Gene flow ...

Arundel Wetlands

The beautiful water vole, Arvicola amphibius, was once a common site along the banks of the Arun Valley waterways. However, the modification of landscapes for agriculture and urbanisation, and the colonisation of the American mink, Neovison vison, led to their dramatic decline both locally and nationwide. In Sussex alone, we have sadly lost over 90% of our historic populations.

The Arun Valley water vole project is studying the gene flow within and between water vole populations, and investigating the effect of different habitats and landscapes in Sussex. The research is being undertaken during 2012 and 2013 and involves both field and laboratory techniques.

With the help of volunteers, numerous ditches were surveyed over a three month period, and evidence of breeding water voles was found on 13% of the waterways surveyed. This was an encouraging sign but, for the most part, only a few latrines were recorded. However, it was on an agricultural drainage ditch at Houghton Bridge, near Amberley, that signs of recolonisation were evident. Large concentrations of water vole latrines, feeding stations and burrows were present, indicating a potentially viable breeding population. This was great news as it suggested that water voles were recolonising northwards up the valley.

This raised several questions:

Had this newly found population come from Arundel Wildfowl & Wetlands Trust (AWWT), which is a reintroduction site located approximately 6.5km downstream?

Was the population too isolated and unable to rely on new individuals that would provide demographic and genetic rescue?

Can farmland ditches, not managed for water voles, hold viable populations?

Over the last two years Rowenna Baker has set out to answer these questions by studying the genetic structure and demographics of water voles at Houghton Bridge and AWWT through live trapping individuals each year, PIT (passive integrated transponder) Tagging, and by taking hair samples to obtain DNA for genetic mapping. Encouragingly, the abundance of water voles at Houghton Bridge is comparable to other natural colonies occurring along similar habitats nationwide, with estimates ranging from 20 to 50 individuals along 1km of bank. The population is small in comparison to  AWWT (135 individuals in 2010), where they are not affected by the external pressures of grazing and predation that commonly constrain habitat availability and density in unprotected sites. Both populations remain genetically diverse, however dispersal between populations is low, which is unsurprising as the average dispersal of water voles is 1-2km.

Despite the importance of genetic fitness, little is currently known about the genetic structure of water vole populations and what factors facilitate or impede gene flow within and between populations. Other studies have found that increasing distance between populations, land use and habitat design can all influence gene flow in animal populations.

The Arundel population is clearly a vital source for the recolonisation of water voles within the valley, however it is crucial that landscape connectivity is improved to aid dispersal between newly established populations. With additional colonies being found as far north as Pulborough Brooks, Rowenna now uses remote hair tubes to obtain genetic samples from all occupied sites in order to investigate gene flow and factors that facilitate and impede dispersal. This information will help to guide management to strengthen isolated populations by creating habitat networks that will hopefully promote water vole dispersal and recolonisation.

An important project regarding an excellent flagship species and one which I was privileged to witness first hand.

My thanks to Rowenna ...

Time for action ...

2012 was the worst year on record for UK butterflies.

We all knew it, but it's now official ...

"Washout 2012 was the worst year for UK butterflies on record with 52 out of the 56 species monitored suffering declines, a scientific study today revealed. Some of our rarest species, such as the fritillaries, bore the brunt of the second wettest year on record and now face the real threat of extinction in some parts of the UK.

Last year’s relentless rain and cold created disastrous conditions for summer species in particular as they struggled to find food, shelter and mating opportunities; butterfly abundance plummeted to a record low as a result and 13 species suffered their worst year on record. The critically endangered High Brown Fritillary fell by 46%, the vulnerable Marsh Fritillary was down 71% and the endangered Heath Fritillary saw its population plummet by 50% in comparison to 2011. Many of our most threatened butterflies were already in a state of long-term decline prior to the 2012 deluge. There are now real fears that these already struggling species could become extinct in some parts of the UK as a result of last year’s wet weather.

Hairstreaks did particularly badly last year - the Black Hairstreak, one of the UK’s rarest species, saw its population fall by 98%. The Green Hairstreak was down 68%, the White-letter Hairstreak fell by 72% and the Brown Hairstreak, slipped by 34%. Many common species also struggled. The Common Blue plummeted by 60%, the Brown Argus collapsed by 73% and the Large Skipper fell by 55%. The widespread ‘Whites’, including Green-veined White, Large White and Small White, saw their populations tumble by more than 50%. The Orange-tip fell by 34%. The alarming slide of garden favourite the Small Tortoiseshell continued, with its population slipping 37% from 2011 figures. Only four species saw their populations increase. The grass-feeding Meadow Brown was up 21% and the Scotch Argus, which thrives in damp conditions, rose by 55%.

Dr Tom Brereton, Head of Monitoring at Butterfly Conservation, said: "2012 was a catastrophic year for almost all of out butterflies, halting progress made through our conservation efforts in recent years. Butterflies have proved before that given favourable conditions and the availability of suitable habitat they can recover, but with numbers in almost three-quarters of UK species at a historically low ebb, any tangible recovery will be more difficult than ever.

Data was gathered by the UK Butterfly Monitoring Scheme (UKBMS) jointly led by Butterfly Conservation and the Centre for Ecology & Hydrology (CEH).

UKBMS has run since 1976 and involves thousands of volunteers collecting data every week throughout the summer from more than 1,000 sites across the UK. CEH butterfly ecologist Dr Marc Botham said: “Despite the horrific weather in 2012 over 1,500 dedicated volunteers still managed to collect data from over a thousand sites across the UK. Their amazing efforts enable us to assess the impacts of wet summers on butterfly diversity.”
The UKBMS is operated by the Centre for Ecology & Hydrology and Butterfly Conservation and funded by a multi-agency consortium including the Countryside Council for Wales, Defra, the Joint Nature Conservation Committee, Forestry Commission, Natural England, the Natural Environment Research Council and Scottish Natural Heritage. The UKBMS is indebted to all volunteers who contribute data to the scheme."

Dr Tom Brereton

Head of Monitoring at Butterfly Conservation


But it’s not too late if we act now …

In Sussex, last ‘summer’ checked the upward population trend for the rare Duke of Burgundy. Nevertheless, our conservation efforts over the previous years means that 2012 will have seen a decrease, not an extinction, of this rare and beautiful butterfly. This tells me that we must highly value and protect what we have. It tells me we must continue to research and keep learning - we may only have 59 native species of butterfly in the UK but there is still much we do not know. We must learn from our successes and we must learn from our mistakes. We must educate and we must conserve. We have no control over the weather but we do over our attitudes and actions – we have the ability to change things.

If you have the time and the ability to get involved with a local conservation project, run by your local branch of Butterfly Conservation, then please consider getting involved. You won’t regret it, and I can guarantee you will get far more out of it than you put in.

We have a responsibility …

Controversy ...

National disgrace ...

"Due to the care of past curators, we can (for example) still handle specimens actually from Linnaeus's personal cabinets, as well as others collected and prepared by later giants in the history of biology, Raffles, Darwin and Wallace among them. Ownership of these collections in trust carries an obligation to maintain them in good state and to make them accessible to enquirers and research workers at home and abroad".

Earl of Cranbrook, 1991. Standards in the Museum Care of Biological Collections, 2, 1992. Museums & Galleries Commission.



In early November 2012, The Museums Association (MA) held their annual Conference and Exhibition at the Edinburgh International Conference Centre (EICC). Reported to be the largest gathering of museums and heritage professionals in Europe, it showcases suppliers, hosts workshops and various meetings. Darren Mann of the Hope Entomological Collections (HEC) was there as a speaker to present a talk entitled ‘The Elephant in the Room’ which tackled some of the difficult questions that are currently being raised about the future of natural history collections in the UK.

What questions are those?
Well, here is the background in a nutshell:

"Natural history collections are under threat but are vital for taxonomic research, environmental monitoring and education. The number of specialist curators is declining, so should collections be redistributed to centres of excellence or are there other solutions for orphaned collections?"

The main question that is raised by this is - How do we prevent the loss of these collections? and it is one that is very much on the minds of all natural history curators at the moment as we hear of more collections being 'moth-balled' (put away into storage) and the loss of curators through redundancies or down-sizing, leaving many collections without people to care for them, interpret them or make them available for research. The biggest threat of course, comes to the collections themselves, which may become damaged or lost altogether through poor storage and lack of care. For example, any item with fur, feather or chitin (e.g. taxidermy mounts or insect specimens) are open to attack from a host of pests including the one most reviled by curators, Anthrenus, which, whilst being a rather pretty little beetle, views an insect collection as an assemblage of tasty snacks (see image below). In a round up of the problems associated with deciding the future of these collections, Darren Mann pointed out that despite their huge popularity with the general public there has been a movement in the museums sector away from natural history and towards the arts and social sciences. To put some perspective on this, the Ashmolean Museum recently spent £7.83 million on Edouard Manet’s Portrait of Mademoiselle Claus; a single painting! For the same amount of money the entire UK entomological collections held outside the Nationals and University Museums, of over 10 million specimens, could have been re-housed (including salary costs) and systematically arranged in modern pest proof storage.

One curator recently wrote "There are now more pandas living in Edinburgh than there are natural history curators employed in the whole of East Midlands, West Midlands and South Yorkshire put together".

This surely can't be right?



Images copyright OUMNH. Photographed by Katherine Child, Hope Department of Entomology.

Progress ...

Heyshott Escarpment, 24 October 2012

Today saw the fourth of our weekly conservation work parties at Heyshott Escarpment.

Fabulous results have already been achieved this season, as a large amount of scrub and secondary woodland has successfully been cleared. In addition, records were smashed today as, for the first time in memory, we cleared so much scrub that three substantial bonfires were required; the tiny holes that cover my clothing standing testament to the intensity of the heat of their aerial embers.

Much of the area we are currently working on is the site of an old rubbish tip linked to the former chalk quarry; as numerous old metal buckets, fragments of broken glass and barbed wire were found. Nearby lies the site of the old limekilns which once served the industrial process; we are currently working just to the northwest of this area. The image below, which I took on 12th March 2012, shows the eastern sector of the reserve looking south. The 'Camels Humps' are just visible to the left of the centre of the picture; just to the right of the chalk track. An area of cleared ground lies just to the right. The old limekilns are located just to the north of this area. As I left the reserve shortly after 1pm, a Small White and a Comma made the most of the sun, which was just starting to burn through the lifting cloud …

Roll on next week ...

Party season ...

Heyshott Escarpment, 3 October 2012

As September draws to a close it heralds the start of the annual conservation work party season.

Today, I joined Sussex BC and UKB member Colin Knight, and several representatives of the Murray Downland Trust, for the first of our weekly habitat management sessions at Heyshott Escarpment; these will run until the end of March next year. As this was the first get together this season, I was extremely pleased we started on the relatively flat and easy terrain of the lower reserve; as the upper slopes were very slippery due to the recent heavy rain.

One of the key aims of this ongoing programme is to create and maintain habitat corridors at this nationally important site for the rare Duke of Burgundy. This is an extremely exciting project and one where positive management and hard work continues to improve the chalk downland habitat. The extensive scrub clearance achieved during the previous season has now settled and, as it prepares to rest for the coming winter, looks highly promising for primula development in the forthcoming year. The gorgeous female below was photographed at Heyshott on 22nd May 2012; a beautifully warm and sunny day.

Do we need a better reason to turn up every Wednesday ...

I don't think so ...

100 miles and 2 hours later …

East Blean Woods, 20 June 2012

… I finally arrived at my destination, East Blean Woods in Kent, my target the beautiful Heath Fritillary (Melitaea athalia). I arrived at around 7.45am, much later than planned, though my final decision to visit wasn’t made until around 5.15am when I woke after an unsettled night. The temperature, a humid 16°C, had already raised a number of males into flight, the dappled light conditions proved challenging …

Managed by the Kent Wildlife Trust, East Blean Woods covers 122 hectares of ancient woodland and chestnut coppice situated on a patchwork of differing soils. It holds protected designation as a National Nature Reserve (NNR), a Site of Special Scientific Interest (SSSI) and Special Area of Conservation (SAC). The woods have historically been managed and after the coppice is cut, much of the ground is colonised by Common Cow-wheat (Melampyrum pretense), the primary larval food plant of M. athalia.

In 1934, the artist and lepidopterist F. W. Frowhawk wrote, “During the past half-century this butterfly has disappeared from many of its haunts where it was formerly abundant, and now occurs only in a few of the southern English counties. Its chief localities are in Kent, Devon and Cornwall; in Sussex it was formerly common, but now exists only in limited numbers.” He goes on to say “In Essex, where several females were liberated about ten years ago, it is now abundant.” He also claims “Its apparent extermination in certain localities was largely due to over-collecting, combined with extensive rearing of pheasants, as both the young and old of this bird, especially during the breeding season, destroy an enormous number of insects, especially ground-feeding larvae.” Fortunately the butterfly still occurs in Kent, Essex, Devon, Somerset and on the Devon-Cornwall border, albeit in much reduced numbers, though it has sadly long been lost from my home county of Sussex. The Exmoor and East Blean colonies are currently recognised as its principal strongholds. This is one of Britain’s rarest butterflies, which without carefully targeted conservation efforts, i.e. burning and bracken control on Exmoor and coppicing and ride widening in the Blean Woods complex in Kent, it is inevitable that a rapid decline of this delicate species would be seen. Long may its presence grace our countryside ...

A freshly emerged female below ...

Open day ...

Heyshott Escarpment, 19 May 2012

Males, females, courtship, mating, egg laying and territorial behaviour - today can only be described as an absolute success, as I was joined by a mixed group of around 58 people on the Duke of Burgundy open day at Heyshott Escarpment, organized jointly by the Murray Downland Trust and Sussex Butterfly Conservation.

Arriving early, to help set up the marquee before the crowds began to arrive for the 10.30 kick off and the first of our two guided tours of the reserve, I couldn’t help but think that today would be successful. The temperature was good and the weather conditions were perfect for a day of emergence and activity on this site that radiates calm and inspiration. We were not disappointed as a count of 31 Dukes was recorded, along with a small selection of other spring downland species. The Duke of Burgundy far outnumbered any other species. Of particular interest to me, was the sighting of a single female flying from the established Duke colony on the eastern slopes down into the lower slopes cleared this past winter.

Fingers crossed …

On the edge ...

Conserving the Duke of Burgundy, 28 April 2012

Yesterday I attended a Duke of Burgundy workshop organised by Butterfly Conservation and held at the Queen Elizabeth Country Park near Petersfield in Hampshire.

The event was billed as “An opportunity to share experience of the ecology and conservation of one of Britain’s most threatened butterflies, looking at examples from around the country. An indoor session of talks will be followed by a site visit to Butser Hill, one of the largest Duke colonies in the country, to look at suitable habitat, management techniques and (weather permitting!) see the butterfly”.

Dr Dan Hoare opened the proceedings giving a detailed and very interesting and informative outline of the Dukes on the Edge Project (conserving the Duke of Burgundy in southeast England). Dan was followed by Neil Hulme, who gave a comprehensive and experienced talk covering the efforts being undertaken to conserve the Duke in Sussex, with particular reference to Heysott Escarpment. The most important message that came across, was that of long-term conservation being about the successful maintenance of numerous metapopulations existing over networks of suitable habitat on a landscape rather than localized scale. Tim Bernhard followed and presented the findings from his research project “A comparative study of the Duke of Burgundy in woodland and downland in Hampshire”. Dr Sam Ellis (Butterfly Conservation's Senior Regional Officer) finished the highly thought provoking indoor proceedings explaining the conservation activities being undertaken in northern England at the Duke's most northerly range.

Following a brief interlude for lunch, those of us hard enough (or maybe that should be foolhardy) and with climbing gear at the ready, headed for the beautiful Butser Hill National Nature Reserve in what can only be described as “not the best weather conditions”. The advice of “bring appropriate clothing and footwear – the field visit involves significant steep slopes and uneven ground” was well placed as the ground was often slippery under foot and the slopes were extremely steep. Though sheltered in the valley floor, the cold driving wind, rain and low cloud really wasn’t welcomed, particularly as we headed back to the car park.

A beautiful site and one I will definitely revisit …

When the weather improves ...

Cricket season …

Lord's Piece, 15 April 2012

The Field Cricket (Gryllus campestris) is a large, glossy black cricket (in its adult form) with a distinctively large head, particularly in the male. The nymphs exhibit a beautiful golden pubescence. It is one of the rarest insects in the British Isles and is confined to a small area of the South Downs in West Sussex and Hampshire. Its habitat has been destroyed over much of its former range and it now exists in only one native site but has been introduced to a series of other suitable locations. It is now the subject of a Species Recovery Programme, having reached an estimated population low of just fifty pairs in 1991, all in one small area of West Sussex, the second known colony having gone extinct two years previously.

It can be difficult to see G. campestris without potentially damaging its habitat and this is not permitted because it is a protected species in the UK. Access to the release sites is very restricted because the populations are still extremely fragile and vulnerable to disturbance. However, their beautiful song can be heard from a distance of more than 100m on warm days during May and early June. If they are present, you will quickly know about them. A search of entomological literature suggests that G. campestris has long enjoyed a reputation far outweighing its proven presence in England. This is largely due to the writings of Gilbert White who described part of its life history, as well as that of the secret art of tickling them from their burrows (nymphs and adults will rapidly retreat down their burrows when disturbed but may be induced to come out again by the gentle insertion of a blade of grass).

Today, along with my son, I joined good friend and fellow entomologist Mike Edwards, who has been leading the Gryllus recovery programme for over 20 years. Our task, to find, photograph and capture final instar nymphs for relocation at a nearby partner site.

Please note: Our activities were being carried out in line with current best practice and legislation. It is illegal to disturb or interfere with Field Crickets in any way unless doing so under the conditions of a licence issued by English Nature.

I hope they enjoy their new home ...

I'll be back when the adults are singing ...

Dukes on the Edge …

Heyshott Escarpment, 12 March 2012

The Duke of Burgundy is one of the UK's fastest declining butterflies, having suffered a population drop of 35% from 1979 to 2008. It has disappeared from at least 153 of its former known sites. Butterfly Conservation’s ‘The Dukes on the Edge’ project (2011-2014) is targeting an area in the South East of England where the rapidly declining butterfly is clinging to survival.

Heyshott Escarpment, located within a small corner of the South Downs National Park, is one of the Duke’s few remaining strongholds. However, this is only being achieved by the continuing conservation efforts of a small group of dedicated individuals under the guidance and leadership of Neil Hulme (Sussex Butterfly Conservation) and ecologist Mike Edwards (The Murray Downland Trust). Work, undertaken by volunteers in both Kent and Sussex, has shown that populations can recover where appropriate habitat management is implemented and this is the trend currently being observed at Heyshott. The Duke of Burgundy is reliant on scrubby calcareous grassland and sunny woodland clearings where its eggs are deposited on cowslip, or primrose in more wooded environments. Changes in the nature of agricultural and forestry practices have led to required habitats becoming overgrown and consequently unsuitable. As the Duke has struggled to find the food plants it needs to breed and prosper, it has sadly become extinct across much of its former range in the UK. Butterfly Conservation is leading the fight to save this fascinating butterfly and through the Dukes on the Edge project aims:

To assess the status of the Duke of Burgundy and its habitat
To maintain and enhance existing habitat and create new Duke of Burgundy habitat (e.g. through coppicing, ride management, scrub management)
Undertake reintroductions on selected sites
Monitoring the impact of management on habitat condition and the butterfly's population.

Project activities:

Public events to raise awareness of the conservation importance of the South Downs for the Duke of Burgundy
The creation of a ‘Dukes on the Edge Action Group’.
Mapping of the locations of managed habitat, together with Duke of Burgundy records on GIS
Training events for volunteers to enable them to participate in conservation tasks, surveying and monitoring

Please support the Duke in your area ...