CEMEX greatly welcomes the publication of this 14th Annual Report and remains committed to the support of the Moor Green Lakes Group and its continuing management of the company’s nature reserve, It looks forward to the expansion of the Group’s activities into the adjoining mineral workings as their restoration nears completion.   CEMEX UK Materials Ltd CEMEX House Coldharbour Lane Thorpe, Egham Surrey TW20 8RA Tel.0193258383600                                                                                                  July 2007   CEMEX UK Materials Limited CEMEX House, Coldharbour Lane, Thorpe, Egham, Surrey TW20 8RA, United Kingdom. Phone: +44 (0) 1932 583600 Fax: +44 (0) 1932 583611 www.cemex.co.uk Registered in England and Wales: Company Number 4895833 Registered Office: CEMEX House, Coldharbour Lane, Thorpe, Egham, Surrey TW20 8TD, United Kingdom

[Previous Year]       [Previous Section]       [Contents List]       [Next Section]         [Next Year]

CHAPTER 1

INTRODUCTION TO THE FOURTEENTH REPORT OF THE

MOOR GREEN LAKES GROUP

 Peter Scott

Our wildlife recorders have once again produced, here, a thorough overview of the reserve during 2006. On the whole it indicates that habitats on the site continue to attract large numbers of most animal groups, decreases in some species being balanced by increases in others. An exception is reptiles, which suffered a marked decrease last year. However, a single year’s data is insufficient to confirm a problem, especially for animals which are not seen in large numbers at any time. A second ‘poor’ year would be a little worrying.  

In addition to the ‘usual’ chapters, our annual reports sometimes include extras describing surveys that are not made every year. There are two examples in this edition. Steve Farmer describes his observations of bumblebees made last summer. It is always encouraging to find that we host species that we are, perhaps, not usually aware of. Kevin Briggs, in one of his final contributions to the group’s work, carried out a common-bird-census-style survey of birds’ breeding territories. Chapter 4 describes his findings. This is a survey that, ideally, should be made every 5 or 6 years. It was previously done in 2000, and comparison of the two years’ results is, again, quite encouraging.

Kevin has now left the area, retiring to his native Lancashire. His varied contributions to the group since its foundation have been enormous and it will not be easy to fill all the gaps he leaves behind. Certainly no single person can match the combination of skills and experience that he brought to his tasks: we can only cover them to the best of our joint abilities.

Another founder member who has stepped down this year is Delphine Hoyle, and the botanical report (chapter 5) will be her last. Fortunately Delphine has agreed to assist with future plant surveys, so her expertise will not be completely lost just yet. As nobody has yet offered to act as plant recorder, I am filling the role for the time being. However, it is bad policy (for the group) to allow a situation to develop in which one person does several jobs, as replacing them when they eventually retire becomes extra difficult. So we are in great need of one or more people to take over as plant recorder or reptile recorder.

Controlling the water level in the lakes once again proved difficult. CEMEX’s clearance of the blocked outlet pipe in the south-west corner was unfortunately only temporary. That pipe has now been converted to an open culvert over much of its length, making future clearance easier. However, by the time this was done the water had been very high for several months. Not only did this reduce the area of exposed mud (beloved by wading birds), but it was also a probable cause of the fence on Tern Island being undermined by wave action. The fence has been repaired, but the ‘treatment’ may not be effective in the long term, so we may need to install further protection. Although the effectiveness of the fence is not certain, we believe that it should be maintained: the loss of so many gulls and terns last year through predation (see chapter 3) may have been at least partially a result of the fence failing.

Developments at Manor Farm, to the west of the current reserve, are gradually increasing in their effects on our work. In chapter 2 Sue Dent mentions some of the manual tasks carried out there, not least some initial planting of reeds to get the proposed reed bed started. Ian Brown’s bird reports have included that area for some time, of course. In fact, many of the rare visitors that cause so much excitement seem to prefer the ‘dereliction’ of the gravel workings to the habitats we work so hard to provide! Of the two barn owl boxes installed in autumn 2005, the one on Manor Farm has so far been the more successful.

CEMEX have continued their input to the work, notably by paying for the coppicing of the perimeter woodland and by copying this report and our newsletters for us. We hope that their commitment will continue after they have finished quarrying in the area.

Finally I would like to thank one other person for her efforts. Although she no longer appears in the list of committee members in appendix G, Chris Rose has once again collated this report, including a certain amount of retyping after my editing.

[Previous Year]       [Previous Section]       [Contents List]       [Next Section]         [Next Year]

CHAPTER 2

SITE MANAGEMENT REPORT

APRIL 2006 TO MARCH 2007

 Dr Sue Dent

Countryside & Access Officer

Blackwater Valley Countryside Partnership

General Site Management 2006/7

Plantations to southern edge of reserve

The rotational cutting of the plantation has continued, including some blocks that have never been cut and which were beginning to create a significant woodland edge to the reserve. For the second year some newly cut trees have been protected with mesh tree guards to prevent grazing by deer, and occasionally by straying cows. This seemed to work well last year and re-growth has been strong.

Scrub control

The annual scrub and bramble control has been carried out. Stump treating the scrub around the lake edges help to keep the job manageable. The bramble remains an issue and we are considering some limited spraying next year. This will concentrate on Tern and Plover Islands where a total clearance of vegetation is ideal. This will free up the volunteer work parties to tackle other tasks around the reserve.

Grassland management

Cattle have grazed the reserve again this year from September until December. They do an excellent job of grazing off the vegetation, but it can be very difficult to get them moved on when their job is done and before they start to poach the ground. However, the balance is still very much in favour of grazing as a method of managing the grassland areas.

Islands and scrapes

The management of Long Island has been a priority this year with a lot of bramble and scrub being cut back right across the island. A survey of the six scrapes around the island in August 2006 found that the 3 northern scrapes were quite acidic and contained little invertebrate life while the overgrown scrapes to the south supported were very diverse and provided very good invertebrate habitat. A management plan for the scrapes has been written which balances the value of the scrapes both as invertebrate habitats and as feeding places for birds.

Tern and Plover Islands have been mostly cleared of vegetation. After the major re­working of the Colebrook and Grove Scrapes in 2005/6 the main bunds have been cleared of vegetation to maintain them as bird feeding areas.

Himalayan Balsam

This invasive species has now extensively colonised the river corridor but not the main reserve area. Pulling and cutting the plants before flowering does seem to give an element of control and this will be continued.

Water level management

A combination of high rainfall and a blocked outlet pipe from Colebrook Lake meant that for most of this year it wasn’t possible to control water levels in the lakes. However the pipe has now been opened up into a culvert and it is hoped that this will give better control next year.

Other reserve matters

Two stag beetle buckets were installed as part of a project being run by the People’s Trust for Endangered Species. The buckets are filled with wood chip and provide a way of monitoring the presence of stag beetles. They will be dug up again and checked for the presence of larvae.

There is a new notice board on the path down to the hide. It was funded jointly by Wokingham District Council and Cemex.

There was some unauthorised use of the lakes for swimming in the summer but the group was eventually deterred by being regularly told that they were not permitted.

Conservation Volunteers

As always the management of the reserve is only possible because of the hard work and support of a dedicated band of volunteers, both from the Moor Green Lake Group and the Blackwater Valley Countryside Volunteers.

The Moor Green Lakes Group has been out for 7 Sundays from September to March. Overall they have done 70 person-days of practical work, with an average of 10 people out on the Sunday Tasks. Special thanks to Peter Scott, Simon Weeks and Tim Mockridge who have led the Moor Green Lakes Group tasks this year. This has been backed up by the Blackwater Valley Tuesday group, who has done 7 tasks and 139 person-days.

Which all comes to 209 days of volunteer effort, or over £11 thousand pounds worth of work.

Extra thanks to Peter Scott who plans the practical work, and makes sure that the volunteer teams know what needs doing each month, and to Simon Weeks, the Site Liaison Officer, who keeps an eye on the site on a day to day basis, and checks on cattle while they are on site.

Manor Farm

The current working site to the west of Moor Green is now being restored and much of the eastern side of the site, adjacent to Moor Green, now has it’s final levels and land form, including much of the new reedbed area. Two task days have been spent carrying out planting trials of reeds to find out the best way of colonising the new reedbed area. A variety of methods have been used including stem cuttings, rhizome cuttings and planting out rooted cuttings. The new plants have been surrounded by low mesh fences to protect them from feeding by geese.

Moor Green Lakes, Volunteer Tasks, Apr 06 — March 07

[Previous Year]       [Previous Section]       [Contents List]       [Next Section]         [Next Year]

CHAPTER 3

 REPORT ON BIRDS 2006

Recorder: Ian Brown

During the year 142 species were recorded (a site record) of which 67 were present in suitable breeding habitat in the summer. This equals the previous best year (1996) for breeding species and is the second highest annual recorded total equalling the number of species recorded in 1997. These figures partly reflect habitat improvement and increased habitat diversity. Two new species was added to the site list, Red Footed Falcon and Ring Necked Duck, bringing the total number of species recorded to 207.

In the early winter period waterfowl numbers were generally good although Wigeon were present in significantly lower numbers than usual whilst site record counts were made of Gadwall (262 in February), Pintail (10 in January), continuing the recent trend as a regular wintering species, and Shoveler (117 in March). Tufted Duck numbers also increased. Little Egrets were again regular visitors, whilst a flock of 40 Golden Plover was a site record. Barn Owls regularly used the boxes and good numbers of Brambling were present on stubble to the west. Other records included an unseasonal Redshank, and a leucistic Red Crested Pochard.

Waders began to move in early March with Curlew and Dunlin before arrivals of Little Ringed Plover and Ringed Plover (with a good showing of spring records). March ended with a flurry of good records including the first record of Sanderling for that month, a fine summer-plumage Mediterranean Gull, Little Gulls and Common Tern (second year running with March arrivals). Good birds continued into April with Osprey, several Red Kites, a singing Grasshopper Warbler, a few Whimbrels, more Little Gulls, two Arctic Terns and an exceptional passage of Wheatear with numbers peaking at nine. A winter-plumage Bar Tailed Godwit was notable since it lingered for more than a day and was seen by a number of observers, only to be surpassed in May by a fine bird in full summer plumage that frequented the pools to the west of the bridleway for four days! May is traditionally a very good month and this year was no exception with the main highlights being a short-staying Little Tern, the first for twelve years, and a Short Eared Owl for the second consecutive year, but both birds were only seen by single fortunate observers. Other birds included three Arctic Terns, a Black Tern, Whimbrel, Turnstone, two Sanderling, Nightjar and a record count of 94 Common Terns.

Overall it was a very good breeding season with waders and waterfowl in particular moderately successful, including Redshank (3 young), Lapwing and Little Ringed Plover. Tufted Duck enjoyed one of their most successful seasons with at least ten broods, whilst Gadwall, Mandarin and both grebe species reared young. Egyptian Geese were successful for the third year running rearing 14 young. Black Headed Gull and Common Tern largely failed due to predation, with mink the chief suspect. Other species that had a good breeding season either on the reserve or nearby were Little Owl, Buzzard, Hobby, Kingfisher, Grey Wagtail and Skylark. Breeding may have been attempted by Sand Martin and Red Legged Partridge, in the case of the latter the first possibility for 12 years.

Consistent with recent years July was an excellent month with bird of the year being a Red Footed Falcon (first for the site) that stayed for at least five days. The bird entertained many observers during its stay and was entirely unexpected, initially providing an identification challenge as a first year female. Other records during the month included a pair of eclipse Garganey, a party of four Black Tailed Godwits and singleton Wood Sandpiper and Oystercatcher. August’s highlights were a long-staying Spotted Redshank (most records relate to one day visits), a site record count of 12 Green Sandpipers, Ruff and Redstart. Notable autumn records were record counts of Greylag (101) and Egyptian Geese (69) at roost, a party of five Little Stints in October and a late Osprey in November.

The year ended with another site first; a female Ring Necked Duck was present for a single day in November. This duck a vagrant from North America, spent time either side of this sighting on nearby Yateley Gravel Pits. Other records included Peregrines, Red Kite, two Smew and a site record count of Little Egret (7).

Again my thanks go to the growing band of observers who submit records, especially including those who provide observers names on the log sheet. In particular I would thank the small band of stalwarts covering the site on a daily basis irrespective of weather!

[Previous Section]       [Contents List]         [Next Section]

CHAPTER 4

ORNITHOLOGICAL MONITORING 2006

Dr K B Briggs

Ten field visits were undertaken from mid-March to mid-July, totalling 33.30 hours, to record the status and position of all birds on the reserve in 2006, using standard BTO Common Bird Census methodology. Supplementary data was added from the nest box recording visits. The field information was transcribed to species’ maps, cluster analysis undertaken, territory maps were drawn and a report produced totalling 72 hours.

The results are given in Table 1, which also gives comparable figures for the 2000 survey. The conservation status of each species is also given and the change in population at Moor Green and for the southeast of England, based on the national BBS Survey. In total, 85 species were recorded, 62 were breeding and 1001 territories located and 53 definitely bred within the reserve fence.

A closer look at Table 1 shows that 13 species present in 2000 were not recorded in 2006, of which Hobby, Little Owl and Spotted Flycatcher were territorial. The converse is the addition of 12 new species for 2006, of which Greylag Goose, Egyptian Goose (both feral), Black Headed Gull (most territories), Barn Owl, Reed Warbler and Treecreeper are territorial.

Eleven species present in 2000 have changed status to territorial in 2006 (Gadwall, Teal, Snipe, Buzzard, Collared Dove, Lesser Whitethroat and Goldcrest), whilst Snow Goose, Hybrid Goose, Skylark and Starling are demoted from territorial in 2000 to present in 2006.

The report highlighted the reserve management to maintain the red and amber listed species populations, which are currently stable or increasing. Habitat management and facility provision (nest box and artificial feeding) are working well.

Table 1

Bird Species and Number of Territories of Breeding Species recorded in 2006 and 2000

 Key

[Previous Year]       [Previous Section]       [Contents List]       [Next Section]         [Next Year]

CHAPTER 5

BOTANICAL SURVEY 2006

 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. The 2006 survey was carried out on 24 May on the north side and on 21 June on the west side. Ten random samples (1 x 1 m) were taken five on each side. The National Grid References of these sites are as follows:

These sites are also shown on the site map at Appendix I

 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 sample squares. Table B lists other species noted in the immediately surrounding areas in column B1. Two other sites were also surveyed. These were the Colebrook Cut Wood and the Corner Wood. The additional species found at these two sites are given in columns B2 and B3. Table C shows the changes in some of the predominant species between 1997 and 2006.

Black Knapweed, Lady’s Bedstraw, Cut-leaved Cranesbill, Ox-eye Daisy, Lesser Stitchwort, Ribwort Plantain and Clover were all abundant this year. While Perforate St John’s Wort, Sheep’s Sorrel and Common Vetch were present on the north side they were not found in the squares on the west side.

Eighteen of the original sown species were found. There was little evidence of tree or shrub seedlings though brambles continue to spread in the surrounding areas but are cut back regularly. Few new plant species have been found in the last ten years.

Thanks are due to Doreen Dye, Irene Draper, Steve and Sheila Farmer and Peter Scott for their help with the main survey and to Peter Scott for the surveys of Colebrook Cut Wood and the Corner Wood.

Table A

Note:  S = Sown species

Table B

S = Sown species in area covered by B1 only

Table C Comparison of some predominant species between 1997 and 2006

[Previous Year]       [Previous Section]       [Contents List]       [Next Section]         [Next Year] 

CHAPTER 6

REPORT ON BUTTERFLIES FOR 2006

Recorder Sue Proudley

No butterflies were recorded at Moor Green during February and March 2006. The first butterfly to be recorded was a Comma on 5th April. The first Brimstones, 7, were recorded on 12th April together with 6 Commas.

Despite the late start 29 Brimstones were recorded in May, which is the highest number for four years, 10 in June and 2 in July. Large White and Small White numbers were slightly up on the 2005 records but Green-veined Whites were lower. Only 27 Orange-tips were recorded in May.

Very few Small, Essex and Large Skippers were recorded.

Speckled Wood butterflies did not do as well this year peaking at 30 in September. Meadow Brown, Gatekeeper and Ringlet numbers were one third of those recorded in 2005.

3 Green Hairstreaks were recorded in both April and May, 3 Purple Hairstreaks in August only one Small Copper was found in June and again in August. Holly Blues were recorded each month from April to August the highest number being 4 in May.

6 Common Blue butterflies were seen in August.

Small Tortoiseshells remain scarce. The highest number recorded was 6 in May. Peacocks did little better. Red Admirals showed well from May until October. Commas were also more abundant than in 2005 with 24 recorded in July.

One Marbled White was found in July.

One Painted Lady visited in June and was recorded again in July and September. There were no sightings of Clouded Yellows or any other unusual visitors.

The last butterfly recorded was a Red Admiral on 30th November.

The list of species observed on the reserve in 2006 is as follows:

Number of species 24                               

I would like to thank 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 record sheet so that 1 can give you the credit.

The following observers contributed to the records in 2005:

Sue Proudley may be contacted on tel: 01252 875536 or

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

MOOR GREEN BUTTERFLIES

[Previous Year]       [Previous Section]       [Contents List]       [Next Section]         [Next Year]

CHAPTER 7

REPORT ON DRAGONFLIES AND DAMSELFLIES FOR 2006

 Recorder Ken Crick

The data collection protocol outlined in last years report was adhered to for the 2006 season. The long cold spell from late winter continuing through early spring significantly delayed the onset of the flight period for most early-season damselflies. Southern England was particularly affected and Moor Green was no exception.

Visits to site during April and late September produced no records. An explosion of activity and an early cessation of the flight season followed the late start. Only 12 survey visits provided data. In all 19 species were observed on the wing. Nine species were observed copulating and/or egg laying. The exuviae of 8 species were found in the emergent vegetation.

Whereas the number of species seen on the wing was 2 higher than last year, the number of species demonstrated to have completed a full life cycle on site was two lower than last year.

I was particularly grateful to Mr. Ray Reedman who provided a photograph taken on the 3lst July at Moor Green of a female Golden-ringed Dragonfly. This is the first independent confirmation of the species making its annual appearance at Moor Green. The steep-sided cut channelling water from Grove Lake to Colebrook Lake South has had male Golden-ringed Dragonflies patrolling it intermittently over a number of seasons. This year in an attempt to make the cut more attractive to this species, a dam was constructed with natural materials gleaned from Moor Green. The dam backs up the water in part of the cut, creating a relatively slow flowing zone. Water continues to pass through the dam and in times of spate cascades over the dam. Experience has shown that these slow flowing areas are often rich in aquatic invertebrates, food for any Golden-ringed larva.

Another new habitat has been created albeit probably transient, on the Grove Lake major scrape. The new bund wall dividing the scrape has created a marsh-like area of medium acidity pH 4.7 and above. This area has attracted Black Darter and Keeled Skimmer. Local conditions currently mimic those of nearby Wildmoor where both species can be found.

The last reported sighting for the flight season was made by S Farmer with three male Common Darters seen on the 18th November.

My thanks go to those members providing information on the hide charts, who were J Warren, S Proudley, R Eagling, I H Brown and ‘No Name’ twice.

Ian Brown, who covers far more of the site than I do, recorded upwards of 5000 Common Blue Damselflies on the wing on the 17th June.

ODONATA CHECKLIST

2006

 DAMSELFLIES Zygoptera

 *There is little doubt that this species is breeding at Moor Green; I just failed to pick up any exuviae this year

DRAGONFLIES Anisoptera

[Previous Year]       [Previous Section]       [Contents List]       [Next Section]         [Next Year]

CHAPTER 8

REPTILE REPORT FOR 2006

 Peter Scott

Reptile recording on site has two components:

•  regular inspections of ‘basking sheets’ (and their surroundings) in two areas:

a) six sheets within 50 metres of the hibernaculum near Colebrook Lake North;

b) three sheets spread along a 200-metre section of the north shore of Grove Lake;

•   casual reports of sightings anywhere on the reserve.

Regular Inspections

Fourteen sheet-inspection visits were made between April and October. All nine sheets were checked each time. Once again, the majority of the visits produced no sightings. The remainder found individual snakes under various tins. On no occasion were two or more snakes found together, unlike the preceding three years. The overall results are summarised in the following table:

Summary of Surveys of Reptile Basking Tins

The decrease from the previous three years is marked. As usual, the small scale of the survey must be borne in mind when interpreting these results, but it seems that the stable situation of 2003-5 has been broken. The most obvious change to the local environment is the new barn owl box, installed in autumn 2005 close to the reptile hibernaculum. It may be that snakes feel threatened by this potential ‘look-out post’ for predators (not necessarily barn owls, which tend to be most active when reptiles would have ‘retired for the night’, but also kestrels, which have used the box). This is supported by the fact that sightings at the tins along the north bank of Grove Lake, though few, are little-changed from last year, so that the decrease is entirely at the tins close to the hibernaculum (and the barn owl box).

Casual Reports

Only four reptiles (three grass snakes and one adder) were reported, compared with 9, 10 and 16 in the previous three years. This, if genuinely due to a decrease in reptile numbers rather than less enthusiastic reporting, might indicate that the decline found at the basking tins was general around the reserve and not, after all, an effect of the barn owl box.

Summary

There appears to have been a decrease in reptile activity on the reserve in 2006, especially in the area around the hibernaculum. Results for 2007 may help us decide whether the siting of the barn owl box is a factor in this.

I am grateful to those (Les Thorn, Steve Farmer, Noel Silver and ML) who reported seeing reptiles. Please take the trouble to note your sightings on the forms in the hides.

[Previous Year]       [Previous Section]       [Contents List]       [Next Section]         [Next Year]

CHAPTER 9

MAMMAL REPORT 2006

 Recorder Ian White

The site has had its usual run of deer, squirrels, weasels and foxes - just what you would expect on a nature reserve. But there were two surprises in 2006; one was good news and one bad news.

The bad news first. After a warning in 2005 that there had been some damage to eggs on Tern Island, people wondered who the culprit was. Was it a fox or was it mink? Due to an increased number of sightings in 2006 it seems almost certain that it was mink.

Most people will be familiar with mink, but here is a brief overview. They are in the Genus Mustela (Latin: weasel) along with our native Stoat Mustela erminea, weasel Mustela nivalis and polecat Mustela putorius. In spite of this very close relationship with these other species we commonly recognise mink, and of those there are just two species. The European mink Mustela lutreola and the American mink Mustela vison. Unfortunately, we don’t have the one we should have had, the European mink which is a declining species; instead we have the American mink which in this country is something of a pest. They were introduced to Britain in 1929 to be bred for their fur. Inevitably some escaped and there were also some releases from farms by animal liberation groups. A BBC report from August 2000 stated:

A spate of attacks on mink fur farms, which released thousands of the creatures into the British countryside were called “catastrophic” by the RSPCA. The society feared the voracious mink would decimate local wildlife.

However, by that time mink were already established in the wild and the majority of those released, which were not used to fending for themselves in the wild, were rounded up the morning following their liberation in the local car park!

Mink tend to have a long narrow territory; the size of which varies but may be several miles in length and is generally centred on a watercourse. They can be active at any time of day or night.

Mink are voracious predators and are thought to be instrumental in the catastrophic decline of the water vole. The water vole’s usual method of defence is to use an underwater burrow to escape danger to its nest. A female mink is small enough to enter the burrow and pursue the vole, which then becomes a large snack. They are also a serious threat to waterfowl, game birds, poultry and fish.

There have been suggestions that the expanding population of otters may have a future effect on mink numbers. Early work in Oxford suggests that what may be happening is that as otters are nocturnal, mink change their behaviour to become predominantly diurnal, so that the animals reduce their chances of meeting.

So why are they back? It may be that trapping in the area has been reduced, or that there has been a population explosion and hence expansion from the Basingstoke Canal where they are prevalent. We will be putting a couple of mink rafts in an area of the lake to identify how serious the mink problem has become before deciding what we can do about it.

On to the good news. Harvest mice are back! Did they ever go away — who knows? They are our smallest rodent and our second smallest mammal (the honour of the smallest is taken by the Pygmy shrew at 4g which itself is the second smallest mammal in the world). The Harvest mouse weighs in at 5-6 grams and its size is alluded to in its scientific name of Micromys minutus. Gilbert White, a naturalist who lived in Selborne, Hampshire, first described it accurately in 1767; he found it living in cornfields around his village - hence the name ‘harvest mouse’.

Harvest mice are very active both day and night. They are agile little animals, using their prehensile tail as a fifth limb to grasp grass stalks. What is eaten depends on what is available; in early spring, the mouse eats buds on bushes, new grass shoots and nectar from flowers. Seeds from crops are mainly eaten during the summer but insects such as wheatfly aphids, blackfly, grasshoppers, moths and caterpillars are also relished. Blackberries and rosehips are eaten in the autumn.

They are sufficiently small that they are very hard to find and usually their presence is only indicated by the discovery of a woven nest supported on grass stems, which is about the size of a tennis ball.

Man has never deliberately persecuted harvest mice since their small appetites do little to affect crop yields. They even do the farmer a bit of a favour by eating harmful pests such as aphids. However, they seem to be less numerous in cornfields than they used to be. This is most likely due to changing farming methods such as combine harvesting, reduced stubble length and crop spraying.

Harvest mice must have shelter to retreat to once the crop has been harvested, so hedgerows are an important habitat for them, providing food as well as shelter. When hayricks were more common, many mice over-wintered in these.

What is the status of harvest mice now? The truth is no one knows. They have been little studied and more survey work needs to be done to ascertain how widespread or endangered they are. Again a preliminary study in Oxford studied a good population at an agricultural site, yet the following year they had disappeared although there had been no management changes.

A very charming and worthwhile addition to Moor Green Lakes Nature Reserve. Let’s hope they are still there next year.

[Previous Year]       [Previous Section]       [Contents List]       [Next Section]         [Next Year]

CHAPTER 10

REPORT ON NESTBOXES 2006

Dr K B Briggs

During February and March 2006 more wooden nestboxes were replaced by woodcrete boxes, two Stock Dove boxes and 5 tit boxes were sited on the new workings and 3 old Mandarin boxes replaced. A total of 50 boxes were on site and 94% were occupied in the 2006 breeding season. 

Great Tit

Egg laying was much delayed this year with the first egg on 15 April and 3 other pairs initiating clutches within 4 days. The majority of pairs laying in late April with a mean date of 22 April (sd 4.4 days). Laying proceeded normally with a mean clutch size of 8.4 (sd 1.4). However, during incubation hornets took over one box and weasels predated females and complete clutches of five incubating pairs. The probable reason for this was the lack of field voles widely reported in the country, but unfortunately the predator-proof woodcrete boxes failed in their primary task. Hatching success was good with successful birds having broods of 7.8 (sd 2.0) young and fledging broods of 7.5 (sd 2.1). Because of predation the 19 pairs that attempted to nest only had a 61% success in converting eggs to fledged young and averaged 5.2 (sd 3.9) young. This was a poor year. 

Blue Tit

Nine pairs used the nestboxes this year, the other 16 pairs on the reserve using natural sites or bat boxes. The first egg was laid on 17 April but most pairs waited about a week and the mean laying date was 23 April (sd 6 days). Mean clutch size was slightly smaller than usual, 10.5 (sd 1.7), and mean brood size on hatching was 10.0 (sd 2.0) and unusually no young were lost up to fledging giving a mean brood size of 10 young. Predation by weasels on two nest boxes during incubation reduced the overall conversion of eggs to young to 74% and the mean brood size at fledging to 5.2 (sd 3.9) young per nesting attempt. A poor year for this species.

Stock Dove

The first clutch was laid on 8 March but the two young died (aged about 2 weeks due to starvation) in late April. In total seven pairs nested in boxes but had very poor success due to nest usurping by Mandarins and chick starvation. Mean laying date for first clutches was 15 April (sd 17 days) and from 16 eggs laid, 10 hatched and only 4 chicks fledged. The 25% fledging success means this was the worst year recorded.

Mandarin

Ten nesting attempts were recorded in the boxes with the first egg laid on 6 April, a month later than 2005. Most females laid in the last week of April but two clutches were initiated in late May and could have been new females or relays after desertion. The mean laying date was 24 April (sd 19 days) and mean clutch size 11.4 (sd 6.5) with only three cases of egg-dumping recorded in clutches of 17,18 and 22 eggs. Grey Squirrels usurped 5 nests so overall breeding success was low. The five successful females had mean broods of 10.8 (sd 4.4) on hatching and 9.8 (sd 2.5) on leaving the nestbox. The 5-year old female FC77988 was unsuccessful in 2006, the clutch of 22 eggs she incubated being eventually taken over by squirrels. In total 114 eggs produced 49 duckling (43% success), making this a poor breeding season.

[Previous Year]       [Previous Section]       [Contents List]       [Next Section]         [Next Year]

CHAPTER 11

BUMBLEBEE SURVEYS DURING 2006

Steve Farmer

 Results of Bumblebee Surveys

Surveys of bumblebees were conducted at three sites on the Moor Green Lakes Nature Reserve during the summer of 2006. These were the wildflower meadows on (a) the west side and (b) the north side of Colebrook Lake North and (c) the small area of wildflower meadow on the north side of Grove Lake (near Grove Island). Surveys were also carried out at a fourth site. This was (d) the bank on the north side of Horseshoe Lake. Subsequently these are referred to as CLN (west), CLN (north), Grove (north) and Horseshoe (north) respectively.

These are all open sites with a range of different species of wildflowers, some of which were sown during the restoration of the gravel pits. CLN (west) has a good selection of species of flowers which thrive because of its low-lying position near the edge of the lake. CLN (north) is the largest area surveyed. It also has a good range of species. Some parts of this site are damp near the margins of the lake but other parts are very well drained and dry. Grove (north) has coarser vegetation and some of the finer species of wildflower are in short supply or absent. Horseshoe (north) is a steep dry bank. This has the poorest range of wildflowers and suffered the worst effects due to drought conditions during the summer of 2006.

The primary purpose of these surveys was to establish what species of bumblebees were present on the Moor Green Lakes Nature Reserve. Each survey was conducted by walking slowly across the site and making a note of all the bumblebees which were seen and could be confidently identified. A note was also made of the caste (queen, worker (infertile female) or male). In addition the type of flower which was being foraged and whether the bumblebee was collecting nectar or pollen or both. Any other interesting activity such as males “patrolling a scenting circuit” or nest sites were noted. The time taken for each survey at each site varied between about 20 and 60 minutes depending on the amount of bumblebee activity and the size of the site. No attempt has been made to normalise the number of bees seen to a standard observing pattern. The results reported here are all field observations. No bees were caught for examination off site.

The surveys showed that all of the six commonest social bumblebees were present on the sites. In addition one of the commonest “cuckoo” (parasitic) bumblebees was observed. These findings are in agreement with the maps of the distribution of these bumblebees published by the Bees, Wasps and Ants Recording Society (BWARS) for this area.

Three complete surveys were conducted. These were Survey A (21-22 June), Survey B (2-4 July) and Survey C (17-18 July). The surveys were made on fine, warm, sunny days. They were usually made during the morning when nectar flow is at a peak. During the summer of 2006 there was no problem with selecting two or three day periods of settled conditions. The numbers of bumblebees seen on each site on the survey days are given in Table 1, 2 and 3 below. 

A simple measure of the success of each site can be obtained by combining the totals for all the surveys. CLN (north) had the largest number of bumblebees recorded (l99),  followed by CLN (west) with (129). Grove (north) had (105) while Horseshoe (north) had only (57). CLN (north) appears to have been the best site but it should be stressed that it was also the largest site surveyed. There appears to be little doubt that Horseshoe (north) provided the poorest opportunities for bumblebees to forage.

A short summary follows for each of the 7 species of bumblebee recorded during the surveys.

Bombus pascuorum. (Common Carder Bumblebee).

The queens of this species emerge fairly early in the spring from hibernation. B.pascuorum has a long nesting cycle and the number of workers only build up slowly. The results of the surveys confirm this. It is surface nesting, typically among thick tussocks of grass. Some nests may have failed during the summer of 2006 due to the very hot, dry conditions.

Bombus lapidarius. (Red-tailed Bumblebee).

This species emerges fairly late from hibernation. It has a long nesting cycle and the number of workers builds up only slowly. The observations at MGL confirm the slow increase in the number of workers.

Bombus pratorum. (Early-nesting Bumblebee).

This species builds its nest early and has a short nesting cycle. By late June the nests were already declining. Only one new queen and one male were seen on 21 June and just a single male on 17 July. However this bumblebee is common in the suburban gardens in the Blackwater Valley in spring and its low incidence at MOL is not a particular cause for concern.

Bombus terrestris. (Buff-tailed Bumblebee).

This species is one of the first to emerge from hibernation and has a long period of activity, even having a second complete nesting cycle in some summers. The observations at MGL suggested a peak in the number of workers in early July. However some of the workers may have moved to alternative sources of nectar, perhaps in local gardens.

Bombus lucorum. (White-tailed Bumblebee).

This species emerges from hibernation early and the number of workers builds up throughout June and July until a large colony has been produced. The observations at MGL showed the number of workers increasing till mid-July.

Bombus hortorum. (Garden Bumblebee).

This species has a short nesting cycle. Observations at MGL Reserve show a peak in the number of workers in early July with a rapid decline thereafter. The first two male B.hortorum were seen on 18 July.

Bombus vestalis. (formerly known as Psithyrus vestalis). (No common name).

This is a “cuckoo” bumblebee that is parasitic in the nests of B.terrestris. After emerging from hibernation the female B.vestalis enters a well-established nest of B.terrestris and lays her own eggs. The host workers feed the larvae of the invader. Eventually new females and males of B.vestalis emerge and the nest declines due to the lack of workers. At MGL the first two male B.vestalis were observed in mid July.

Bumblebee preferences for wildflowers

The results of the surveys were analysed to establish which of the flowers growing on the Reserve were the most important for the bumblebees. Bumblebees are versatile feeders and forage on a wide range of flowers both in the wild and in our gardens. They also have to be ready to adapt as different plants come into full flower and then pass their peak. It was noticeable at MGL during the summer of 2006 that the types of flower that were abundant at any stage changed rapidly as the season progressed due to the hot weather.

Table 4 shows the number of each species of bumblebee seen foraging on different types of wildflower. These are the results for all surveys combined. The bumblebees were recorded on 16 kinds of wildflower, but most were observed on just 7 species which were available during June and July.

B. pascuorum was found mainly on Red Clover in June and Betony and Black Knapweed in July. B.lapidarius was found mainly on black knapweed in July. B.terrestris and B.lucorum were found mainly on St John’s Wort in June and early July, moving on to Blackberry and Black Knapweed later in July. B.hortorum, which has a very long tongue, was found on red clover in June and betony in July. Interestingly no bumblebees at all were seen on Ox-eyed Daisy and Yarrow, both of which are plentiful on the reserve. Yellow Loosestrife and Purple Loosestrife on the edge of the lake were not surveyed.