MGLG - 1996 Annual Report

This fourth report of the Moor Green Lakes Group covers the period from January to December 1996 for wildlife observations and the period from May 1996 to May 1997 for reserve management activities. A profile of the Reserve is provided at Appendix A and a map at Appendix F.

While overall management of the reserve is under the control of a Steering Group (for details see Appendix A) practical day to day management and the collection, recording, assessment and dissemination of information about the reserve is undertaken by the Moor Green Lakes Group, which now has a membership of about 150. The Group’s Committee Members are listed in Appendix E.

The reserve management Year from 1996 to 1997 has seen further steady progress in pursuit of the Group’s three primary aims, improving the reserve for wildlife, recording and monitoring that wildlife and enhancing the facilities of the reserve for members of the Group and other visitors. In this last category the viewing point alongside the Colebrook Lake hide, which overlooks the wader scrape, has been improved. Additionally, plans have been made for the erection of a second hide, to be provided by Hall Aggregates (South East) Ltd, at the eastern end of Grove Lake. Formal opening of that hide will be in September 1997 (access will be shortest from the Rambler’s Car Park at the entrance to the Horseshoe Lake Water Sports Centre off Mill Lane). The Grove Lake hide has not been modified for wheelchair use and it will not be open to the public except when in use by members of the Moor Green Lakes Group. Access for Members will be on the same basis as for the Colebrook Lake hide.

A considerable amount of conservation management work was again undertaken by volunteers between the 1996 and the 1997 breeding seasons (see Chapter 2 for details) and the Group would like to thank all those members of the Moor Green Lakes Group, of the Blackwater Valley Recreation and Countryside Management Service and of the Farnborough College of Technology who took an active part in this work. We would still like to have more members join our site work parties, even if only an hour can be spared. With a reserve of this size there is a great deal to be done and without this voluntary help there would be a rapid decline in the diversity of wildlife on the reserve.

I would also like to take this opportunity of expressing our thanks to Steve Bailey and to Nick Mutch for the considerable amount of time and effort they have devoted to the running of the reserve over the past year. Steve organises the work parties which means an earlier start and a later finish for him on the day, particularly as he arranges for the necessary tools and equipment, including on appropriate occasions a boat to get to and from the islands. During the past year the interior of the hide has been physically damaged from time to time by vandals and on a number of occasions they have left it in a dirty condition. Nick Mutch has spent a great deal of time undertaking repairs and cleaning up after these incidents and he has been instrumental in keeping the hide open and available for use.

The Group’s wildlife recorders have again been active, Ian Brown for birds, Delphine Hoyle for plants, Nick Mutch for Mammals, Phil Young for dragonflies and Chris Taylor for butterflies. Their individual reports appear in later Chapters together with, and for the first time, a chapter dealing with invertebrates other than dragonflies compiled by Steve Bailey. As the list of plant species has not changed significantly since it appeared as Appendix C in the 1995-96 Report it has not been repeated and reference should be made to that Report for details.

The number of bird species observed on or near the reserve continues to rise and a large number of bird records continue to be received. Ian Brown’s account of the birds seen during 1996 forms a major part of this Annual Report and our thanks are due to Ian for the time and trouble he has taken to produce such a comprehensive account.

A number of volunteer helpers have assisted with surveys and use has been made by Ian Brown and Chris Taylor of the bird and butterfly records left by members and others who visited the hide where record sheets for this purpose are placed. This help is greatly appreciated as it is important that we monitor as closely as possible any changes which take place as the reserve matures. They are a test of the effectiveness of our conservation work. If you can add additional records or have data for other wildlife groups (e.g. insects which as you will see later are woefully under-recorded), please contact the appropriate recorder/committee member indicated in Appendix E.

The 1997 Annual General Meeting of the Group, kindly hosted by Hall Aggregates Ltd, was held at Finchampstead Memorial Hall on 28th February. During the meeting members were given a progress report on reserve activities and wildlife monitoring and advised about the proposals to extract gravel from the fields immediately to the west of the reserve (the “Manor Farm” site). The meeting was followed by an illustrated talk by Kevin Briggs about his ornithological field work during the breeding season at a site in Lancashire, with particular reference to its Goosander population.

For further information about the Group and its activities the contact is either Mark Taylor, telephone 01252-521899 or the Blackwater Valley Recreation and Countryside Management Service (BVRCMS), Ash Lock Cottage, Government Road, Aldershot GU11 2PS, telephone: 01252-331353. If any member notices something happening at the reserve which might result in damage or threaten wildlife, would they please inform the BVRCMS, telephone: 01 252-331353, or Nick Mutch, telephone 01344-771400.

Eleven volunteer tasks were organised during the year attended by 118 people, a marked and pleasant increase upon last year. In addition students from Farnborough College carried out some practical site management tasks. Contractors employed by Hall Aggregates carried out a number of the more intensive jobs under the direction of the Site Manager.

Much work was carried out on fencing . The existing fence around the reserve (all 1.8 km) was strengthened buy the addition of a top wire of barbed wire. A wooden field gate was placed between Grove and Colebrook Lakes to aid access around the reserve. A new post and rail fence was built to control cattle access around the hide and adjacent scrape. Unfortunately due to the death of our grazier, after which his cattle were sold, we were only able to have cattle around Grove Lake.

All the islands on Colebrook Lake were worked on this year. Long Island had many trees removed, patches of bramble were reduced and a large section of its North shore had the grass cut short to attract grazing ducks (this specifically for the Wigeon flock). Snipe Island on which a Swan regularly nests was little touched but all the other islands were cleared of vegetation to leave bare gravel to encourage ground nesting birds. The wire strands around Tern Island were extended to increase the deterrent to Canada Geese, which can trample nests of other species.

The three existing rafts were cleaned and restocked with fresh gravel. Two new rafts were built and launched, one placed in Grove Lake and one in Colebrook North. Both new rafts are bigger than the existing ones and were surfaced with gravel.

A short section of hedgerow alongside the track to the west of Colebrook South was laid. This is the traditional technique for managing hedgerows, and encourages a strong bushy growth low in the hedge so preventing the leggy and gappy growth of hedges that are mechanically trimmed over long

Contractors employed by Hall Aggregates carried out tree clearance on the edges of the lakes. The use of machinery enabled more work to be carried out in a quicker time so reducing disturbance. Trees around the edges of the Lakes were selectively cleared to keep an open aspect to the waters edge.

Trees cut were used to construct a dead hedge alongside the screening barrier to the scrape by the hide. The dead hedge improves the visual appearance of the screen. It also enables the retention of the dead wood on site which is itself a useful habitat.

Other tree felling included the removal of the taller trees within the thickly planted tree belts around the lakes. This is carried out to prevent these tree belts becoming so tall as to affect use of the lakes by wildfowl.

Trees were planted in the young hedge on the approach path to the hide. This thickened the hedge and replaced losses of previous plantings. Stakes and guards were placed around all young trees.

The hide has required continued maintenance and cleaning after repeated bouts of vandalism. An open viewing screen was built next to the hide for the use of visitors who cannot gain access to the locked hide.

The wader scrapes had their banks lowered to give better views into the scrapes and the birds feeding there.

A major operation this year has been the cutting of many viewing points in the tree screens around the lakes.

The year opened with plenty of interesting records including good numbers of wintering wildfowl. Continuing the trend of recent years and in part due to site management, record counts of Wigeon (256 in January), Shoveler (48 in March) and Goosander (up to 124 roosting on the site in January) were made. In addition, a redhead Smew again wintered on the site prompting hopes that this species may become a regular wintering species. Other early year records included a Peregrine (Jan), two sightings of Merlin constituting the first records for the site, a Glaucous Gull, 5 Waxwings which proved very elusive and were again a site first and the last sightings of the ever popular Hoopoe (from 1995), all in February.

Early spring started with a Black Necked Grebe (another site first) which was to remain for a month. Other spring records included Rock Pipit, Grasshopper Warbler, Mediterranean Gull, Sanderling (2 records), Greenshank (very good numbers), Ruff, Wood Sandpiper, Whimbrel, Osprey and a Red Kite (site first).

Breeding success amongst the waders was unfortunately poor with Redshank, Ringed Plover and Lapwing again failing, due chiefly to predation. Tufted Ducks also fared badly having their worst success for many years in sharp contrast to last year! On a brighter note Sand Martin, Whitethroat and Garden Warblers showed a marked increase, Barn Owl was again successful, Mandarins used specially erected nestboxes and Common Terns raised young from nests on the specially built rafts. In addition, Teal and Woodlark (which have not bred previously) may have attempted to breed. One surprise summer sight was that of up to 2 Goosanders, one of which lingered until late June.

Autumn produced several good records, the highlight of which was undoubtedly the unprecedented influx of Little Stints coinciding with a large influx into Britain. Cumulative records involved up to 17 individuals during September. Other records included a Grey Plover in July, a Wryneck in August which was a surprise find and a few Ruff throughout the period.

The late winter period started with a Firecrest in mid November, an early Smew in late November for a few a days, before two were seen from late December into 1997. Eight Bewick’s Swans put in a very brief appearance in early December but the highlight of the period was a Bean Goose which took up residence for a week on the arable land adjacent to the main footpath and was another first for the site!

The surveys carried out on the western side of the reserve (i.e. the surrounds of the two Colebrook Lakes) in 1994 and 1995 did not indicate any great change in species from those found in previous years so no survey was undertaken in 1996.

It was noted, however, that Crassula helmsii - a species that was introduced from Australia and New Zealand - and is difficult to control, continues to extend its range around the lake margins.

The reserve’s mixture of meadow, scrub and hedgerows, supported by the surrounding paddocks and arable land, attracts a variety of mammals - some of which (e.g. Roe Deer) are clearly increasing in number. Up to 10 Roe were observed in one evening, and a doe with two fawns were present in June. The other large mammal frequently observed in the fox, though numbers appear to be small.

Among small mammals there continues to be an active rodent population, particularly in the hawthorn scrub, and well vegetated margins. This year we have had the help of a student carrying out a trapping programme as part of her studies. Her results indicate a healthy population of Bank Vole, Field Vole, Wood Mouse, Common Shrew and Pigmy Shrew.

The reserve’s insect population is visibly abundant and continues to attract four bat species. Sightings and destructive evidence again indicates the regular presence of American Mink.

The number of species of mammals recorded on the reserve remains at 22. The full list is as follows:

Hedgehog

Mole

Common Shrew

Pigmy Shrew

Water Shrew

Dubenton’s Bat

Noctule Bat

Pipistrelle Bat

Common Long-eared Bat

Fox

Stoat

American Mink

Badger

Roe Deer

Rabbit

Grey Squirrel

Harvest Mouse

Wood Mouse

Yellow-necked Mouse

Bank Vole

Water Vole

Field Vole

Erinaceus europaeus

Talpa eropaea

Sorex araneus

Sorex minutus

Neomys fodiens

Myotis daubentoni

Nyctalus noctula

Pipistrellus pipistrellus

Plecotus auritus

Vulpes vulpes

Mustela erminea

Mustela vison

Meles meles

Capreolus capreolus

Oryctolagus cuniculus

Sciurus carolinensis

Microtmy minutus

Apodemus sylvaticus

Apodemus flavicollis

Clethrionomys glareolus

Arvicola terrestris

Microtus agrestis

As there was only limited observation of the dragonflies and damselflies on the reserve in 1996 this report takes the form of a checklist of all species recorded on or adjacent to the reserve up to and including 1996. In each case the status of the species is shown in the form x/x/x, with x indicating the level of the numbers of adults/copulating pairs/ovipositing females observed on a scale from A (a single individual) to F (500+) as explained in the notes and guidelines on dragonfly recording which can be found in Appendix D.

All records of odonata observed on or near the reserve are needed and would be welcomed and should be sent to Ken Crick, 29 Village Way, Yateley Hants GUI7 7SE. If sightings of rare or unusual species can be telephoned to Ken on 01252-872508 this would enable dissemination of the information to other interested observers.

Phil Young, Dragonfly Recorder up to and including 1976 has unfortunately had to relinquish the post due to other pressures on his time. The Group is most grateful to him for all his work as Recorder and is grateful to Ken Crick for agreeing to take over from Phil from 1997.

Recorded from Colebrook Lakes North and South. Maximum recorded counts of dults/copulating pairs/ovipositing females were E/D/D in 1994 and B/A/A in 1995.

Adults recorded from Colebrook Lakes North and South and along the River Blackwater. This species probably breeds throughout the recording area but in smaller numbers than the Common Blue Damselfly. Reported as El-I- in 1994 and (+/+/-) in 1995.

Abundant throughout the recording area as a breeding species. F/D/E in 1994 and (E/+/-) in 1995.

Adults recorded in small numbers from Colebrook Lake North and South in 1994 and from Colebrook

Recorded in large numbers throughout the reserve. E/C/- in 1994 and E/-/- in 1995.

Reported As abundant in 1991-92 at Horseshoe Lake but only recorded as single individuals from

Grove Lake and Colebrook Lake South in 1994 (A/-/-) and from Colebrook Lake North in 1995 (A/-/-).

Large numbers were recorded along the River Blackwater. Smaller numbers were recorded from Colebrook Lakes North and South and also from Grove Lake. E/-/- in both 1994 and 1995.

Scarce. Records of single adult specimens at Colebrook Lake South and North in 1994 but not recorded on the reserve in 1995.

Reported as abundant at Horseshoe Lake in 1991-92 but only individual adults observed throughout the reserve in 1994 (B/-/A) and 1995 (A/-/-)

Reported as present on the reserve in the period 1990 to 1993 but not recorded in 1994 and 1995.

Reported as abundant at Horseshoe Lake in 1991-92. Adults observed on the reserve in small numbers in 1994 (C/A/-) but in good numbers in 1995 (D/A/A).

Individual adult specimens were observed at Colebrook Lake North and South in 1994 and at

Colebrook Lake North in 1995 (B/-/-) both years). The only evidence of breeding was obtained in

A single vagrant male was observed in Colebrook Cut in July 1995 (A/-/-) and there is an earlier report for the period 1990 to 1993 but without specific details.

Large numbers occur throughout the reserve with highest concentrations along the north shores of Colebrook Lake North, Grove Lake and Horseshoe Lake. Assessed as E/B/B in 1994 and D/B/B in 1995.

A single vagrant female with a damaged right hind wing was observed on herbage in the NE corner of Colebrook Lake North in 1994 (the species is normally an inhabitant of boggy pools)

4 single individual of this continental vagrant was observed on the reserve in 1995.

Observed in reasonable numbers from the W shore of Colebrook Lake North in 1994 with an estimated population of C/B/B. Not reported in 1995.

Observed in good numbers from the west shore of Colebrook Lake North and from along the River Blackwater, estimated at D/C/C in both 1994 and 1995.

The following 62 different species have been recorded on the reserve. Any persons visiting the site who wish to submit records of night or day flying moths are encouraged to do so. The contact for records is: Steve Bailey, Blackwater Valley Recreation and Countryside Management Service, Ash Lock Cottage, Government Road, Aldershot GU11 2PS

Angle Shades

Barred Straw

Beautiful Golden-Y

Blotched Emerald

Brimstone

Broad-bordered Yellow Underwing

Buff Arches

Buff Ermine

Buff-tip o????

Clouded Border

Common Carpet

Common Footman

Common Wave

Dark Arches

Dot Moth

Drinker

Dunbar

Ear Moth

Elephant Hawk

Fan-foot

Figure of 80

Flame

Flame Shoulder

Ghost Moth

Grey Dagger

Heart and Club

Heart and Dart

Large Emerald

Large Yellow Underwing

Light Arches

Light Emerald

Lime Hawk

Marbled Brown

Middle-barred Minor

Mother of Pearl

Mottled Beauty

Oak Hook-tip

Peppered

Phoenix

Plain Golden-Y

Poplar Hawk

Riband Wave

Rosy Footman

Ruby Tiger

Sallow Kitten

Setaceous Hebrew Character

Shaded Broad-bar

Sharp-angled Carpet

Slender Brindle

Small Angle Shades

Small Blood-vein

Smoky Wainscot

Snout

Swallowtail

Sycamore

The Clay

Treble Brown Spot

True Lovers Knot

Uncertain

Willow Beauty

Yellow Shell

Yellow-tail

The recording of butterfly sightings on the reserve in 1996 continued in much the same vein as in 1995, with similar numbers of both species and observers contributing to the years records. The recorder is again grateful to all these contributors. A further, but less auspicious, similarity between 1995 and 1996 is that vandalism in the hide again resulted in the loss of some records. However, a number of observers used their ingenuity to ensure that the recorder became aware of the details of these lost records, with the result that the year’s overall picture is much fuller than it otherwise might have been.

Compared with 1995 the species list shows the absence of sightings of Green Hairstreak, Purple Hairstreak, Wall Brown, Grayling and Small Blue. However, none of these had been observed in any abundance in 1995. In contrast the records for 1996 show three species that were not observed the previous year: Clouded Yellow, Painted Lady and Marbled White. The Clouded Yellow sightings related to two days in June - relatively early for this species - and one in August. The Marbled White was observed on a single day in mid-July. There were many sightings of Painted Lady over a period of 5 months, these reflecting a very good year for this species in the locality as a whole.

The continuing absence of sightings of Holly Blue is again disappointing. However, 1997 may well prove to be different, as at the time of writing we seem to be in the midst of a Holly Blue year.

Records for invertebrates other than Lepidoptera and Odonata are very few for the reserve. In total just 10 species have been recorded up to 1996. A BBONT survey prior to 1993 provided records of 6 Orthopteran species (grasshoppers or allies).

This area of the reserves wildlife deserves fuller study. The aquatic invertebrates or the mining bee colony on the exposed banks of Colebrook Lake North are both worthy projects.

To enable a fuller picture of the reserves invertebrates all records are required.

This was a rare species until recently but it has undergone a rapid extension to its range in the 1990’s. It is now one of the commonest Orthopteran species in the Blackwater Valley. Its high pitched singing is a regular feature of hot summer days in many areas of long grass.

A rare species usually found in the boggier areas of heathlands, or heathy woodlands, occasionally recorded from drier situations. Colonies exist in the heathlands around Moor Green, so this could be a record of a vagrant individual. This record requires confirmation.

A small bush cricket usually confined to marshy vegetation such as coastal marshes, the damper parts of river flood plains or pond lake margins. Restricted in distribution to Southern Britain.

A photograph of a Conehead with long wings was taken on the reserve c.1993 that may have been the Long-winged Conehead (C. discolor). C. dorsal/s despite its name can have a macropterous (long winged) form so identification of this individual could not be given to species.

C. discolor was until recently confined to a very few South coast localities but like Roesel’s Bush Cricket has undergone rapid expansion of range in the last two decades. C. discolor can tolerate a wider range of habitat, being able to use drier places and coarser vegetation than C. dorsalis. Both Conehead species are reliably recorded from other sites in the Blackwater Valley, either or both species are possible at Moor Green.

A common grasshopper found in a wide range of dry and sunny grasslands throughout Britain.

A common grasshopper found in a wide range of grassy habitats throughout Britain though often in

A medium sized grasshopper locally common in South East Britain. Usually found in moist habitats such as river flood plains and water meadows. Widespread along the River Blackwater in suitable habitat, though few Berkshire records.

A common black fly that swarms in the lee of trees and bushes in spring. Recorded along the footpath from the car park in the shelter of the hawthorn hedge.

A common marble gall of oak. Parthenogenic females emerge September/ October and over winter as adults, eggs are laid in oak buds in spring. A sexual generation will only develop if eggs are laid on Turkey Oak (Quercus cerris).

One of the ‘House’ spiders. Tegenaria species regularly use sheds and out buildings as well as houses. Recorded from inside the Colebrook hide.

A common Lacewing species found in a range of habitats. About 30 recorded in November 1996 hibernating behind the Dragonfly poster in the Colebrook hide.

All have been observed on the reserve but only in small numbers. Lizard and Slow Worm are also likely to be present but have yet to be observed. Volunteers to spend some time surveying the reserve for this wildlife group would be welcome.

A systematic survey of the lakes on the reserve has still to be undertaken to establish which species of freshwater fish are present but incidental sightings, either during conservation work or while observing fish-eating birds, has produced records of the following:

Other wildlife groups are present on the reserve but have not yet been surveyed, principally because no one familiar with those groups has volunteered to visit the reserve for this purpose.

If you have a knowledge of one of the following groups and some time for a small survey we would be pleased to hear from you:

The contact is Steve Bailey at the Blackwater Valley recreation and Countryside Management Service, telephone: 01252-331353.

The Moor Green Lakes Nature Reserve lies partly within the area administered by Wokingham District Council and partly within the Borough of Bracknell Forest. The River Blackwater, which forms the boundary between the counties of Berkshire and Hampshire runs close to the southern boundary of the reserve. To the north is Finchampstead Ridges, an area administered by the National Trust. A map of the reserve appears at Appendix F.

The reserve covers an area of approximately 36 hectares (90 acres), the majority of which lies within the flood plain of the River Blackwater. It contains three lakes formed out of flooded gravel pits which are bordered by areas of grassland, planted coppice and wildflower meadow. Two of the lakes, Colebrook Lake North and Colebrook Lake South, are separated by an elongated island through the centre of which runs the old water course of the Colebrook Cut. The third lake, Grove Lake, lies immediately to the east separated by a narrow strip of land. Within the lakes are several gravel-capped islands and gravel beaches.

An important feature of the reserve is the presence of sluices, at the exit of the Colebrook Cut and from Colebrook Lake into the River Blackwater, which allow the level of the water in Colebrook Lakes North and South to be controlled within limits so that muddy margins can be exposed ahead of the main spring and autumn passage of wading birds.

Overall management of the reserve is under the control of a Steering Group comprised of representatives of Hall Aggregates (South East) Ltd, Berkshire County Council (the planning authority), Blackwater Valley Recreation and Countryside Management Service and the Berks, Bucks and Oxon Naturalists’ Trust. Practical day to day management and the collection, recording, assessment and dissemination of information about the reserve is undertaken by the Moor Green Lakes Group established in 1993. The Group’s Committee Members are listed in Appendix E. The necessary costs of the Group not covered by membership subscriptions are met by Hall Aggregates (South East) Ltd. Membership is open to all with an interest in the reserve, its wildlife and its management,

Public access to the reserve is restricted to the viewing hides provided by Hall Aggregates (South East) Ltd which overlook respectively Colebrook Lake North and Grove Lake (see map at Appendix F). Unfortunately vandalism has meant that the hides cannot be left permanently open but every effort is made to open the Colebrook Lake hide each Sunday from about 9am to 4pm and members of the public can use the hides whenever they are in use by members of the Group (who have access at any time). The Colebrook Lake hide incorporates a viewing window for observers in wheelchairs. When the hides are locked, views over the scrapes adjacent to the hides can be obtained from the screened viewing points alongside the hides. Views across the reserve can also be obtained from points along the footpath which runs along the western and southern sides of the reserve.

The main access to the reserve is from Lower Sandhurst Road where a car park has been provided (Ordnance Survey grid reference SU805628). The shortest access to the Grove Lake hide is from the Rambler’s Car Park at the entrance to the Horseshoe Lake Water Sports Centre off Mill Lane (grid reference SU820620)

LITTLE GREBE Resident and winter visitor, but declining. One pair possibly attempted to breed. The poorest breeding season since records began.

GREAT CRESTED GREBE Common resident. A maximum 16 was recorded on March 17th. A total of five pairs were present during the summer, one pair successfully rearing 1 young.

BLACK NECKED GREBE A first winter bird present from March 3rd to April 2nd (DH et al) was the first record for the site.

CORMORANT Common winter visitor which occasionally oversummers. Numbers peaked at 49 on Dec.23rd (KBB), a record count for the site.

MUTE SWAN Common resident and winter visitor. Two pairs reared a total of 7 young. The maximum count was 42 on Nov.13th.

BEWICK’S SWAN Eight circled for five minutes on Dec. 7th before leaving NE (NRP), only the second record for the site the last being in 1992.

TAIGA BEAN GOOSE One of the fabalis race present from Dec.14th to 21st (IHB et al) was the first record for the site. The bird (independent from other geese) frequented the arable land adjacent to the main footpath and roosted on Colebrook Lake North each evening. The bird arrived at a time when there was a large influx of Bean Geese into eastern England.

GREYLAG GOOSE Regular visitor. One to five birds were recorded on eight dates between March 17th and Sept.5th.

SNOW GOOSE Common resident, with birds from the nearby free flying flock regularly visiting the site. The maximum count was of 29 on many dates. Five pairs attempted to breed but were unsuccessful.

BARNACLE GOOSE Common resident. The local feral population continues to increase. A maximum of 124 were recorded on many dates and in addition this flock contained 5 Barnacle x Canada hybrids. Four pairs attempted to breed unsuccessfully.