducted and a list of plant species was collated for the grassland flora within Areas B & G, along the routes of the butterfly transects. Each species was assigned an abundance level according to the DAFOR scale: D = Dominant; A = Abundant, F = Frequent, O = Occasional, R = Rare. The survey was timed to coincide with the flowering periods of certain species of orchid, such as the pyramidal and bee orchids, which are known to occur within the site. The initial survey was undertaken prior to the installation of the panel arrays in order to inform an ecological appraisal of the site in order to support a planning application for the solar farm. The results of this initial botanical survey establish a ‘baseline’ of the species present within the grassland habitats and their relative abundance. The survey carried out in 2015 aims to assess changes in species composition within the grassland in order to understand of the impacts on unimproved grassland (Lowland Meadow) habitat. It should be noted that installation of the panels resulted in ground disturbance throughout the site and thus, changes in diversity and abundance are expected. It is not considered possible or appropriate at this stage to provide a quantitative analysis of change, given the levels of the disturbance. The current study therefore aims to confirm whether the grassland still qualifies as unimproved grassland (Lowland Meadow) habitat and whether overall the species assemblage is similar to that which was present prior to the works to install the panels. The survey results from 2012 for Areas B & G (northern section of the solar farm) have been combined in order to compare the species composition and species richness between years in the northern area of the solar farm. The results have been combined due to the fact that Areas B & G now form a homogenous habitat with no clear difference in habitat type.

2.3.2 Botanical Survey 2016

A botanical survey was undertaken in Area G on 28th June 2016. The aim of the survey was to compare areas of grassland under the panel arrays with areas of grassland between the panel arrays; comparing sunny and shaded areas. The following methodology was adopted.

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Ten quadrats were placed at random within ten locations under the panels and ten locations between the panels. The randomisation of the quadrats was achieved by numbering ten of the panel arrays 1 to 10 and generating random numbers from one to ten. The first number indicated which panel array the quadrat was to be placed and the second number indicated the distance (in metres) the quadrat was placed along the panel row. For each panel selected at random, a location under the panel and between the panels was surveyed. In this manner, ten quadrat locations were found in the shade and ten in the sun. For each quadrat, the abundance of each plant species within the quadrat was estimated on a scale of 1 to 10. The abundance of each species was totalled for all ten of the quadrats, and divided by ten to give an Index of abundance (from 0.1 to 10). For example, let us say that pyramidal orchid was recorded as shown below. Table 5. An example of the botanical abundance index calculation

Quadrat number Abundance 1 to 10

1 0

2 0

3 0

4 0

5 0

6 3

7 0

8 0

9 4

10 0

Total 7

Index of Abundance (total/10) 0.7

The botanical survey was supplemented by a second field visit on 25th August 2016 which looked for late-flowering species which may have been missed during the survey on 28th June.

3 Results

3.1 Skylarks

3.1.1 Survey Results 2015

3.1.1.1 Behavioural Characterisation Survey

Skylarks are still present within the site and were observed during all three of the surveys, including signing males and female birds. During all three surveys, skylarks were observed perching on the solar panels, as well as flying between the arrays. No nests were found, although behaviour indicates that skylarks were attempting to nest within the site. Territorial song flights from male birds were recorded on each visit, with a maximum count of 8 singing males recorded during the survey of 15th April 2015. The majority of the territorial singing behaviour was concentrated within Area G. Only a single bird was observed engaging in song flight behaviour within Area C on one occasion, whereas no singing skylarks were recorded within Area B during any of the surveys. During all three surveys, individual skylarks were also observed on the ground beneath solar panels. A pair of birds was documented moving from the panels to the ground within Area G on 15th April 2015. This behaviour was also recorded on 2 separate occasions during the survey of 1st May 2015, with similar behaviour seen again on 21st May 2015 involving a single bird within Area C. Please refer to Appendix 1 for further information regarding the location of the skylark observations.

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The results of the 2015 minimum population estimate are presented in Table 6. Table 6. An estimate as to the minimum number of individual skylarks present within Kencot Solar Farm during the 2015 skylark surveys.

Date Minimum number of skylarks present

15/04/15 12

01/05/15 9

21/05/15 7

Mean = 9.3

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Table 7. Results of the 2015 skylark surveys undertaken at Kencot Solar Farm (please refer to Appendix 1).

Date Observation Location Notes

Skylark(s) resting on panels

Area G 1 bird

15/04/15

Area G (North of Plot 3) 3 birds (2 on ground amongst panels)

Area G (East of Plot 2) 1 bird

Area C (North of Plot 1) 2 birds (possible male + female)

Skylark(s) territorial singing

Area G 1 bird

Area G (South-west of Plot 3) 4 birds

Area G (North-east of Plot 2) 1 bird

Area G 1 bird

East of Area G (offsite) 1 bird

01/05/15

Skylark(s) on ground beneath panels Area G (South-west of Plot 3) 1 bird

Area G 1 bird


Area G (North of Plot 3) 1 bird

Area B (North-east of Plot 2) 2 birds

Area C 2 birds

Skylark(s) territorial singing

Area G 1 bird

Area G 1 bird (rising then landing)

Area G 1 bird (rising then landing)

Area G (South-east of Plot 2) 1 bird

Area C (North of Plot 1) 1 bird


21/05/15

Skylark(s) territorial singing East of Area G (offsite) 1 bird


Area G 2 birds

Area G 2 birds

Area G 2 birds

Area G 1 bird (moved east from offsite)

Area G (south of Plot 3) 1 bird

Area C (west of Plot 1) 1 bird on ground and on panels

Area C (north of Plot 1)

1 bird

Mr. T. Czapski Kencot Hill Solar Farm

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Skylarks were recorded as still being present within the solar farm during the 2016 survey period and were recorded on all four visits to the site. Skylarks were recorded in both Area G and Area C but were not recorded within Area B. A variety of skylark behaviours were witnessed by the surveyors during the surveys. Territorial song flights by male birds were observed during each of the surveys. A maximum count of 7 displaying birds were recorded on 8th June 2016. 69% of the display flights recorded within the site were observed within Area G, while the remaining 31% were seen in Area C. No territorial song flights by skylarks were recorded within Area B during the 2016 survey period. As well as the typical song flights of the male birds, territorial interactions between birds was also recorded during the surveys. This behaviour was recorded during each survey and involved 3-4 individuals engaging in aggressive chasing behaviour. The most regularly recorded behaviour by skylarks during the surveys, was observation of the birds resting on panel arrays. This resting behaviour accounted for 53% of all observations across the behaviour characterisation surveys. Notably during the final survey (8th June 2016) a single bird was seen resting on a panel with invertebrate prey (see Photograph 1), the bird was watched for several minutes during which time it did not consume the prey. The bird then flew off and could not be relocated by the surveyors. 79% of observations regarding birds resting on solar panels occurred within Area G, with the remaining 21% attributed to Area C. No skylarks were seen resting on panels within Area B.

Photograph 1. A skylark resting on a solar array panel within Kencot Solar Farm with invertebrate prey. Photo by Owen Crawshaw 08/06/16.

During all three behaviour characterisation surveys, skylarks were recorded on the ground between or beneath panel arrays. The cryptic nature of the birds and the sward height of the grassland (Photograph 2) meant observations were only recorded when a skylark was seen to fly to ground, or a bird was flushed up from the ground. During the survey of the 25th May 2016 the behaviour was exclusively recorded from pairs of interacting birds that were seen to either fly down or up to/from the ground respectively. The behaviour was also exhibited by individual birds during other surveys.


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Photograph 2. A skylark on the ground between panel arrays at Kencot Solar Farm. Photo by Owen Crawshaw 27/04/16.

Full details of 2016 behavioural classification surveys are presented in Table 9. Please refer to Appendix 2 for a map of recognised skylark territories recorded during the 2016 monitoring programme.


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The results of the 2016 minimum population estimate are presented in Table 8. Table 8. An estimate as to the minimum number of individual skylarks present within Kencot Solar Farm during the 2015 skylark surveys.

3.1.2.3 Nest Search Survey

No confirmed active or inactive skylark nests were recorded during the nest search survey of 21st June 2016. A single bowl-shaped depression (Photograph 3) was recorded beneath a row of panels within Area G. No evidence of nesting by skylarks was recorded within the bowl.

Picture 3. A bowl-shaped depression within the grass (a possible skylark nest), recorded beneath a solar panel array, at Kencot Solar Farm. Photo by Owen Crawshaw 21/06/16

Date Minimum number of skylarks present

27/04/16 11

25/05/16 14

08/06/16 14

Mean = 13

Mr T. Czapski Kencot Solar Farm

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Table 9. Results of the 2016 skylark surveys (behavioural classification surveys) undertaken at Kencot Solar Farm.



Area G 1 bird Area G 1 bird Area G 2 birds Area G 2 birds Area G (South-east of Plot 2) 1 bird 27/04/16


Area G (South west of Plot 2) 1 bird

Area G (East of Plot 3) 2 birds


Area C (North of Plot 1) 1 bird

Skylark(s) on ground between/beneath panels

Area G 1 bird (descended from display flight, landed between panels and

remained within an area of taller grass - see photo

Area G 1 bird flushed from underneath solar panel

Skylark(s); territorial singing and display flight

Area G 1 bird rising then landing on ground between panels



Area C 1 bird

East of Area G (offsite) 3 birds displaying, singing and aggressive chasing behaviour



Area G 1 bird Area G 1 bird 25/05/16

Area G (Adjacent to Plot 2) 3 birds briefly, 2 individuals remained longer than other

Area C 2 birds

Area C (North-west of Plot 1) 2 birds

Area G 2 birds (possible pair) interacting

Area G 2 birds

Area C 2 birds


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Area G 4 birds engaging in aggressive chasing behaviour and display

flight

Area G 1 bird

Area G (East of Plot 2) 1 bird

Area C 1 bird


Area G 1 bird with food

Area G 1 bird Area G 1 bird 08/06/16

Area G 2 birds

Area G) 1 bird

Area G (Adjacent to Plot 2) 2 birds

Area G (South of Plot 2) 1 bird

Area C 2 birds

Area C 1 bird

Skylark(s) on ground between/beneath panels

Area G 1 bird

Area G 1 bird

Area G 2 birds


Area G (South-east corner) 1 bird

Area G (South-west of Plot 2) 1 bird

Area G (North-west of Plot 2) Territorial interaction between 3 birds

Area C 1 bird

Area C 1 bird


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3.2 Butterflies


The surveys undertaken in 2015 recorded small heath Coenonympha pamphilus within the site, which is a priority species listed within the UK Post-2010 Biodiversity Framework and a species that was previously recorded in 2012. Dingy skipper Erynnis tages and green hairstreak Callophrys rubi were not recorded in 2015. Table 10. Results of butterfly surveys in 2015 Date Species Latin Name Numbers seen during

transect

01/06/15 Brimstone Brown argus Common blue Green veined-white Small heath Speckled wood

Gonepteryx rhamni Aricia agestis Polyommatus icarus Pieris napi Coenonympha pamphilus Pararge aegeria

1 4 9 1 3 6

12/07/15 Common blue Essex skipper Large skipper Marbled white Meadow brown Ringlet Small heath Small tortoiseshell Speckled wood

Polyommatus icarus Thymelicus lineola Ochlodes venata Melanargia galathea Maniola jurtina Aphantopus hyperantus Coenonympha pamphilus Nymphalis urticae Pararge aegeria

8 6 11 48 127 59 12 22 3

30/07/15 Common blue Essex skipper Large skipper Marbled white Meadow brown Ringlet Small heath Small tortoiseshell Speckled wood Small white Brown argus

Polyommatus icarus Thymelicus lineola Ochlodes venata Melanargia galathea Maniola jurtina Aphantopus hyperantus Coenonympha pamphilus Nymphalis urticae Pararge aegeria Pieris rapae Aricia agestis

2 1 3 32 88 54 10 7 1 3 1


Table 11. Results of butterfly surveys in 2016 Date Species Latin Name Numbers seen during

transect

26/05/16 Common blue Essex skipper Large skipper Marbled white Meadow brown Ringlet Small heath Small tortoiseshell Speckled wood Green-veined white

Polyommatus icarus Thymelicus lineola Ochlodes venata Melanargia galathea Maniola jurtina Aphantopus hyperantus Coenonympha pamphilus Nymphalis urticae Pararge aegeria Pieris napi

7 1 2 6 23 5 8 11 1 2

21/06/16 Common blue Essex skipper Large skipper

Polyommatus icarus Thymelicus lineola Ochlodes venata

11 4 3


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Date Species Latin Name Numbers seen during transect

Marbled white Meadow brown Ringlet Small heath Small tortoiseshell Speckled wood

Melanargia galathea Maniola jurtina Aphantopus hyperantus Coenonympha pamphilus Nymphalis urticae Pararge aegeria

8 20 6 11 3 2

As discussed previously, numbers of butterflies recorded in 2016 throughout the UK are considered to be low. The reasons for this are unknown, but there are some hypotheses that mild weather during the winter of 2015/2016 may have resulted in low survival of butterfly larvae and pupae over the winter period. Data gathered from 2016 indicates lower numbers of butterflies overall at the solar farm, although the assemblage appears to be largely unchanged.

3.3 Botany


Grass and herbaceous species noted within the unimproved grassland habitat of the northern section of the site (Areas B & G) can be found in Tables 12 & 13, providing data on the 2012 and 2015 surveys respectively; the tables also include the relative abundance (DAFOR scale). Table 12. Grass and herbaceous species recorded within the site during 2012, including assigned an abundance level according to the DAFOR scale.

Grasses

Common Name Latin Name DAFOR scale Subsequently recorded (Y/N)

Cock’s foot Dactylis glomerata A Y

Creeping bent Agrostis stolonifera A N

Crested dog’s tail Cynosurus cristatus A Y

False oat grass Arrhenatherum elatius A Y

Fescues Festuca spp. O Y

Meadow brome Bromus commutatus O N

Meadow grasses Poa spp. A Y

Timothy Phleum pratense O Y

Tor grass Brachypodium rupestre F N

Yellow oat grass Trisetum flavescens A N

Yorkshire fog Holcus lanatus A Y

Herbs

Common Name Latin Name DAFOR scale Subsequently recorded (Y/N)

Bee orchid Ophrys apifera R N

Black Medick Medicago lupulina O Y

Bladder campion Silene vulgaris O Y

Bramble Rubus fruticosus F Y

Broad-leaved dock Rumex obtusifolius R Y

Common birds-foot-trefoil Lotus corniculatus A Y

Common centaury Centaurium erythraea F Y

Common mouse-ear Cerastium fontanum A Y

Cowslip Primula veris O Y

Creeping buttercup Ranunculus repens O Y

Creeping thistle Cirsium arvense R Y

Cut-leaved cranesbill Geranium dissectum O Y

Daisy Bellis perennis O Y

Dandelion Taraxacum officinale A Y

Dog violet Viola riviniana O N

Dyer’s greenweed Genista tinctoria F Y

Eyebright Euphrasia sp. O N

Fairy flax Linum catharticum A Y


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Forget-me-not Myosotis sp. O Y

Germander speedwell Veronica chamaedrys O Y

Grass vetchling Lathyrus nissolia F N

Greater burdock Arctium lappa O Y

Ground ivy Glechoma hederacea O Y

Horseradish Armoracia rusticana O Y

Hounds tongue Cynoglossum officinale O N

Lady’s bedstraw Galium verum A Y

Lesser stitchwort Stellaria graminea O Y

Marjoram Origanum vulgare A Y

Meadow vetchling Lathyrus pratensis O N

Musk mallow Malva moschata O N

Ox-eye daisy Leucanthemum vulgare A Y

Perforated St. John’s wort Hypericum perforatum F Y

Pyramidal orchid Anacamptis pyramidalis R Y

Ragwort Senecio jacobaea R Y

Ribwort plantain Plantago lanceolata A Y

Salad burnet Sanguisorba minor O N

Self-heal Prunella vulgaris R Y

Smooth tare Vicia tetrasperma A Y

Spear thistle Cirsium vulgare R Y

Stinging nettle Urtica dioica O Y

Teasel Dipsacus pilosus R Y

Traveller’s joy Clematis vitalba O Y

White clover Trifolium repens A Y

Wild basil Clinopodium vulgare F N

Wild parsnip Pastinaca sativa A Y

Yellow rattle Rhinanthus minor A N

Table 13. Grass and herbaceous species recorded within the site during 2015, including assigned an abundance level according to the DAFOR scale.

Grasses

Common Name Latin Name DAFOR scale Previously recorded (Y/N)

Cock’s foot Dactylis glomerata O Y

Crested dog’s tail Cynosurus cristatus O Y

False oat grass Arrhenatherum elatius O Y

Fescues Festuca spp. O Y

Meadow grasses Poa spp. O Y

Sedge Carex sp. O N

Soft brome Bromus hordeaceus O N

Timothy Phleum pratense O Y

Yorkshire fog Holcus lanatus O Y

Herbs

Common Name Latin Name DAFOR scale Previously Recorded (Y/N)

Agrimony Agrimonia eupatoria O N

Black horehound Ballota nigra R N

Black knapweed Centaurea nigra O N

Black medick Medicago lupulina F Y

Blackthorn saplings Prunus spinosa F N

Bladder campion Silene vulgaris F Y

Bloody cranesbill Geranium sanguineum R N

Blue fleabane Erigeron acer R N

Bramble Rubus fruticosus F Y

Bristly ox-tongue Picris echioides O N

Broad-leaved dock Rumex obtusifolius F Y

Bugle Ajuga reptans R N

Catsear Hypochaeris radicata F N


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Cleavers Galium aparine F N

Common bird’s-foot-trefoil Lotus corniculatus A Y

Common centaury Centaurium erythraea F Y

Common comfrey Symphytum officinale F N

Common fumitory Fumaria officinalis R N

Common mouse-ear Cerastium fontanum F Y

Common toadflax Linaria vulgaris O N

Common vetch Vicia sativa O N

Cowslip Primula veris A Y

Creeping buttercup Ranunculus repens F Y

Creeping cinquefoil Potentilla reptans F N

Creeping thistle Cirsium arvense A Y

Curled dock Rumex crispus O N

Cut-leaved cranesbill Geranium dissectum O Y

Daisy Bellis perennis O Y

Dandelion Taraxacum officinale O Y

Dog rose Rosa canina R N

Dyer’s greenweed Genista tinctoria A Y

Elder saplings Sambucus nigra O N

Fairy flax Linum catharticum O Y

Field pansy Viola arvensis R N

Field penny-cress Thlaspi arvense A N

Field scabious Knautia arvensis O N

Field speedwell Veronica persica O N

Forget-me-not Myosotis sp. O Y

Fox and cubs Pilosella aurantiaca R N

Garlic mustard Alliaria petiolata F N

Germander speedwell Veronica chamaedrys O Y

Goatsbeard Tragopogon pratensis O N

Golden melilot Melilotus altissima O N

Goosefoot Chenopodium sp. O N

Greater burdock Arctium lappa A Y

Ground ivy Glechoma hederacea A Y

Hawthorn saplings Crataegus monogyna O N

Hedge bedstraw Galium mollugo F N

Hogweed Heracleum sphondylium O N

Horseradish Armoracia rusticana R Y

Lady’s bedstraw Galium verum F Y

Lesser stitchwort Stellaria graminea O Y

Marjoram Origanum vulgare F Y

Meadow buttercup Ranunculus acris O N

Mignonette Reseda lutea R N

Opium poppy Papaver somniferum F N

Ox-eye daisy Leucanthemum vulgare A Y

Perforate St. John’s Wort Hypericum perforatum F Y

Poppy Papaver sp. R N

Pyramidal orchid Anacamptis pyramidalis A Y

Ragwort Senecio jacobaea F Y

Red campion Silene dioica R N

Red clover Trifolium pratense F N

Red dead-nettle Lamium purpureum O N

Restharrow Onions repens O N

Ribwort plantain Plantago lanceolata F Y

Scarlet pimpernel Anagallis arvensis R N

Self-heal Prunella vulgaris F Y

Smooth tare Vicia tetrasperma O Y

Sow thistle Sonchus sp. F Y

Spear thistle Cirsium vulgare O Y

Spotted medick Medicago arabica F N

Stinging nettle Urtica dioica O Y


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Teasel Dipsacus fullonum A Y

Traveller’s joy Clematis vitalba F Y

Tufted vetch Vicia cracca O N

Wall speedwell Veronica arvensis R N

Weld Reseda luteola O N

White campion Silene latifolia R N

White clover Trifolium repens F Y

White dead-nettle Lamium album O N

Wild carrot Daucus carota O N

Wild parsnip Pastinaca sativa O Y

Wood avens Geum urbanum O N

Yarrow Achillea millefolium F N

Yellow loosestrife Lysimachia vulgaris R N

Yellow-wort Blackstonia perfoliata O N


The assemblage and abundance of plant species under the panels (in the shade) was noticeably different to the assemblage and abundance of plant species between the panels (in the sun). In the shade (see Table 14), the sward was dominated by tall grasses, with creeping buttercup and creeping cinquefoil being the commonest herbs. Grasses were dominant, and other species were found in relatively low abundance. Table 14. Species list and index of abundance for plants under the panel arrays, in the shade.

Species (Shade) Index of Abundance

Yorkshire fog Holcus lanatus 5.6

Creeping buttercup Ranunculus repens 4.2

False oat-grass Arrhenatherum elatius 4.0

Cock’s-foot Dactylis glomerata 3.8

Creeping cinquefoil Potentilla reptans 2.2

Field bindweed Convolvulus arvensis 1.9

Stinging nettle Urtica dioica 1.0

Timothy grass Phleum pratense 0.6

Dog rose Rosa canina 0.5

Hawthorn Crataegus monogyna 0.5

Creeping bent Agrostis stolonifera 0.5

Bramble Rubus fruticosus 0.4

Red clover Trifolium pratense 0.4

Broad-leaved willowherb Epilobium montanum 0.4

Blackthorn Prunus spinosa 0.4

Pyramidal orchid Anacamptis pyramidalis 0.4

Creeping thistle Cirsium arvense 0.4

Wild basil Clinopodium vulgare 0.4

Red dead-nettle Lamium purpureum 0.2

Smooth sow thistle Sonchus oleraceus 0.2

Cow parsley Anthriscus sylvestris 0.2

Bladder campion Silene vulgaris 0.1

Meadow crane’s-bill Geranium pratense 0.1

Common ragwort Senecio jacobaea 0.1

More plant species were found between the panel arrays, and the habitat was less dominated by just a few species. Although grasses were still the most abundant of species within the sunny areas, herbs were more diverse. Table 15. Species list and index of abundance for plants between the panel arrays, in the sun.

Species (Sun) Index of Abundance

Meadow grasses Poa species 4.2

Yorkshire fog Holcus lanatus 3.7


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Timothy grass Phleum pratense 3.2

Creeping buttercup Ranunculus repens 3.0

Selfheal Prunella vulgaris 2.6

Creeping cinquefoil Potentilla reptans 1.9

White clover Trifolium repens 1.8

Tall melilot Melilotus altissimus 1.7

Bird’s-foot trefoil Lotus corniculatus 1.7

Oxeye daisy Leucanthemum vulgare 1.4

Perforate St John’s wort Hypericum perforatum 0.9

Red clover Trifolium pratense 0.7

Broad-leaved willowherb Epilobium montanum 0.6

Wild basil Clinopodium vulgare 0.5

Red bartsia Odontites vulgaris 0.5

Pyramidal orchid Anacamptis pyramidalis 0.5

False oat-grass Arrhenatherum elatius 0.4

Dandelion Taraxacum officinale 0.4

Field bindweed Convolvulus arvensis 0.4

Black medick Medicago lupulina 0.4

Teasel Dipsacus fullonum 0.3

Common ragwort Senecio jacobaea 0.3

Greater plantain Plantago major 0.3

Fairy flax Linum catharticum 0.3

Common centaury Centaurium erythraea 0.3

Common vetch Vicia sativa 0.2

Agrimony Agrimonia eupatoria 0.2

Cowslip Primula veris 0.2

Sheep’s fescue Festuca ovina 0.2

Lady’s bedstraw Galium verum 0.2

Wild parsnip Pastinaca sativa 0.2

Blue fleabane Erigeron acris 0.1

Ribwort plantain Plantago lanceolata 0.1

Field scabious Knautia arvensis 0.1

Black knapweed Centaurea nigra 0.1

Other plant species that were not recorded within the quadrats, but that were noted elsewhere in the sward in 2016 include:

Meadow buttercup Geranium pratense

Weld Reseda luteola

Toadflax Linaria vulgaris

Smooth tare Vicia tetrasperma

Ground ivy Glechoma hederacea

Scarlet pimpernel Anagallis arvensis

Greater knapweed Centaurea scabiosa

Tor grass Brachypodium pinnatum

Yarrow Achillea millefolium

Tansy Tanacetum vulgare

White campion Silene alba

Red campion Silene dioica

Spear thistle Cirsium vulgare

Knotgrass Polygonum aviculare

Prickly oxtongue Picris echioides

Rough hawk’s-beard Crepis biennis

Field speedwell Veronica arvensis

Clematis Clematis vitalba

Bittersweet Solanum dulcamara

Round leaved fluellen Kickxia spuria


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Cut-leaved crane’s-bill Geranium dissectum

Goat’s rue Galega officinalis

Forget-me-not Myosotis species

Common mallow Malva sylvestris

Nipplewort Lapsana communis

Broad-leaved dock Rumex obtusifolius

Broomrape Orobanche species

Traveller’s joy Clematis vitabla

Poppy Papaver rhoeas

Opium poppy Papaver somniferum

Grass vetchling Lathyrus nissolia

Marjoram Origanum vulgare

Hogweed Heracleum sphondylium

Comfrey Symphytum officinale

Herb Robert Geranium robertianum

Garlic mustard Allaria petiolata

Cleavers Galium aparine

Daisy Bellis perennis

Fox & cubs Pilosella aurantiaca

Hedge woundwort Stachys sylvatica

Germander speedwell Veronica chamaedrys

Hedge bedstraw Galium mollugo

Greater burdock Arctium lappa

Black horehound Ballota nigra

Great mullein Verbascum thapsus

Sorrel Rumex acetosa

Dyer’s greenweed Genista tinctoria

Thyme-leaved speedwell Veronica serpyllifolia

Tufted vetch Vicia cracca

Colt’s-foot Tussilago farfara

Goat’s-beard Tragopogon pratensis

Common spotted orchid

Yellow rattle


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4 Discussion

4.1 Skylarks

Skylarks breed from April to early August and the choice of nesting site is influenced by the height and density of the sward/crop, with an ideal vegetation height being 20-50cm (roughly the height of the sward within the site prior to development). Skylarks generally hold the same territory throughout the season, and stop breeding activity when the vegetation becomes unsuitable for nesting. Although the highest densities of nests are found in set-aside and spring-sown cereals, grassland and pasture are also be used. The nest is a hollow on the ground, lined with leaves, grasses and hair. The increase in intensive farming practices has lead to a decline in the distribution and abundance of the species and it is now listed as a priority for conservation action within the UK Biodiversity Action Plan, as well as being covered under the duties of Section 41 of the NERC Act 2006. It is also listed on the Red List of Birds of Conservation Concern (BoCC). There are several questions that arise when discussing skylarks and solar farms:

Are skylarks deterred from breeding due to the presence of solar panels within an operational solar farm?

Will skylarks adopt nest sites, within suitable habitat, between photo-voltaic panel arrays?

How are levels of skylark activity affected by the presence of solar panels?

Can impacts on the species be successfully mitigated or compensated?


The results of the monitoring surveys in 2015 confirm that skylarks are still active and present within Kencot Hill Solar Farm. Singing males are present, as well as female birds, and the indication is that approximately five male skylark territories are being held/competed for within Area G, one in Area C and an additional territory located offsite; immediately beyond the eastern boundary of Area G. While the recording of territorial song flights by male birds cannot categorically confirm breeding by skylarks, it is considered to serve as a strong indicator towards the presence of a breeding pair. Thus, it appears that the installation of the solar panels has not deterred skylarks from being present, nor has it deterred male birds from holding territories within the solar panel arrays and attempting to breed within the solar farm. When comparing the 2015 survey results to those of the 2012, some general trends were observed. During both studies, no territorial song flights were observed within Area B, the north-western section of the survey site, which would indicate an absence of breeding skylarks from this area. In addition, 2015 saw a greater number of territories held within Area G (5 territories), compared to the study undertaken in 2012 (2 territories). In contrast to this, fewer territories were recorded within Area C during 2015 (1 territory), against 2012 (2 territories). It appears that the works to install the solar farm may have resulted in some shifting of territories and behaviour, but overall the presence and number of skylarks appears to be relatively unchanged. Other types of behaviour recorded in 2015 included skylarks resting on and moving between solar panels. The fact that skylarks will readily use the panels for perching is strong evidence to support the idea that the birds are not deterred by the presence of panels, and so not perceive the panels as a threat. Furthermore, song flight displays above the solar panels as well as resting on the ground between the panels appears to indicate normal behaviour by the species and suggests that the panels are not altering the behaviour of the birds. The location of the skylark territories recorded in 2015 (Appendix 1) does not appear to show a distinct correlation with the positioning of the ‘skylark plots’ amongst the panels (three 15m by 15m areas of grassland were retained within the panel arrays as a mitigation measure). Competing males


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were not observed above the plots and nesting pairs were not observed within the plots. Skylark activity appeared to be spread through the solar farm and there was no indication of activity specifically centred around the plots. It appears as though skylarks are undeterred by the panels and that activity is spread through the panel arrays, with birds using grassland strips between the panels rather than centring their activity over the ‘skylark plots’.


The results of the surveys undertaken in 2016 confirm that skylarks have remained present and active within Kencot Hill Solar Farm since 2015. Comparing the results of the 2015 and 2016 minimum population estimates it can be seen that there has been an average increase of 3.7 birds in terms of the minimum number of individuals using the site between 2015 and 2016. The number of ‘breeding territories’ has remained the same (5 territories), although there has been a small shift in the distribution of the territories within the solar farm. 2016 has seen the loss of 1 breeding territory from Area G but has gained an additional breeding territory within Area C. Interestingly, 2 territories were recorded within Area C in 2012, prior to the installation of the solar farm. Observations of skylark behaviour during the 2016 monitoring programme provide additional evidence to support the hypothesis that skylarks are actively breeding within Kencot Solar Farm. The presence of an individual bird carrying (but not consuming) invertebrate prey, as recorded on the 8th June 2016, would strongly suggest the presence of precocial (dependant) chicks within the site. The species is a recognised ground-nesting bird and during the surveys individuals were observed and photographed interacting within the ground beneath and between panel arrays. The finding of a bowl-shaped grass depression within the solar farm during the nest search survey of 8th June is not considered to provide conclusive evidence of nesting by skylarks. While the described feature was considered to be of a suitable size and shape for a skylark nest, the interior of the feature lacked the weaving of grass typical of this species. In addition, no eggs, shell fragments, feathers or and faecal sacs were observed within or immediately beyond the rim of the bowl. Having said this, removal of such nesting evidence is observed in many bird species as an attempt to reduce the likelihood of nest predation. The described depression is considered to be one of the following, either: an early/abandoned nesting attempt by skylarks, a roost used by an adult skylark or a small mammal nest e.g. voles or shrews.

4.2 Butterflies


In 2012, UK Post-2010 Biodiversity Framework priority species that were found within the site were small heath Coenonympha pamphilus and dingy skipper Erynnis tages. Other species noted within the site in 2012 included the green hairstreak Callophrys rubi, meadow brown Maniola jurtina, ringlet Aphantopus hyperantus, small skipper Thymelicus sylvestris, common blue Polyommatus icarus and marbled white Melanargia galathea. In 2015, small heath butterflies are still present but no dingy skippers were recorded. In 2015, the peak count of small heath was 12 butterflies (over the whole transect), with 19 being recorded in 2012 over transect compartments 1, 2 & 6 (which cover a similar area to the transect on 2015). This is a similar number and indicates that the abundance of this species has not changed significantly following the works to install the solar farm. The species is still present and appears to occur in similar numbers as recorded in 2012. Butterfly numbers naturally fluctuate due to weather, preceding weather, winter weather, timing of surveys and several other factors. The small heath is associated with dry, open grasslands with fine grasses within the sward, especially in well-drained locations such as downland, heathland and coastal dunes. Its larval foodplants are widespread and include a number of common grasses such as fescues, meadow-grasses and bents. Small heath butterflies are most abundant on grassland that is short and sparse and contains a mixture of their larval food plants and a variety of nectar sources that are available during their flight period. The abundance of meadow grasses and fescues, as well as abundant open, bare ground within the site, and plentiful nectar sources, is likely to make the solar farm particularly


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suitable for this species. Indeed, disturbance to the ground as a result of panel installation may result in an improvement of the habitat for the species, since bare ground is now abundant and this may promote the dry and warm conditions, and grasses, that the species favours. Although the small heath is still a relatively widespread species, the butterfly has undergone a decline in recent decades and contributing factors are considered to be loss of grassland habitat mainly through the intensification of farming and the agricultural ‘improvement’ of grassland habitats. No dingy skippers were re-recorded at the site, despite suitable weather conditions during the surveys. In 2012, only one dingy skipper was recorded within the site, with the majority of other sightings from an area outside of the solar farm. Suitable habitat is present within the site with abundant foodplant (common bird’s foot trefoil Lotus corniculatus) and it is considered likely that the species is still present within the site, albeit in low abundance. As previously discussed, abundance of butterflies year on year may fluctuate naturally and the absence of dingy skipper in 2015 should not be taken as an extinction of the species due to the works undertaken to install the solar farm. The dingy skipper utilises open sunny habitats including chalk downland, woodland rides/clearings, heathland, old quarries, railway lines, waste ground and coastal habitats such as dunes. Suitable conditions occur where foodplants, common bird’s foot trefoil is the usual foodplant, with horseshoe vetch Hippocrepis comosa and greater bird’s foot trefoil Lotus pedunculatus also used, are present in a sparse sward with patches of bare ground in a sunny and sheltered situation. Taller vegetation is also required for shelter and roosting. The dingy skipper is a relatively widespread species in the southern half of the UK but it declined substantially in many areas during the 20th Century. This decline has been most marked in the eastern counties of England and lowland Scotland where the species is now rare, and it is becoming far more restricted in its remaining English and Welsh strongholds. The dingy skipper occurs in discrete colonies, many of which are very small, containing fewer than 50 individuals at the peak of the flight period. It is a sedentary species and unlikely to colonise new areas of habitat unless they are close to existing populations. Although observations of natural colonisations suggest that a few individuals can move several kilometres. It should be noted that during the previous survey the dingy skipper was not recorded in large numbers, only a single dingy skipper was noted within the northern section of the site. The survey found that the most abundant species found within the site is the meadow brown butterfly. This is not surprising as this species is often recorded in large numbers in a wide range of habitats including open grasslands, downland, heathland, coastal dunes, hay meadows, roadside verges, hedgerows, woodland rides/ clearings and waste ground. A wide range of grasses are used as larval foodplant such as fescues, bents and meadow grasses. Other grassland butterfly species, such as marbled white, large skipper, Essex skipper, common blue and ringlet were found throughout the site in 2012 and in 2015. The overall species assemblage appears to have remained unchanged before and after the works to install the solar farm. The re-establishing grassland appears to provide a habitat for a range of butterfly species, including the small heath which remains present. As discussed previously, disturbance to the ground as a result of the works may actually favour a number of species, particularly those which require warm microclimates around their host plants, such as the common blue and small heath. In addition, disturbance may, in the short-term, allow herbaceous plants to become more abundant and thus provide host plants and nectar sources to certain species. In addition, the shade created by the solar arrays has created an opportunity for the speckled wood butterfly which breeds in woodland habitats and uses lanes and tracks between tall hedgerows, parks, gardens and scrub. To conclude, the results in 2015 indicate that small heath are present in similar abundance, that suitable habitats remain for the dingy skipper and that the overall butterfly assemblage remains unchanged since 2012.


In 2016, butterflies were less abundant overall than in 2015. This is considered to be due to overarching environmental conditions and is not considered to be unique to the solar farm. The species assemblage appears to be largely unchanged from 2015 to 2016; small heath butterflies are


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still present but no dingy skippers were recorded. The survey found that the most abundant species found within the site is the meadow brown butterfly. As in 2015, other grassland butterfly species, such as marbled white, large skipper, Essex skipper, common blue and ringlet were also found in 2016. The overall species assemblage appears to have remained unchanged before and after the works to install the solar farm. It is hoped that 2017 will be a much better year for butterfly numbers throughout the country, and that the butterfly surveys in 2017 can provide some further information regarding the species assemblage and abundance of butterflies within the site. It is considered that the results from 2016 are far more likely to be a result of regional and national environmental conditions, rather than any reasons that are specific to the solar farm.

4.3 Botany


Broadly speaking, the installation of the solar arrays does not appear to have significantly affected the unimproved grassland habitat, with a majority of the plant species recorded in 2012 being present in 2015. In addition, the grassland is still considered to be unimproved grassland that meets the criteria of a ‘Lowland Meadow’. However, there are significant areas of bare ground and the grassland under the panels receives higher levels of shading than it did previously. A number of plant species were not recorded in 2015, including the bee orchid, dog violet, eyebright, grass vetchling, hound’s-tongue, meadow vetchling, musk mallow, salad burnet, wild basil and yellow rattle. The species assemblage in 2015 included pioneer species which thrive in bare ground habitats such as the scarlet pimpernel, creeping cinquefoil, fox and cubs, weld and melilot. Shaded areas below the panels have created an opportunity for shade-loving plants such as red campion, garlic mustard, hedge bedstraw and bugle. Certain species, such as the pyramidal orchid and cowslip, were recorded in abundance and may have benefitted from the disturbance to the ground, allowing re-colonisation from the seed bank. It should be noted that works to install the solar farm were competed in the early months of 2015. Therefore, the botanical surveys were undertaken only three or four months after disturbance to the grassland had ceased. Given this, the results from 2015 offer a ‘snap-shot’ of the habitat very soon after major disturbance. Overall, it appears that temporary disturbance has not had an adverse impact on the unimproved grassland. Whilst certain species appear to have been lost, other species have colonised and it is considered that subtle changes in the species assemblage will continue until the grassland has reached a ‘climax’ state after early succession.


The botanical surveys undertaken in 2016 indicate that the grassland under the panels is different in its species abundance and assemblage to the grassland between the panel arrays. Under the panels, tall grasses are abundant and dominant, with herbs in relatively low abundance and low diversity. The majority of herbaceous species are ‘ruderal’ species such as stinging nettle, creeping thistle and dock, with some scrub also present such as hawthorn and dog rose. In sunny areas, between the panel arrays, are more species-rich and grasses area less dominant. The areas between the panels appear to be more indicative of lowland meadow and calcareous grassland, which shaded areas appear more characteristic of species-poor, semi-improved grassland. However, overall the grassland is still considered to be unimproved grassland that meets the criteria of a ‘Lowland Meadow’. Recommendations for the ongoing management of the grassland at the solar farm are provided in Appendix 5. The recommendations are made in order for the panels to remain unaffected by tall vegetation during the spring and summer months, whislt still protecting the botanical interest of the habitat, as well as protected species such as nesting skylarks, within the grassland.


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Control of rabbits may also be necessary, if numbers are becoming high. At the moment, there is no indication that rabbit numbers are having a detrimental effect on the ecology of the site, but rabbit numbers should be monitored in future years and measures taken to control numbers if they are rising to excessive levels.

5 Summary

5.1.1 Summary 2015

In summary, the following key points are concluded from the monitoring in 2015:

Skylarks do not appear to be deterred by solar panels, and are active and attempting to hold territories and nest sites between the panel arrays;

It is considered likely that skylarks are successfully breeding within the solar farm, although there is no definitive evidence of this at present;

Overall, the butterfly assemblage appears to be unchanged and small heath butterflies are still present, seemingly in similar abundance;

The unimproved grassland habitat is still present and still meets the criteria for a ‘Lowland Meadow’;

Disturbance may have lead to the temporary loss of certain species, whilst species of disturbed ground shaded habitats appear to have colonised.

5.1.2 Summary 2016

In summary, the following key points are concluded from the monitoring in 2016:

Skylarks do not appear to be deterred by solar panels, and are active and attempting to hold territories and nest sites between the panel arrays;

Skylarks were observed on the ground between panels and perching on panels. Activity indicative of nesting was observed as well as a small number of possible nests;

Overall, the butterfly assemblage appears to be unchanged and small heath butterflies are still present, seemingly in similar abundance;

Butterfly numbers were lower in 2016 than in 2015. This reflects a national trend in 2016 that is thought to be a result of regional/national environmental conditions;

The unimproved grassland habitat is still present and still meets the criteria for a ‘Lowland Meadow’. The majority of this habitat is found between the panel arrays, in sunny areas;

Shaded areas under the panels are different in their botanical assemblage and abundance of species compared with sunny areas between the panels;

Sunny grassland is more species-rich and grasses are less dominant, there are more species that are indicative of dry calcareous grasslands;

Shaded grassland is relatively species-poor and dominated by tall grasses, the grassland is more characteristic of species-poor, semi-improved grassland.


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6 References

Asher, J., et al., 2001. The Millennium Atlas of Butterflies on Britain and Ireland. Oxford University Press, Oxford. N.A.D. Bourn., G.E. Jeffcoate and M.S. Warren., 2000. Species Action Plan Dingy Skipper Erynnis tages. Butterfly Conservation. Hedenström A. Song flight performance in the skylark Alauda arvensis. Journal of Avian Biology 26: 337-342 Institute of Ecology and Environmental Management (IEEM) - Colebourn, K., Box, J., Byron, H., French, N., Hall, M., Knightbridge, R., Oxford, M., Treweek, J., Wells, M., Ader, K., Moon, S., Archer, J. and Byrne, D., 2006 Guidelines for Ecological Impact Assessment. Institute of Ecology and Environmental Management. JNCC, 2007. Handbook for Phase 1 Habitat Survey - a technique for environmental audit. JNCC Revised reprint 2003, reprinted 2007. Natural England, 2011. Technical Information Note TIN101. Solar Parks Maximising Environmental Benefits. Natural England, Peterborough. Windrush Ecology Ltd, 2012. Proposed Solar Farm at Kencot Hill Farm, Oxfordshire. Protected Species Survey Report. Windrush Ecology Ltd. Windrush Ecology Ltd, 2015. Kencot Hill Solar Farm, near Kencot, Oxford. Ecological Monitoring Report. Windrush Ecology Ltd.


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7 Appendix 1. Results of the 2015 Skylark Survey

Observations of signing male skylarks during the skylark surveys. Red circles indicate the approximate locations of singing males (breeding territories). Circles with associated dates indicate the presence of a displaying male on more than one occasion. Circles without dates are of singing males observed/heard on a single occasion. The location of the skylark plots are shown as brown squares.

1

2

3

15/04/15 01/05/15

01/05/15 21/05/15

01/05/15 21/05/15


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8 Appendix 2. Results of the 2016 Skylark Survey

Observations of signing male skylarks during the skylark surveys. Red circles indicate the approximate locations of singing males (breeding territories). Circles with associated dates indicate the presence of a displaying male on more than one occasion. Circles without dates are of singing males observed/heard on a single occasion. The location of the skylark plots are shown as brown squares.

2

3

1

2

3

27/04/16 25/05/16 27/04/16

08/06/16

27/04/16 25/05/16 08/06/16

25/05/16 08/06/16

27/04/16 08/06/16


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9 Appendix 3. Butterfly Transect Routes Transect Route 2012

1

2

3

4

5

6


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10 Appendix 4. Butterfly Transect Route 2015/2016


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11 Appendix 5. Recommendations for Grassland Management


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Kencot Hill Solar Farm, near Kencot, Oxfordshire Ecological … · 2016. 10. 23. · Kencot Hill Solar Farm is situated to the north and east of Kencot Hill Farm, approximately 2km