No. 2 April 1997
Worcestershire Record No. 2 April 1997 p. 4
CRAYFISH IN WORCESTERSHIRE
By Mike Averill
The Native
Only one native species of crayfish is found in UK waterways – the White-clawed Crayfish Austropotamobius pallipes. Unfortunately since the 1970’s other species of non-native crayfish have found their way into our rivers and streams and the consequences have been grave for the natives.
The White-clawed Crayfish is widespread in the British Isles but absent from Scotland, west Wales, and SW England, and it is generally tends to be confined to hard alkaline waters. It prefers streams and rivers with small amounts of sediment and does not tolerate pollution or anything that depletes oxygen levels.
Crayfish look like small lobsters, measure up to 15 cm long, and are greenish-brown in colour. Crayfish feed on animal and vegetable matter, usually at night, and they are eaten in turn by a range of fish, eels, birds and mammals, including rats, otters and mink. They can form an important part of an otters diet.
Mating takes place in October or November and when the eggs are laid they are attached to the underside of the female’s tail. Over-wintering as eggs the young hatch in the spring. The young cling to their mother and do not leave her until May or June. Generally the females have smaller claws than males but have wider abdomens because of the need to carry their offspring.
In Worcestershire nearly all crayfish records submitted to the Biological Records Centre have come from the Dowles Brook and its tributaries in the Wyre Forest. There are records from two other sites located at Malvern and Alvechurch. These records give a misleading view of local distribution because, compared with other sites, Dowles Brook has always been well-visited by recorders, and crayfish almost certainly are, or have been, present at other sites, particularly in the west of the county.
The Foreigners
At the moment there are at least four non-native crayfish to be found in Britain. The most common of these is the American Signal Crayfish (Pacifastacus leniusculus) which arrived in our countryside by being deliberately or accidentally released from fish farms. Also found but less widespread are the Turkish (Astacus leptodactylus) and Noble Crayfish (Astacus astacus). The Signal Crayfish was first farmed in 1976 and many soon escaped and it spread rapidly. One of the original reasons for introducing the Signal Crayfish into Europe was because it has similar characteristics to the Noble Crayfish which was only found on the continent. However, the former is a carrier of a fungal disease called Aphanomyces astaci and this has caused great mortality of both White-clawed and Noble Crayfish.
Our native crayfish was probably first affected in the late 1980’s and since then there have been a number of catastrophic killings in the Severn catchment alone. The first river to be affected was the Dowles Brook which had its population wiped out in 1988. Later, in 1990, the River Camlad had a major killing, followed by the River Clun in 1991. Not all Signal Crayfish carry the disease and some unaffected individuals have been found living alongside our native crayfish in the Dick Brook. Apart from the issue of the fungal disease the other problem causing pressure on our native crayfish is that they do not compete very well with the Signal Crayfish for habitat and food. When the Signal Crayfish do establish themselves they can be very difficult to remove. They can undermine banks by their deep burrowing and they also eat a large quantity of fish eggs. The fact that White-clawed Crayfish are absent from the River Rea suggests that the fungal plague is probably the cause.
The Law
In 1991 there were seven crayfish farms in the Severn catchment, three in the Severn including two near the Dowles brook, and four in the Avon catchment. As soon as the connection was made between the disease and Signal Crayfish, calls were made to restrict the farming of this species. Under the 1981 Wildlife and Countryside Act it is illegal to release non-native species without a licence, but it is extremely difficult to police this sort of activity. The 1983 Diseases of Fish Act states that all crayfish farms have to be registered with MAFF, but that is about the only action required of them.
Many conservationists foresaw the danger that farming introduced species would bring, but action was slow in coming and is, as usual, “after the horse has bolted”.
More recently, in May 1996, a statutory amendment to the Keeping of Live Fish (Crayfish) Order was made and certain restrictions now prevail:
- that there should be no non-native crayfish kept without a licence in England and Wales.
- Signal Crayfish, however, may be kept without a licence in areas outside those designated as a no-go areas by MAFF. These no-go areas occur north of a line from the Severn Estuary to the Wash but unfortunately do not include any of the Severn catchment because there have been a number of compromising outbreaks of plague here already. The Environment Agency (Midlands Region) is disappointed with this demarcation but is hoping that the Severn area can be used a buffer zone, and it would like the River Avon to be a no-go area because it has been plague-free to date.
- Existing crayfish farms in the no-go areas can continue for the time being. There are eight registered Signal Crayfish farms in the no-go area and about fifty outside this area.
Whilst it may be disappointing for the Severn catchment to be excluded from the no-go area it should be said that the exclusion zone was decided after consultation in 1994 with MAFF, the Joint Nature Conservation Committee, as well as farming and conservation bodies.
There are exemptions for hotels and restaurants and fish markets which are keeping crayfish for direct human consumption, however they are still bound by the rules concerning the release of foreign crayfish, and the rules stating that crayfish need to be kept in secure conditions. What is disappointing is the fact that Signal Crayfish farms do not have to be licensed outside the so-called no-go areas. The only restriction outside the no-go areas occurs for new farms who use open ponds and channels. The release to these would be deemed as the “wild” under the Wildlife and Countryside Act. Presumably purpose built tanks in the countryside would not be called “wild”! This is bad news for any attempt to try and reduce the spread of the disease in these areas. Crayfish are master escape artists and this is reflected in the rigid code of practice regarding transportation. Once the disease has got a hold in an area there does not seem any way to save existing native stock which quickly succumb. As long as infected Signal Crayfish exist in the waterway there is no point in re-introducing the native species and in any case the Signal Crayfish appear robust enough to settle quite happily in our waters.
The Present Situation
So what is the current situation with the plague? Spores from the fungus can be carried by damp equipment as well as by water, fish, animals and birds, however, the Signal and native crayfish appear to be the only hosts of the disease. It is obviously very important to maintain hygiene with respect to fishing activities in contaminated waters. Any infected crayfish should be reported to the Environment Agency or to MAFF.
Crayfish Records Wanted
The Worcestershire Biological Records Centre is keen to have details of any old or new crayfish records. To help with identification the following key should be useful. Although four species of crayfish have been mentioned in this article it is unlikely that anything other than the White-clawed and the Signal would be encountered in Worcestershire.
White-clawed Crayfish
Up to 10 cm long. Rostrum (platform between eyes) converging forwards. One post orbital ridge behind each eye. Median ridge of rostrum smooth or absent. Colour olive/dark brown Claws rough on top, narrow compared to Signal crayfish.
Signal Crayfish
Up to 15 cm in length. Rostrum nearly parallel sided. Two post orbital ridges behind each eye. Median ridge distinct, often toothed. Bluish/brown to reddish/brown in colour. Robust large smooth claws. White patch near claw hinge
Records of either crayfish would be very welcome as a constant watch needs to be kept on this developing situation. Once again we are witnessing the dramatic effects of an introduced species on the balance of our wildlife.
Please send records to John Meiklejohn, Worcestershire Biological Records Centre, Worcestershire Wildlife Trust, Lower Smite Farm, Hindlip, Worcester. Older records would be welcome if you are sure of identification and have a reasonable fix on the locality.
Reference
Holdich, D (1991) The native crayfish and threats to its existence. British Wildlife 2, (1), 141-151. This article provides a good summary of the situation, which has since deteriorated as far as the native is concerned. There are also photographs and diagrams to aid identification, and a good reference list. There have been changes in the law, as outlined above, since Holdich’s article was written.
Worcestershire Record No. 2 April 1997 p. 4
GOMPHUS VULGATISSIMUS – OVERLOOKED OR ALWAYS THERE?
by Mike Averill
The Club-tailed Dragonfly (Gomphus vulgatissimus) is a nationally scarce dragonfly being the 13th rarest dragonfly in the British Isles. In Worcestershire it is found in 14 10km squares, 65 tetrads and 148 monads which probably makes the county the most important in the country for this species. Only Oxfordshire can claim as many 10km square records but Worcestershire has a much greater density of records in terms of monad records. This is a big responsibility to carry and it means that river habitat and water quality in the county must be protected and maintained.
The question is, was this county always as important as it is today? That is difficult to answer because the records are rather patchy for years prior to the 1980’s.
Club-tailed records have been taken on the River Severn since the beginning of the century when J E Fletcher reviewed the insects of County in the Victoria County History. They have been recorded ever since and in the most recent survey they have been found in every 1 km square along the Severn. It seems then that the Severn has always been a stronghold. What is puzzling is the more recent noting of this species on the Rivers Teme and Avon. The first records close to the River Teme came in 1977 and near the River Avon in 1978, both of these sightings being made by Tony. Simpson. Since then there were many records made in the eighties and there is not much doubt that both rivers are quite important in their own right for this dragonfly. Could this be a comparatively recent development or was this species just overlooked ……. please let me know if you have any older records or any anecdotal information about these rivers.
It would also be useful to try and put some detail on the relative abundance of the Club-tailed Dragonfly on the Rivers Avon and Teme. Could anyone help with a census on these rivers? This would take place in mid May to mid June.
Worcestershire Record No. 2 April 1997 p.8
TERRESTRIAL (LAND) CADDIS
G H Green
Worcestershire’s Land Caddis Enoicyla pusilla are quite well-known from the writings of the late Norman Hickin. During a February 1997 foray with Brett Westwood into the countryside north of Kidderminster I collected a few bags of woodland leaf litter to search for invertebrates. Within one of these David Green found a Land Caddis about 5 mms long. This prompted me to write this note and to appeal to recorders to look for the species in Worcestershire’s woods so that we can determine its actual distribution. In Wyre Forest area it is also worth looking in Shropshire and Staffordshire!
To find Land Caddis larvae it is best to examine woodland leaf litter and moss on site. Probably best to look between March and June when the larval cases are maximum size about 7-10 mms long and 1-2 mm diam. Shake the litter over a white sheet and examine carefully. After examination return the litter and the caddis to the woodland floor.
The larvae and pupae of most Caddis flies, Trichoptera, are, of course, aquatic. Many species make cases to enclose larvae and pupae. Others spin webs in water to catch debris or tiny invertebrates.
According to Hickin between 1868 and 1879 McLachlan and Fletcher first found Land Caddis near the city of Worcester. From that date until 22nd April 1957 it had not been recorded in Worcestershire until Norman Hickin found them in the Wyre Forest (Hickin 1967). Fletcher (1901) in The Victoria County History of Worcestershire states that Terrestrial Caddis has probably not been found in Britain outside Worcestershire and as a site gives “by a rill, Little Eastbury” In recent times the species has been found occasionally in other woods in and around Wyre Forest, and near Worcester in Nunnery Wood and Monkwood. One hears indistinctly on the grapevine that it has been found in a few other woods but there are no records in the BRC.
Where is Little Eastbury? Using the “Place-names of Worcestershire” and an OS map I found such a place near Hallow. But is this the correct location and where is the rill?
In a recent review (Wallace 1991) the species is designated RDB3 (Red Data Book 3) which means “locally common”. For this species this means that it is only found in parts of Worcestershire and no-where else in Britain. Apparently it is known mainly from “greater Wyre Forest” – the forest and surrounding woods.
The species has a patchy continental distribution and knowledge of its biology comes from Europe.
The species is unique in British Trichoptera is having terrestrial larvae and pupae, and a wingless adult female, and worldwide the genus is unique is having these features.
According to Hickin, who reported European studies, the adults emerge during September to November. The females cannot fly and live for about five days. The males live a couple of weeks. The eggs are laid shortly after mating and hatch in about three weeks. The tiny larvae immediately start to construct a curved protective case which is about 1.5 mm long at the end of the first day and by the following June is about 10 mms long and little over 1 mm diameter. The case is made of tiny fragments of dead leaf and sand grains. The larvae feed on softer tissues of dead leaves, especially oak, mosses and algae, as they move around within woodland ground litter. When full-grown they burrow down, close the case with silk, and pupate for about a month.
References
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Fletcher JE (1901) Trichoptera in Victoria History of the counties of England – Worcestershire. Volume one. Constable. |
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Hickin, NE (1967) Caddis Larvae. Hutchinson |
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Mawer, A, Stenton, FM & Houghton, FTS (1969) The Place-names of Worcestershire. Cambridge University Press. |
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Wallace, ID (1991) A review of Trichoptera in Great Britain. Research and survey in Nature Conservation No 32. Nature Conservancy Council, Peterborough |
Worcestershire Record No. 2 April 1997 p. 8
THE ENIGMATIC MOLE CRICKET LIVES ON
By Howard Inns
The Mole Cricket, Gryllotalpa gryllotalpa is one of the insects targeted by English Nature’s Species Recovery Programme. Once common enough to be regarded as a pest in parts of the country, in the last 50 years very few Mole Crickets have been seen on the UK mainland, most reports being of single specimens from the southern counties. The species can still be found on Guernsey. The primary objective of the Species Recovery project has been to determine whether or not the species is extinct. The team of naturalists working on the project are happy to report that the species was present on one small privately owned site in north west England in both 1995 and 1996.
The team have appealed for information via radio and television broadcasts, local newspapers and poster campaigns in likely areas and via the gardening press (several of the most recent reports have been from gardeners finding the insect whilst digging). Several promising reports will be followed up in 1997.
This year, the team is also appealing to other naturalists to report any Mole Cricket sightings, however long ago. The aim is to find any extant colonies in order to confirm the general habitat requirements, to protect and enhance any sites found and review the viability of a captive breeding and re-introduction programme.
The Mole Cricket spends the majority of its life underground, burrowing up to 2 feet (60cm) below the surface. It is a large, powerful and unmistakable insect with big spade like front legs and a heavily armoured thorax, perfectly designed for digging. Adults measure approx 1.5 inches (4cm) in length and are normally chestnut brown in colour. Male Mole Crickets can sing although they do not do so as habitually as other orthopteran species . The song is a single continuous and penetrating note, normally heard from dusk until the early hours on warm evenings in May and June. It can be confused with the slightly lower pitched ‘reeling’ song of a Grasshopper Warbler. The female Mole Cricket constructs a hen’s egg-sized underground nesting chamber in mid summer in which she lays her eggs which she tends by licking them until they hatch a month or so later. The young nymphs take at least a year to become adult.
The ideal sites are damp waterside meadows rising to dryer ground with a relatively short or grazed sward on light or sandy soils. Gardens, allotments, golf courses or pond margins with similar characteristics are also potential sites. Individual animals are only likely to be found as a result of being dug up, by hearing their song or by turning debris (such as old planks of wood) exposed to the sun. There is evidence to suggest they are attracted to recently disturbed soil and they are known to be attracted to light.
If anyone knows of any old records, or obtains new ones, please let John Meiklejohn know at the Worcs BRC.
Worcestershire Record No. 2 April 1997 p. 1 This article is outdated and remains for Archive purposes only
THE DEVELOPMENT OF THE WORCESTERSHIRE BIOLOGICAL RECORDS CENTRE – WHERE ARE WE NOW?
by G H Trevis, Chairman Worcestershire Wildlife Trust’s Wider Countryside Committee.
We were recently informed that the consortium bid to the Millennium Fund for the establishment of a national network of records centres has been unsuccessful. Clearly this is a great disappointment since without the substantial funding which the bid offered it will be harder to achieve the goal of a growing data base of high quality records. However, the consortium will continue to seek funds from other sources and in the meantime we should not let the absence of external funding stop us from continuing our own local initiatives.
Our objectives remain unaltered. We will be establishing a computerised records system to provide information to a wide range of users including conservation organisations, local authorities, planners and the general public. We will also be analysing and in some cases publishing data to assist with biodiversity planning and the implementation of strategies and to assess the state of Worcestershire’s wildlife with a view to drawing up a “Red Data Book” for the county.
In March last year we had the first recorders meeting at which we launched the new initiative and over the twelve months since then there has been very considerable progress not least in the increasing flow of records to John Meiklejohn at the present centre. Our thanks for this and please keep the records coming – while the seven-spot ladybird seems to be a rarity noted only in two or three tetrads there is clearly much to do!
A brief audit of the records reveals the not unexpected finding that the drawers for birds, butterflies and flowering plants are reasonably well filled whilst those for mites, weevils or hymenoptera remain woefully small. The series of introductory courses on some of these less well known groups was started to try to redress the balance and it pleasing to note that all have fully booked. We hope now that specialist groups will be established to maintain interest and plan recording. Information about the first of these appears elsewhere in this edition of The Record. Further courses will be arranged.
Many Trust members answered the questionnaire about their interest in recording and we have again been delighted at the large response. I hope those who did return their form will forgive the slow response but it is taking time to analyse the data and draw up plans based on the needs which that reveals. Courses will be organised and for those wishing to undertake recording on their local reserve the necessary contacts will be made – just give us a little more time!
The Records Centre itself was set up, in a far sighted move, by Worcester City Council originally with the help of the Manpower Services Commission. Since then, through all its various moves, it has remained under the City Council’s Arts, Museums and Archaeology Sub-committee. Now that it has arrived at Lower Smite Farm we felt we could not make sweeping changes and commit significant resources without first getting the agreement of Worcester City Council to the Trust taking over long term management. Colin Raven and I were given opportunity to present our proposals to the Sub-committee and I am glad to say that we received their enthusiastic support. We will, of course, be keeping them fully briefed and involved in the developments which we can now undertake.
The first major development is computerisation to make the records more easily accessible and to provide the means for analysis and mapping. The Trust has purchased a number of copies of the “Recorder” software and our computer group is working on implementation. There is a lot of work to be done before we begin the serious business of entering the existing records but a good start has been made. We will up date you at the May recorders meeting.
A successful records centre depends heavily on good working relationships between those who submit records and those who may wish to use them. Recorders have copyright and intellectual property rights in respect of the records they submit and quite rightly would not wish to see these rights infringed by inappropriate publication of their work or by unethical use by users of the service. It is essential therefore that the ground rules for running the centre and the management structure are agreed and accepted by all those involved. The first part of the recorders meeting in May is, therefore, devoted to a discussion of these issues which we hope will lead to the formation of a management group composed of users and recorders. More details will be given nearer the time.
Finally, Harry Green and I were able to visit the natural history collections at the Worcester City Museum with the Curator, Garston Phillips. The amount of material there is frankly mind numbing as one views case after case of butterflies, moths, hymenoptera, herbarium specimens etc. often with the names of the great Worcestershire naturalists attached. We hope to make far more use of these collections, by agreement with Mr. Phillips, since they have huge potential for giving base-line data about the county and in helping the more advanced recorders to develop their identification skills. At the same time the attention of more expert people would help the museum in the cataloguing and maintenance of the collections. Development of such partnerships between all concerned with the Worcestershire’s wildlife can be nothing but beneficial.
A year ago I felt immensely optimistic about the future of recording in the county and, despite the failure of the Millennium bid, I feel no less optimistic now. We have made a great start and provided we maintain the effort the benefits for the conservation of wildlife in Worcestershire will be commensurately great. We recognised that the national commitment to biodiversity is the most important step forward in conservation since the Wildlife and Countryside Act. That remains true and knowledge of the diversity of wildlife in our area is the key to successful implementation.
Worcestershire Record No. 2 April 1997 p. 6
THE HYMENOPTERA
G H Trevis
The Hymenoptera is a huge group comprising a large percentage of the total insect population of Great Britain (about 6,500 species out of about 23,000 species of insect). Defining what is meant by “hymenoptera” is not easy and perhaps the most comprehensive if unintelligible definition I have come across is “The hymenoptera are haplo-diploid, holometabolous insects which have biting mouth parts, but which lack elytra”. Certainly these are matters which we will all be able to check out in the field! They are, of course, the bees, wasps, ants, sawflies and wood wasps, which share the observable features of biting mouthparts; two pairs of membranous wings, the larger forewings and the smaller hind wings linked by one or more small hooks; female ovipositor generally present; and antennae prominent, generally with n@me or more segments.
There are about 6,500 species of hymenoptera recorded in Great Britain which range from the well known social wasps and bees to obscure parasitic species recorded perhaps only once by an academic expert in the field, and who is probably the only person in the country who could identify the insect. The first stage of their classification is into two groups, thesymphyta and the apocrita. The symphyta are the sawflies and wood wasps and the apocrita are the species having the typical “wasp waist”. The apocrita are again subdivided into two groups, the parasitica and the aculeata. As their name suggests the parasitica are species which have adopted a variety of parasitic ways of life, the majority of them being so little studied as to be virtually unknown. The aculeata are the species in which the female ovipositor has been modified to form a sting and which include the familiar social bees and wasps. At the latest count, the symphyta comprise about 470 species, the parasitica about 5,500 species and the aculeata some 74 species of social bees, ants and wasps, about 217 species of solitary wasp and about 226 species of solitary bees (Archer, 1996).
The present status of the Hymenoptera generally is probably largely unknown. Archer notes 125 Red Data Book species (53 solitary wasps and 72 solitary bees), of which 31 may well be already extinct, plus a further 91 species designated nationally scarce. The Red Data Book also records two endangered wood ants, Formica pratensis and Formica transkaucasica. A further source of information is “Biodiversity: The U.K. Steering Group Report”. On the short list are three ants, Formica candica (transkaucasica), Formica exsecta and Formica pratensis plus the Shrill Carder Bee, Bombus sylvarum. The middle list adds one ant, Formica rufibarbis and nine bees – Andrena floricola, Andrena gravida, Andrena lathyri, Andrena lepida, Bombus distinguendus, Bombus humilis, Bombus ruderatus, Bombus subterraneus and Osmia xanthomalana. Finally, the long list includes the bees Anthophora retusa, Colletes cunicularis, Lasioglossum angusticeps, Lasioglossum pauperatum, Lasioglossum sexnotatum, Nomada errans, Nomada sexfasciata, Osmia inermis and Psithyrus rupestris plus the wasps Chrysis pseudobrevitarsis, Crossocerus vagabundus, Homonotus sanguinolentus, Miscophus ater, Odynerus simillimus, Pemphredon enslini and Pseudopipona herrichii. However, considering the number of species in Britain the above list probably represents and underestimate.
When it comes to the parasitic wasps the situation is hopeless and the Red Data Book lists no species at all. It comments: “Although accounting for about a quarter of our insect fauna, the parasitic Hymenoptera are among the least understood insects in Britain and, at a time when the ecology – and indeed taxonomy – of so many remains obscure, it is difficult to single out the species and groups whose populations are most at risk” and “Many parasitic Hymenoptera have been collected on only one or two occasions in Britain but, in view of our ignorance of their origins and host associations and the paucity of collectors, it is probably advisable to ignore all these as candidate species until ecological knowledge enables surveys to made with respect to their host populations”.
Why are the solitary species under threat? Five major reasons have been listed by Else, Felton and Stubbs (1978):
- Solitary bees have a low reproductive rate of about 8-12 per generation with many producing only one generation per year.
- Each species has a complex mixture of resource requirements e.g. bare dry soil or dead wood in a sunny sheltered situation for nesting and a nearby habitat with flowers for food and prey.
- As traditional countryside disappears, species have become increasingly restricted to habitats which are not undergoing intensive agriculture. Unfortunately, these habitats are being lost.
- Most species have limited powers of dispersal so that, as suitable habitats become fragmented, re-colonisation of isolated patches becomes less likely.
- Many species require sunny, sheltered, bare ground or dead wood for nesting, which is usually found in disturbed and neglected habitats e.g. crumbling soft rock cliffs, eroding river banks, disused quarries, bramble patches and lying or vertical dead wood. The growth of vegetation, stabilisation of river banks and the tidying-up and removal of bramble and dead wood eliminates these habitats.
The importance of the Hymenoptera lies in their value in habitat assessment. Whilst most of the common social species are too ubiquitous and the parasitica too little known to be of help in this regard, many of the remaining solitary aculeates provide useful indicators. The reason for this is clearly evident from the list of the causes of their decline given above. The specialisation of their requirements for the different aspects of their lives means that a rich assemblage of solitary aculeates equates with a rich and varied habitat. Archer (1996) has studied the relationship between the number of species on a site and the quality of the habitat. His method involves giving each species a status value ranging from 1 for universally common species to 32 for Red Data Book species. For any site the sum of the status values for the species present will give a quality score whilst dividing this by the number of species will give a species quality score. In this way quantitative results can be used for site comparison.
Robinson (1997) provides an interesting illustration of how a common but varied habitat can provide for these insects. A study in his garden, which he describes as “20 years old, on a modern estate and of typical suburban lay-out”, found six species of bumble bee, one cuckoo bee and thirteen species of solitary bee. The garden is in a village surrounded by permanent pasture. The report goes on “The attraction of the garden is clearly as a pollen and nectar source. In this respect Natland stands out as an island of floristic diversity in a uniformly green landscape, thin hedges and stone walls. The only other places of any value for solitary bees which I have been able to discover in the vicinity are a few stretches of roadside verge and some slopes beside the river which are too steep for the farmer to improve”.
In the Worcestershire Biological Record Centre the hymenoptera records are few and far between except for the systematic work of Dr Michael Archer, mainly at Devil’s Spittleful and Rifle Range. Dr. Archer has been visiting regularly from the University College of Ripon & York St John to record the solitary bees and wasps. His latest report of visits made in July and August 1996 says “I have been able to add a further six species to give an unofficial list of 121 species”. This is an impressive total which underlines the importance of heathland habitat for many species of the group. An interesting task, with Michael Archer’s permission, would be to analyse the data using his quality and species quality methods.
There is a great deal of work to be done on recording Worcestershire’s Hymenoptera and any information on the group as a whole will be welcome. Even common species of social bees and wasps are virtually unrecorded so that a little effort with these will pay dividends. Perhaps one day we can arrange an introductory course on identification and start a local recording group. Nationally there is a Bees, Wasps and Ants Group and it would be a great step forward if we could begin to contribute to its work and gain insight into the status of these fascinating insects in our county.
References
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Archer M (1996) in Environmental Monitoring, Surveillance and Conservation Using Invertebrates. Ed. M.D. Eyre, EMS Publications. |
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Else, G., Felton J. & Stubbs A (1978). The Conservation of Bees and Wasps. Nature Conservancy Council, Peterborough. |
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Gauld, I & Boulton, B (eds) (1996). The Hymenoptera. OUP. |
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Betts, C (ed) (1986) The Hymenopterists Handbook. Second edition. Amateur Entomologists Society. |
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Shirt, DB (ed) (1987) British Red Data Books: 2 Insects. Nature Conservancy Council. |
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Biodiversity: The U.K. Steering Group Report Volume 2, HMSO 1995. [the long list is given at the end of this newsletter – ed] |
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Robinson, N. (1987) Solitary bees in my garden, Bulletin of the Amateur Entomologists Society, Volume 56, Feb. 1997. |
also further information in:
Falk, S (1991) A review of the scarce and threatened bees, wasps and ants of Great Britain. Research & survey in nature conservation no. 35. Nature Conservancy Council, Peterborough.
Worcestershire Record No. 2 April 1997 p. 3
A ROUGH GUIDE TO THE STATUS OF AMPHIBIANS IN WORCESTERSHIRE (1997)
By Will Watson, Coordinator of WRAG The Worcestershire Reptile & Amphibian Group
In Worcestershire we have five of the six species of native amphibians; these are the common frog, toad, great-crested, smooth and palmate newts. The natterjack toad has long been extinct within the county.
The rarest of our county’s amphibians is the palmate newt. Nationally it tends to be confined to ponds with low nutrient levels and is the only species of newt capable of tolerating low pH conditions associated with acidic rock formations. Its county strongholds are within the Wyre Forest and near the Malvern Hills. Other unconfirmed reports of palmate newt have come from the Knapp and Papermill Reserve, Hartlebury Common and the Chadwick Estate.
The great-crested newt is specially protected under the Wildlife & Countryside Act because England and Wales is the international centre of distribution for this species. Nationally this species has been in steady decline because of the losses of country ponds and their general decline quality. However, they are still widely distributed within Worcestershire, although its density of occurrence varies according to geology and land-use patterns. All three species of newt cannot tolerate prolonged fish predation. Typically crested newts favour ponds which hold water throughout the summer months and are not densely shaded and silted. They also show a preference for moderately eutrophic ponds with a neutral to slightly basic pH. It is therefore not surprising to learn that, because of the water’s mild alkalinity, they are more commonly found in ponds on the Mercia Mudstone and Lower Lias clays in the county. A blanket pond study of the Warndon area of Worcester covering 4.2 square kilometres located 60 pond and wetland sites within this small area. Despite the fact that over half were shallow and ephemeral or heavily silted, great crested newts have now been located within 21 sites within this small area. It is probable that the great-crested newt is as common within other parts of the county which bear similarities to Warndon. More studies will have to be undertaken before we know the exact status of the great crested newt within the county. However, indications to date do suggest that Worcestershire ponds are particularly significant for great crested newt.
The smooth newt is the most common newt within the British Isles and within the county of Worcestershire. It is found in similar conditions to the great-crested newt, although it is better suited to smaller and ephemeral type ponds. It is also better at colonizing new sites than the above species. It readily colonizes garden ponds.
The common frog has declined within the rural landscape mainly due to pond losses, but has increased within urban areas due to people building garden ponds. Despite the changes in agriculture, the overall population trend for this species is up both nationally and locally.
Swapping of frog spawn may be partly responsible for this trend. However, the worrying spread of the viral disease known as ‘red leg’ is almost certainly encouraged by the swapping of frog spawn. To date there have been few reported incidents of this disease in the county, but as a precaution people are advised not to translocate frog spawn. Recent results from the Wyre Forest indicate that there has been a steady decline of frogs over a 10 year period, so far the reasons for this decline have not been explained. Low frog recruitment has also been noted from other ponds on acidic ground in the west midlands.
The common toad is also broadly distributed within the county. Once established within a breeding site a sizable colony of toads develops. Where conditions are right thousands of toads may use a particular breeding site. They may disperse a mile or more from their breeding pond to seek out new feeding grounds. There is a tendency therefore for distribution to be clustered around important breeding sites with apparently suitable areas absent of toads. A massive colony of toads exists at private pools at Church Lench, this site is known to support over 10,000 breeding individuals. The author has also been informed of other large colonies in the area. Large populations of toads (and indeed other amphibians) can only develop if terrestrial conditions are suitable. In order for toads to over-winter successfully they must find frost free conditions. Soil and geology is particularly important. One can only assume that the fertile soils of around Church Lench are ideal in this respect.
Although the natterjack toad is now extinct within most inland counties a recent record came to light to show that it may have been present within Worcestershire in the 19th Century. A party from the Worcestershire Naturalists Club found what they describe as “an uncommon Batrachian the natterjack toad” between Hanbury and Piper’s Hill Common.
Worcestershire Record No. 2 April 1997 p. 3
A ROUGH GUIDE TO THE STATUS OF REPTILES IN WORCESTERSHIRE (1997)
By Will Watson
There are six species of reptiles native to Britain; three snakes, the Grass Snake, Smooth Snake and the Adder and three lizards: the Common Lizard, Sand Lizard and Slow worm, the latter of which most of you will know is a lizard without legs; vestiges of these appendages are present beneath the skin.
There are four species of reptile present within the county. The Smooth Snake has never been recorded within the county. The Sand Lizard however, was present within the Wyre Forest during the last century and probably into the early part of this century. According to the Victoria County History other apparent sightings of Sand Lizard have come from Old Swinford, Tenbury and the Ragley Estate. There have been no confirmed sightings of Sand Lizard within the county this century, although I was informed by an gamekeeper (!) that large ‘green’ lizards had been seen on an estate to the north of Kidderminster.
Our rarest reptile is the Adder. This is not surprising since it has a preference for dry heathy habitats with a mixture of shrubs and open areas upon which to bask; such suitable locations are increasingly hard to find within the county. Well known Adder strongholds include the Wyre Forest and most of the Malvern Hills. Less well known sites include Kingsford Country Park and Kinver Edge (in Staffordshire), Habberley Valley and Arley Wood. Adders were previously present on the Lickey Hills, Storridge Common, Knapp and Papermill Reserve, Bredon Hill and at Wood Norton. However, there are no recent records from these five sites. Such smaller, often isolated populations are particularly vulnerable to habitat change and persecution. Evidence of the fragility of Adder population has been born out by Sylvia Sheldon’s detailed study of Adders in the Wyre Forest, which shows a 30% decline over a five year period with little movement of animals between sites. If you know of any Adder sites or have old records please do pass them on to Sylvia Sheldon or myself. Once we have a confirmed presence on a site we can take measures to conserve what is our rarest herptile. In particular, if you can obtain any records from less well-known sites this would be especially valuable. The Grass Snake is probably has the widest distribution of our reptiles. Its main food items are amphibians. It is therefore usually encountered close to freshwater habitats. Despite being regularly encountered across the county it is known to have declined both nationally and locally. This decline is reflected by the losses of good amphibian sites. It is none-the-less better at colonizing new and former sites. It is probable that Grass Snakes will be present within a mile radius of a wetland (ponds, lakes, marsh or other) that in most years support healthy population of frogs or newts. It is worth noting that the Grass Snake is particularly partial to Great Crested Newt tadpoles if it can catch hold of them!
The Common Lizard has a surprisingly local distribution within the county. Notable populations exist on Hartlebury Common, the Rifle Range and Devil’s Spittlefull Reserve, the Lickey Hills, the Malverns and the Wyre Forest. Recently they were also confirmed from Wilden Marsh, near Kidderminster and Tunnel Hill, near Evesham. There are undoubtedly several small isolated populations of Common Lizard within other suitable habitats. Indeed they will establish viable populations in areas of very small habitat such as old walls with crevices, dry south facing road verges and even suburban gardens. There must be more sites in the county for Common Lizard so please keep us informed.
The Slow-worm is relatively widespread within the county with some locations containing an abundance of the species but in other parts of the county it is apparently absent. In terms of shear numbers they are without a doubt our commonest reptile. They are typically found in areas of rough ground and are well suited to habitats containing tall herbs and grasses where it preys upon slugs, crickets, grasshoppers and young snails. They also like a compost heap in which to hibernate and give birth to their young. They will select discarded rubbish like a pieces of corrugated iron as a handy resting site. They are present in the Wyre Forest, Malvern Hills, Monkwood, Trench Wood and many other such undisturbed habitats. However, perhaps not surprisingly, they are far more abundant within urban situations than rural sites. A recent survey in Worcester found over 200 slow-worms on a 3ha semi-derelict allotment site, but none were found during a survey of another allotment site. Gardens and other urban habitats are more likely to satisfy Slow-worm requirements than rural sites. They probably occur in the majority of conurbation in the county, but so far we have very few records. If you know of any other such areas please pass on the information.
If any readers would like to participate in recording and researching Reptiles in 1997 we would be pleased to hear from them. And we need records!
Worcestershire Record No. 2 April 1997 p. 6
BUTTERFLIES FOR THE NEW MILLENIUM: THE BUTTERFLYNET PROJECT
Mike Williams of Butterfly Conservation wrote about this project in “Butterfly Bonanza” published in Worcestershire Wildlife News no 76 September 1996, and included a map showing a lot of gaps in butterfly recording in Worcestershire! Nick Greatorex-Davies, National Project Co-ordinator, now gives more information and appeals for your help.
A major project, Butterflies for the New Millennium, managed by Butterfly Conservation and the national Biological Records Centre at the Institute of Terrestrial Ecology, is the largest and most comprehensive survey of butterflies ever undertaken in the UK.
Wildlife Trusts, local record centres and many other groups throughout Britain and Ireland are collaborating to pool data through the ButterflyNet initiative, a network of local coordinators covering Britain and Ireland. This will be used to provide a detailed audit of the status of our butterflies, culminating in the production of an atlas in the year 2000, based mainly on recording between 1995 and 1999, but also using historical data. Recording will continue beyond 2000 to ensure the information is kept up-to-date.
Help with the project is warmly welcomed from everyone interested in butterflies. The success of Butterflies for the New Millennium depends upon individual butterfly recorders (you!) contributing to local recording projects, which will then feed into the national database. The data is being collated rapidly each year to give a national picture, and fed back to record centres. Feedback to recorders will be through their local coordinator.
Information from the database will be made available to support research and national and local action plans for threatened butterflies. The statistics on recent decline of some butterflies are very disturbing. The High Brown Fritillary, once common in woodlands in southern Britain, has declined by 94%, while the Marsh Fritillary’s range has contracted by over 60%. These changes reflect the widespread loss and damage to wildlife habitats, especially in the lowlands.
Butterflies, like most insects, must breed successfully every year if they are to survive. They are also very sensitive to habitat change. Many of our rarer species which do not fly great distances, are now so isolated that they are unable to re-colonise sites if they fail to breed one year, for whatever reason.
A few species are expanding their range northwards, for example the Small Skipper, Comma and Gatekeeper. Others are colonising new areas within their current range, these include the Brown Argus, Speckled Wood and Ringlet. The reasons for the changes are far from fully understood, but the Butterflies for the New Millennium will help shed some light on the causes.
The map is based on some of the data already received after the first two seasons of the project – there are many gaps still to be filled. You can contribute by noting down details of the butterflies you see at home, out and about in the local countryside or on holiday. Please send your records in at the end of the season, preferably to your local ButterflyNet coordinator, or to Butterfly Conservation, PO Box 444, Wareham, Dorset BH20 5YA. For an information pack, including instructions and special recording forms, please send a large (A4 – approx 9″x12″) stamped addressed envelope (31p) to Butterfly Conservation (Head Office), P.O. Box 222, Dedham, Colchester, Essex, C07 6DE. Every record counts and will help to make the national jigsaw picture complete! If you are not already a member of Butterfly Conservation please consider joining. The Society has a network of 30 regional branches which can give local assistance.