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CHAPTER 1

INTRODUCTION TO THE TENTH REPORT OF THE

MOOR GREEN LAKES GROUP

Ken Crick
Chairman of the Moor Green Lakes Group 

It is with some sadness that I commit pen to paper as I relinquish the role of Chairman of the Group. Your new chairman will be Peter Scott, who will be well known to the volunteers who work on the Reserve, and who, I am sure, will make an excellent chairman.

This report marks the tenth anniversary of the Group’s formation. Kevin Briggs has kindly produced a summary of developments over the ten years, presented as an Annex within the report.

This year has been the first in which work was guided by the new Management Plan. We succeeded in completing all the scheduled tasks and some unforeseen extras. One of those extras was the result of the summer break-in to Colebrook Hide, when one view-port hatch was completely destroyed. Entry was achieved through the hatch provided for disabled members, hence the increased strands of barbed wire in. front of this port. The: perpetrators also left some unpleasant personal waste behind them. Towards the end of the summer the hide was left unlocked on a number of occasions. I. can only beg members to be extra vigilant when leaving the hides ensuring they are locked, with all of the combination digits frilly scrambled, A second failed attempt to gain entry to the hide, by forcing the door, was made over the Christmas Holiday period, the door and jam receiving further damage.

Just before Christmas we lost the services of Amanda and Julian Simpson-Atkins, who have led work parties on the reserve for eight years. We wish them well in their new life in Shropshire.

Casual observations recorded toad spawn for the first time on the north shore of Colebrook Lake North at pH Measuring Station A2 (see Appendix F, 2001 Report). Large numbers of whirligig beetles were also in evidence.

All the recorders are to be congratulated and thanked for their sterling efforts throughout the year, as are those of you that complete the monthly sighting record sheets in the hides. Without this input from recorders and members this report and an objective and focused management of the reserve would not be possible.

I would like to thank the members of the committee for their assistance and support throughout my two-year tenure. Also the Blackwater Valley Countryside staff for their advice and work-party leadership, along with those members whose voluntary work on the reserve maintains the diverse habitats and associated wildlife, while keeping the site visibly accessible to members and the general public.

This year’s AGM was followed by a succinct and thought-provoking talk on biodiversity, given by Andy Glencross, Wokingham District Council’s Biodiversity Officer. He helped to put into context our small efforts within the overall thrust for nature conservation within the UK.

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CHAPTER 2

CONSERVATION WORK PROGRAMME

APRIL 2002 TO MARCH 2003

 Sue Dent

The most important contribution to the site management this year was the introduction of the Moor Green Lakes Management Plan, which represents a real step forward in the management of the site. It has been put together by a team led by Ken Crick, who then wrote the plan itself. In its first year the Plan has provided a structure to the work on the reserve and a real incentive, showing that jobs were being done and targets achieved. After its first year of operation the plan will be revised to iron out any wrinkles that have been found and it will then run for five years.

A thank you.. and a farewell

As always the conservation work on the reserve has been enthusiastically supported by volunteers on both the regular Sunday tasks run by the Moor Green Lakes Group and on Tuesdays with the Blackwater Valley Countryside Volunteers. A total of 14 tasks were attended by an average of 11 volunteers - a tremendous total of 155 volunteer days and a huge amount of management work done on the site. Many thanks to everyone who has come along and to the group committee who organise the work to be done so efficiently 

In December Amanda and Julian Simpson-Atkins moved away from the area. Amanda has led the Sunday work parties on Moor Green for three years and has made a huge contribution to the success of the group, not least by helping to establish such a friendly and welcoming atmosphere that volunteers have wanted to keep coming back. They will be sorely missed.

Conservation Tasks

• Keeping islands clear of vegetation. A special effort was made this year to catch up with work on the islands. Tern Island and Plover Island have both been cleared of vegetation to provide the open shingle preferred by breeding birds. Two paths have been cleared across Grove Lake Island; again it is hoped to provide habitat for breeding birds. It was also possible to tackle a substantial area of Long Island, in part thanks to the work of a party of students from Farnborough College of Technology who practised their management skills very effectively on the bramble and gorse.

• Cutting viewing slots alongside the lake, the volunteers cleared one area with the remainder done by Julian Simpson-Atkins as a contractor.

• Grassland. The small meadow next to Colebrook Hide was cut and raked this year. A cut every 3 years will maintain it as rough grassland rather than scrub. The battle with encroaching bramble and scrub on the grassland and willow around the edge of the lake continues, with some substantial areas cleared this year.

• Grazing. It was possible to graze the site rather earlier than usual this year, which meant that the cattle (and calves this year) had time to do their job and leave the site before the ground became too wet and liable to poaching. Many thanks to the volunteers who helped us with checking the cattle during their stay. They are a great bonus to the site management, but we couldn’t manage them without volunteer help in keeping an eye on them.

• Around the Reserve. The area around the entrance to Colebrook Hide was cleared and it is hoped that regular cutting in future will keep the area open. Another stretch of hedge, on the footpath south of Colebrook Hide, has been laid.

• Crassula. The only real cloud on the horizon from the point of view of the management of the reserve is Crassula helmsii, which will be an on-going battle for the foreseeable future. Progress has been slow this year, but we now have permission from the Environment Agency to use herbicide to kill Crassula where it grows along the shoreline. It is hoped that this will limit the impact on bird populations by keeping the scrapes reasonably clear and open. The experiment with using carpet to smother Crassula on Grove Lake has worked, partially. The weed under the carpet is dead, but more has established itself on top. The carpet will be carefully removed in Spring (2003) and any remaining areas will be spot-sprayed.

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 CHAPTER 3

REPORT ON BIRDS FOR 2002

 Dr Ian Brown

At the beginning of the year duck numbers were generally down compared to recent years, but nevertheless there was still a good variety on offer including a record count for the site of 54 Shoveler in February and a Pintail. Goosander still roosted in moderate numbers throughout. There was a very good selection of other species including Barn Owl, Peregrine, a large flock of Brambling, Merlin (only second recorded individual on the site), Mediterranean Gull and Bittern, while the Green Winged Teal remained until late January.

Considering the water levels were relatively high throughout the spring, there was a good selection of passage waders in quality if not quantity, including Black Tailed Godwit, 3 Oystercatchers, an early Wood Sandpiper, Curlew, Greenshank, Dunlin and Little Stint. Other records included the second site record of Garganey, plus Little Egret, Common Scoter and a good scattering of passerines such as Wheatear and Whinchat.

Overall the breeding season was successful for a wide range of species, most notably the first successful breeding of Gadwall after many years of waiting! Waders enjoyed moderate success with Redshank and Lapwing both rearing young, although Little Ringed Plover failed. Once again the most obvious success was of Common Terns with 15 nests on Tern Island, although not all raised broods as a number of nests were deserted. Other notable breeding was of Mandarin, Barnacle Goose, Tufted Duck (several broods), Kingfisher and Grey Wagtail.

Autumn was generally very quiet with a small wader passage, the appearance of 3 Ruddy Ducks (remaining until November), single Firecrest and Brent Goose, the latter of which was only the second site record, the first being in 1984. The year closed with duck numbers building and December records of Peregrine and Little Egret.

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CHAPTER 4

BOTANICAL SURVEY 2002

Dr Delphine Hoyle

Quantitative surveys of the meadow areas on the North and West sides of Colebrook Lake North have been undertaken since 1997. Prior to that overall records of the plants occurring on the reserve have been kept since 1992.

The method used is based on National Vegetational Classification Methodology and the 2002 survey was carried out on 13 July. Ten random samples (1 x 1 metre) were taken, five on the north side and five on the west side of Colebrook Lake North. In each of the sample squares the species present were identified and quantified on the abundance present –

In addition the frequency of occurrence was also recorded -

Table A gives the frequency and abundance of the species found in the samples. Table B lists other species noted in the immediately surrounding areas.

Predominant species have remained remarkably constant over the survey period -Table C - and the majority of originally sown species are still present - Table D. Few new species have appeared over the last five years.

The site has, however, become much more “patchy”, with big areas of nettle and bramble, mainly around the area surveyed.

The help of all those who have taken part in the survey work is gratefully acknowledged.

Table A

Note:  S = Sown species

Table B

Other plants recorded outside the sample squares

  S = Sown species

Table C    Predominant species

Table D   Occurrence of sown species

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CHAPTER 5

REPORT ON BUTTERFLIES FOR 2002

 Recorder Sue Proudley

Butterfly records for 2002 started at the end of March with 4 Brimstone, 3 Red Admiral, 4 Peacock, and 4 Comma.

April and May looked promising with Brimstone, Small White, Orange Tip, Peacock and Comma numbers reaching double figures. It was good to see a better show of Skippers after the dismal records in 2001.

A few Small Copper reappeared in July and September, but no Purple Hairstreaks were recorded.

A single Painted Lady was seen in June, July and August and one Clouded Yellow in August.

We can usually expect to see plenty of brown butterflies from June onward, but these were disappointing with the exception of the Speckled Wood, which did very well. Low numbers of Small Tortoiseshell, Common Blue, and Holly Blue were recorded, and also a single Small Heath.

The last Butterfly recorded was a Red Admiral on 13th November.

Thank you to all the people who have taken the trouble to record their observations. Please keep up the good work and remember to print your name at the bottom of the record sheet so that I can give you the credit.

The list of species observed on the reserve in 2002 is as follows:

The following observers contributed to the records:

Sue Proudley may be contacted on tel: 01252 875536 or

By e-mail: c.proudley(at)btopenworld.com

MOOR GREEN BUTTERFLIES

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 CHAPTER 6

REPORT ON DRAGONFLIES AND DAMSELFLIES FOR 2002

Ken Crick

The early spring was relatively calm and warm with Large Red Damselflies showing a couple of miles further down the valley by the 16th April. However, towards the end of April and into May the weather was unsettled with low light levels, strong winds and low cloud cover.

Emergence of many of our early species was patchy and numbers on the wing were well down on previous years. This variable weather continued throughout much of the summer. Data from three separate weeks were lost due to unfavourable weather conditions. Many of my data sheets for 2002 have statements like "Cloud cover 80% stiff wind from the SE" and "Full sun to start increasing cloud cover 40 to 100%."

Our Management Plan designates Common Darter, Common Blue Damselfly and Blue-tailed Damselfly as species indicative of continuing good management of the reserve’s scrapes and shallows. All three species showed a marked decline in populations on the wing, with Common Darter registering 1/5th of normal annual population level and Common Blue Damselfly being between 1/2 and 1/3 of the annual average. Blue - tailed Damselfly faired no better, with annual average population level down by 1/2 based on the last five years. The data from the five transects indicate that the population decline exists across the site as a whole.

River species did well. Banded Demoiselle figures remained high. Large red Damselfly (that in the main seems to locate itself on Colebrook Cut), numbers held up well.

It was a bad year for Four-spotted Chaser. The Black- tailed Skimmer, with an annual population average of 58, this year only registered 16 specimens. However, this species tends to drift away from mature sites and Moor Green is now ten years old and maturing.

Brown and Migrant Hawker numbers remained respectable. Downy Emerald was seen again. In all 18 species put in an appearance, but 2002 was not a good year. Population fluctuations are expected year-on-year and indeed the records reflect this.

I offer the following factors as possibly contributing to this years collapsing populations of the site’s key monitoring species:-

a) Weather conditions throughout the flight season were generally unfavourable.

b) The five transects routinely monitored are becoming overgrown and shaded.

c) Crassula helmsii infests the shallows of Colebrook Lake North & South.

d) As the site matures some species that prefer newly created sites will decrease.

e) The draw-down zone was less apparent with water levels higher than previous years until late into the summer. Larger fish could hunt right up to the shoreline.

f) Fish populations may be on the increase, with evidence of large numbers of small pike caught during last year’s attempted Crassula helmsii removal.

My thanks are extended to those providing information - they were:-

ODONATA CHECKLIST

DAMSELFLIES Zygoptera

BLUE-TAILED DAMSELFLY Ischnura elegans

This was not a good year for this species. Compared with the numbers recorded over the previous five years the overall numbers seen on the wing were down by over a third. The first recorded sightings were of ten males on the 15th May. There were good numbers present through-out June, peaking at 66 individuals on the 11th. Copulating pairs were observed only twice. A final appearance was registered with a single male on the 27th August.

BANDED DEMOISELLE Caloperyx splendens

This species' iridescent green female continues to cause identification problems, with some observers claiming good numbers of emerald damselfly on the river. Banded Demoiselle had a good year. They were first seen by Cohn Proudley on the 23rd April. There were two population peaks within the flight season, the first on the 26th May registering 260 individuals and the second on the 27th August with 103 individuals. The last recorded presence for the season was on the 17th September. The first population peak was between two to three weeks earlier than would have been predicted based on the previous five years’ data.

LARGE RED DAMSELFLY Pyrrhosorna nymphala

This species had an average year in population terms. It was first reported on the 23rd April, again by Cohn Proudley. Its main haunt is Colebrook Cut in the vicinity of the sluice. The population peaked with a count of 28 on the 21st May and it was last seen on site on the 26th June.

EMERALD DAMSELFLY Lestes sponsa

Recorded numbers for this species are always low. Our best year was in 1999. This year ran it a close second. A total of eight were seen between the 26th July and the 27th August.

COMMON BLUE DAMSELFLY Enallagama cyathigerum

The year started with numbers on the wing comparable with those of 1998 & 2001, remaining this way throughout June. July heralded a population collapse from which only a minor recovery was achieved, with numbers typically 1/2 to 1/3 of the previous worst year. Their presence was first noted on the 15th May. Ninety percent of the 41 seen were in the sexually immature form. The population peak of 576 was recorded on the 26th June, with a second small peak of 160 on the 2nd August. The last sighting was outside the survey discipline and was recorded on the 23rd September, when 2 males were seen.

AZURE DAMSELFLY Coenagrion puellao

Last year (2001) produced the highest population counts to date and even then the maximum numbers seen on a given day only reached 6 individuals. This year the survey only recorded five individuals in total, one on the 26th May, and two on each of the 19th June and 26th June, all males. John Warren recorded two Azures on site on the 27th July.

RED-EYED DAMSELFLY Eiythromma najas

A single male was first seen on the 15th May. Ones, twos and threes were seen throughout June. None were seen in July. Four were recorded on the 16th August, with a final sighting on the 27th August.

DRAGONFLIES Anisoptera

FOUR-SPOTTED CHASER Libellula quadrimaculata

The weekly survey picked up only three Four- spotted Chasers, one on the 21st May and two in June. The member of this species seen by GH on the 19th July was the last recorded sighting for the season. On our reserve 2002 was a very poor year for this species, the second worst since 1997.

DOWNY EMERALD Cordulia aenea

This is the third consecutive year this species has recorded a full life cycle on the reserve. Males were seen over-flying Colebrook Lake North throughout June and on the 2nd June an exuvia was found in almost the same location, as in the previous two years. On the 1st June, Alex Twyford recorded 3 Downy Emeralds on site.

BLACK-TAILED SKIMMER Orthetrum cancellatum

2001 was our best year ever for this species, with 68 individuals recorded. The site average over the previous four years is 55. For 2002 the total count for the flight season was only 16, of which eight were seen on the 11th June, all immature forms. Three exuvia were found on the 19th June, all in the north west corner of Colebrook Lake North. The last sighting of this species was recorded by Steve Farmer on the 19th August.

This species is known to favour new sites and therefore is likely to desert mature ones. The age of our reserve is now reaching double figures and this may account for the very poor showing this year.

EMPEROR DRAGONFLY Anax Imperator

Numbers for this species remain low. A female was seen on the 2nd June and a male on the 26th. The last observation was of an ovipositing female on the 26th July.

BROWN HAWKER Aeshna grandis

2001 was a poor year for this species at Moor Green. 2002 showed an increase in the total numbers on the wing, exceeding those recorded for both 2001 & 2000. The first sighting was on the 13th of July when 9 were recorded over four of the five prescribed transects. An ovipositing female was observed over the Grove Lake scrape on the 27th July during a site visit not associated with the Dragonfly survey work. The final recorded sighting was of three males on the 8th September.

GOLDEN-RINGED DRAGONFLY Cordulegaster boltonii

After last year when this species was not observed over the reserve, a single male was seen twice, once on the 13th July and the second time three days later.
 

BROAD-BODIED CHASER Libellula depressa

A rarely-seen visitor to our site. A single female was observed to the south of Colebrook Lake South, near to the footbridge on the Blackwater, on the 1st June. This species is known to breed locally on Yateley Common.

MIGRANT HAWKER Aeshna mixta

Not quite the lowest yearly population count to date. Numbers are down for 2002 by about one-third based on the previous two years data. This species was on site from the start of August to the end of September and survey counts on a single day of between 5 and 9 individuals were not uncommon. A copulating pair was only seen on one occasion.

SOUTHERN HAWKER Aeshna cyanea

First recorded on the reserve on the 2nd August, they were again observed on three occasions during September. Coincidentally, each survey resulting in an observation of this species recorded the sighting of two individuals. Bucking the trend, this year produced the second highest population count for this species to date.

COMMON HAWKER Aeshna juncea

This not-so-common insect was not seen at all during the course of any population survey visit.

RUDDY DARTER Sympetrum sanguineum

The six Ruddy-Darter sightings were spread over the period between 26th July and 23rd September. They were all males. 2000 & 2001 saw relatively high numbers of this species, but 2002’s data more closely resembles the levels of the late 1990’s.

COMMON DARTER Sympetrum striolatum

The first two teneral-form Common Darters were observed on the 26th June. They were present throughout July, August & September, with a final recorded sighting on the 28th October, when two mating pairs were seen ovipositing in Colebrook Lake North hide scrape. Ovipositing was witnessed on three further separate occasions in September. Again this is the poorest year on the reserve for six years, with numbers on the wing being 1/5 of the annual average over the last five years. The average number seen on the wing for the last 5 years was 300 individuals, with only 66 individuals being observed this year.

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CHAPTER 7

SURVEY OF SOLITARY WASPS AND BEES DURING 2002

Martin Mitchell and Steve Farmer.

During the early summer of 2002 surveys were conducted at Moor Green Lakes on the number of species of solitary wasps and bees observed at three sites. Several years ago three small steep sandy banks had been excavated on the north side of the Colebrook North Lake. These are just below the wooden fence behind Moor Green Farm close to the shore of the lake. For convenience these are called the West, Middle and East Banks. In the intervening years these had become rather overgrown and eroded by grazing cattle. On the Work Party in February 2002 the vertical faces of the West and Middle Banks were re-dressed, but the East Bank was not disturbed. Stout wooden posts were driven in at the corners of each bank to mark the extent of the survey areas. The West Bank is 4.0 metres long by 1.2 metres wide, the Middle Bank is 8.0m by 1.3m, and the East Bank is 4.7m by 1.2m. The West and Middle Banks each include vertical faces about 0.3m high. However the East Bank has a small sloping area of small flints, another small sloping area of hard packed sandy soil and several shallow vertical faces below tussocks of grass. All three Banks face south-south-west and are very well exposed to midday sunshine. The Banks are well drained and the, vegetation in the immediate vicinity is short grass and mixed wildflowers.

During June and July surveys were conducted on 5 days. These had two simple objectives. The first was to count the number of distinct species of solitary wasp and bee observed (without attempting a full identification). Some of these may have been parasitic wasps. Each survey lasted between 30 and 60 minutes. The results of the surveys are given in the table below. On any particular observing day some of the commoner species could readily be recognised as being present on more than one of the banks and these are included only once in the overall total.

The second objective was to count the number of holes which showed recent signs of activity, indicated by small piles of fine sandy soil below the entrances. Most of these holes were in the open bare sections of the banks.

A survey of the wildflowers in the area surrounding the Banks on 18th July showed that there were at least 20 different species in bloom. It was clear that some of the wasps and bees were foraging on these flowers in the immediate vicinity.

In the MGLNR Management Plan, Issue 1, February 2002 in Section 5.7.2 the criterion for favourable conditions prevailing on these vertical exposures of bare ground has been specified. It is deemed to exist if more than two species of mining bee or wasp (from a specified list of species) are observed to be present. During these surveys, while it was not possible to identify the different species observed, it seems clear that the banks are successful. It is also interesting to note that the East Bank seems to be the most successful with more species present and more holes occupied. At this Bank the wasp and bee activity was clearly observed to extend beyond the survey area into the surrounding grassland. This Bank was not re-dressed during the winter and it may be that the West and Middle Banks should now be left undisturbed to encourage more species to return.

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CHAPTER 8

MAMMAL REPORT FOR 2002

 Katrina Slocombe

Roe deer continue to be the most obvious mammal on the Reserve and nearby fields. Stoats are occasionally seen on the surrounding footpaths, but the Water Vole, our most endangered mammal, has again been absent from Reserve and river. This is not unexpected, due to the continued presence of Mink on Long Island. The anti-mink fence around Tern Island may deter the Mink and encourage them to go elsewhere for more ‘easy meals’!

Although no small mammal surveys were possible during the period, it is hoped that populations are being maintained. Certainly hunting by owls on the site throughout the year would suggest that they are continuing to source the reserve grasslands for their mammal prey. The presence of harvest mice is evident from several breeding nests of woven grasses discovered on work party days.

Steve Bailey is continuing a series of Bat Surveys throughout the Blackwater Valley and Moor Green Lakes’ results can be found in the following Chapter.

Surveys and observations will continue in the coming year and members are encouraged to send all sightings of wild and feral mammals to Katrina Slocombe, 28 Green Lane, Blackwater, Camberley, Surrey, GU17 9DH, or pass them to any member of the committee.

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CHAPTER 9

BATS OF MOOR GREEN LAKES

Steve Bailey

Previous Moor Green Lakes Nature Reserve Annual Reports list 5 species of bat recorded on the Reserve. These records mainly stem from a few ad hoc reports and a couple of bat walks on the site organised in the early 1990’s. A detailed report was commissioned as part of the rolling programme of surveys for the site, the intention being:

• to assess Moor Green Lakes Nature Reserve for bat use and bat habitats;

• to describe a repeatable monitoring programme and baseline results;

• to provide recommendations to be incorporated into the management plan that will maintain and improve the value of the site for bats.

Two transects have been set up to collect quantifiable bat data. One of these transects was the length of the River Blackwater on the edge of the Reserve surveyed for Daubenton’s bats as part of a national survey. A second transect on Colebrook Lake was established in 2000 and repeated in 2001 to assess use over the lakes. The forty-three bat boxes erected on site are also monitored annually.

In addition to this, 5 evening visits were carried out in 2002 to look at bat activity around Grove Lake. These surveys and the Colebrook Lake transect used an ultrasonic bat detector with time expansion capability. Bat calls were recorded and later analysed with computer software that gives the best method of identifying bat species without actually catching the bats.

The site was found to have a high value for bats. This high value is due to both foraging on site and also the strategically important flyways, linking the lakes and river on the valley floor to the wooded Finchampstead Ridges.

Bats foraged all around the Reserve, especially the tree-lined river and lake shores. The low fish stocks in the lakes contrast with the habitat of the stocked angling lakes typical of the Blackwater Valley and so provide important variety, adding to the overall value of the Valley. On some nights hundreds of pipistrelles could be seen feeding over the lakes.

The hedgerows linking the Reserve to the wooded areas to the north are important and are used by large numbers of bats of a number of species. Bats are also commuting onto the Reserve along the River and from the south via the tree lined lakes and hedgerows / wooded areas.

No natural roost sites were located on the Reserve, where there are relatively few dead or large mature trees. Probably bats using the Reserve are roosting in nearby houses or trees in the wooded area of Finchampstead Ridges. However, 1 male and 2 female

55 kHz pipistrelles were found in a box sited in the western hedge in September 2002, the first evidence that the boxes are being used.

Four species of bats were observed foraging over the Reserve most evenings and 2 further species were confirmed on site.

The 55 kHz pipistrelle (Pipistrellus pygmaeus) was the most numerous bat recorded on the Colebrook Lake transect in both years (50% of all bats recorded in 2000 and 39% in 2001). The 45 kHz pipistrelle (Pipistrellus pipistrellus) ranked second with 28% in 2000 and 33% in 2001.

This difference may reflect where the transect was located. The 2001 survey indicated that the 55 kHz pipistrelle favoured the tree lined edges of Colebrook South / river corridor, but did move out over the open Colebrook Lake North in June & July to feed on swarms of Caenis Mayfly. The 2002 surveys also found the 45 kHz pipistrelles were more numerous around the lake edges and scrub areas, whereas the 55 kHz pipistrelles were more numerous commuting down the hedgerows and foraging along the river.

Daubenton’s (Myotis daubentonii) bat was the third species of bat that was observed foraging on the Reserve most nights. This species is closely associated with water and is known for its habit of foraging just above the surface of ponds and rivers, which makes it easily visible. Numbers were much lower than the pipistrelles, but, like the pipistrelles, numbers varied from evening to evening, as did the centre of activity. On some evenings the river was well used, on other nights activity was mostly over the lakes. It is likely that during favourable evenings 20-50 Daubenton’s were foraging over the Reserve.

The fourth species that was regular encountered was the Noctule (Nyctalus noctula). Activity was low in the early part of each year, but increased in late May and June. Numbers were lower at Moor Green than the other gravel pits studied in the Valley to the south and they arrived later at Moor Green, suggesting that the Reserve may be at the northern edge of a colony’s territory.

On some nights foraging activity is minimal, with bats visiting the Reserve but not stopping. On other nights, especially in mid summer, 1-5 Noctules forage over the Reserve and adjacent lakes. Although a comparatively small number, the Reserve is playing an important role in supporting a colony of this declining species.

Brown Long-eared bats (Plecotus auritus) are included on the species list published in the Annual Reports. This is believed to originate from a single record of unknown accuracy from a bat walk prior to 1990. They use very quiet calls and so are rarely recorded by echolocation surveys.

Three time-expansion recordings on 27th June 2002 in the car park were confirmed as this species. The bats are almost certainly more common on the site than this one evening’s recordings suggest. It is probable that a colony (usually 10-30 bats) based in the Finchampstead Ridges woodland is using the Reserve as part of its foraging territory.
 

Mixed in with the Long-eared bats were at least two bats that were almost certainly Natterer’s (Myotis nattereri). This survey was just 3 days after recording Natterer’s bat in the Finchampstead Ridges woodland, indicating that a local maternity colony is using the Reserve as part of its territory.

The Natterer’s bat has its international stronghold in southern Britain. Foraging areas include woodlands, wet woodlands and watersides with high tree cover. One of Europe’s major hibernation and swarming sites for this species occurs at Greywell Tunnel. This is well within an evening’s flight range of the Natterer’s bats at Moor Green.

The pipistrelle is a national BAP priority species. Other bat species have probably declined to an equal extent and are equally deserving of conservation measures: Noctules and Natterer’s fall into this category. (Noctules are included in the Bracknell Forest local BAP whilst Wokingham’s BAP includes all bat species).

Because of the site’s high value for bats, there is a need to balance the requirements of the Reserve’s bat population with its other specialities. In general bats benefit from trees and water, as. these provide rich sources of insects and, in the case of woodland, also provide cover and roost sites. Management that aims to increase tree cover and maintain the hedgerows and tree belts that act as flyways is a priority. Cattle grazing should continue as the preferred way of maintaining the areas of rough scrubby grassland, as permanent pasture and dung are a rich source of insects. The increasing diversity of the aquatic and marginal flora will be beneficial to bats, as this also leads to a diverse insect fauna.

For people interested in birds the Reserve may appear quiet and lifeless at night, but it is only a change of shift. With the maturing of the site and minor change to management practices the value of the Reserve for bats should continue to slowly increase. It will be interesting to see the results of any repeated monitoring surveys in 5 years’ time.

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CHAPTER 10

HEDGEROW SURVEY 29TH MAY 2002

Irene Draper and Ken Crick

This survey constituted one of those planned for 2002 (Management Plan Objective 5.5d). The survey was executed on a date that was almost too late in the season as ground-cover plants are not so easily found beneath the early summer flush of grasses and nettles. Many hedgerow surveys are seeking ancient woodland indicator plants in the ground flora. Our hedge was known to have been planted approximately 10 years ago, so the presence or otherwise of ancient woodland indicator plants was not considered to be significant.

The survey was conducted in line with the method taught on the B.B. & 0. Wildlife Trust course. Mrs. Irene Draper, a Group member with knowledge of plants acquired over many years, provided the botanical input. Ken Crick attended the hedgerow-surveying course and assisted with method and data recording.

The survey was carried out on the hedge that runs from the car park at Lower Sandhurst Road (Map ref. SU 805,626) to the River Blackwater. The hedge forms the western-most boundary along which conservation activities take place. The whole length of the hedge was surveyed using a 30-metre line to define each of the 20 survey bays. The height and width of the hedge was assessed using a one metre measuring stick. The record sheets reproduced here were adapted from those used on the course and developed by Dick Greenaway for the Ashampstead Parish, Berkshire, Hedgerow Survey.

The majority of the hedge is overgrown; it contains seven species of standard single trunk trees. The hedge itself is made up of 10 species of shrub. There are a number of large gaps in the hedge. Just how intentional these were in the original planting is not known. Forty-one species of ground flora were recorded as present.

The hedgerow supplement of the first Management Plan, produced at the time the Reserve was created, listed six species of cuttings and transplants to be used. They were oak, ash, silver birch, hawthorn, alder and blackthorn. Five of these are present in the current hedge. The absence of alder may indicate that it was not planted in the hedge, as it does grow elsewhere on site.

Three bays (16,17 & 18) have been laid. The ground adjacent to bays 19 & 20 is particularly shaded and remains damp for long periods. It is suggested that these two bays be scheduled next for laying.

MOOR GREEN LAKES HEDGEROW SURVEY

Date 27 MAY 2002 - START POINT SU8055..E 6260..N

Og - Overgrown

Standard Trees            St = Stool    M = Multi-stem     S = Single

Hedgerow Shrubs

Date 27 MAY 2002 - START POINT SU8055..E 6260..N

Og - Overgrown

Standard Trees            St = Stool    M = Multi-stem     S = Single

Hedgerow Shrubs

Date 27 MAY 2002 - START POINT SU8055..E 6260..N

Ground Flora