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 …

Research ...

Hope Department of Entomology, Oxford

Over the past couple of months, I have been fortunate to spend some considerable time in the good company of Pete Eeles at the Hope Department of Entomology at Oxford’s University Museum of Natural History (OUMNH). Pete, who runs the UK Butterflies website at www.ukbutterflies.co.uk, has added, and continues to add, considerable value to this excellent resource and it has been my pleasure to join him on what can only be described as a mutually rewarding adventure of discovery.

As an example of our earlier and continuing research the Large Blue (Phengaris (Maculinea) arion) has played a significant role. Our studies have involved tracking down specimens from lost colonies and reviewing historic literature relating to their final outposts e.g. from areas including North Cornwall, South Devon, Somerset, the Cotswolds and Barnwell Wold in Northamptonshire. The image capture process, expertly undertaken by Katherine Child (OUMNH), has provided an excellent means of better understanding the original descriptions and has provided an excellent graphical means of comparing regional colonies. Some of the specimens we have selected for inclusion are historic in their own right, in that they have been used in past reference works, not least, the Barnwell Wold specimens of P. arion from the important Dale collection, which feature on Plate 12, Figures 1 and 2, in Butterflies by E. B. Ford (pictured below).



Of the literature, which has been reviewed, the diaries and correspondences of the late James Charles Dale (1792-1872) have transported us to a period when Large Coppers, Mazarine Blues, Swallowtails, Bath Whites and other lepidopteran wonders graced our countryside. The middle image below, showing Dale's log from circa 1835, is of particular interest as it details the capture of Papilio arion, now Phengaris arion, from Mouse's Pasture, Bromham near Bedford. Examination of other diaries in Dale's archive also indicate reference to this location which is referred to in A History of British Butterflies by the Rev. F. O. Morris, 1853. Dale’s diaries and communications have sometimes been a challenge to read, but the effort has been worth it, as their contents continue to take flight into our imagination.

The search continues ...

Frogsporn ...

West Sussex, 8 March 2013

Overnight, and exactly a year to the day, my pond is once again awash with frogspawn.

I woke this morning to a mass of frantic sexual activity, with at least seven individuals taking part in this annual mating pilgrimage. Every year I keep watch for returning Common Frogs (Rana temporaria), their presence generally betrayed by their calling.

With heavy rain falling for most of today, I decided to keep my camera dry. The picture below was taken on 11 March 2012.


A positive sign of spring ...

Morphology ...

CONCENTRATING ON THE DETAIL

Most identification of Lepidoptera does not require the use of a dichotomous key (a means for the identification of organisms based on a series of choices between alternative characters), but relies on pattern recognition and learning the species verbatim from images in books and the internet, the ability growing with experience. However, in most other large orders (e.g. Diptera, Coleoptera and Hymenoptera) even the beginner must learn from keys, or diagnostic characters to be able to distinguish taxa even at the family level. Although there are exceptions, it is generally not until the lepidopterist begins to tackle the microlepidoptera that the use of morphological characters (e.g. genitalia, wing venation and body structure) becomes commonplace, and often a prerequisite, in aiding identification.

Most butterflies and moths have two pairs of overlapping scaled wings. These are comprised of an extremely thin double membrane with rigidity provided by a network of nervures (the hollow ‘veins’ which radiate from the base of and form the framework of the insect’s wing). The pattern of nervures is different for each genus of butterfly and, as such, this is one of the key criteria used by taxonomists when classifying butterflies.

To venture a little deeper, the fore and hindwings of most moths, though not all, are united during flight by a coupling apparatus, the frenulum (a bristly structure on the hindwings that holds the forewings and hindwings together). This particular mechanism is never found in butterflies, in which the wings are held together only because the front pair overlaps the hind to a considerable extent. The amount of this overlap is increased by the humeral lobe, a special projection found only in butterflies, and situated at the basal end of the costa on the hindwings. This type of arrangement is known as amplexiform (clasp-like) wing-coupling.

The image below, of a female Brown Hairstreak (Thecla betulae), shows the humeral area, close to the rear and either side of the thorax. In addition, key wing venation is visible, including the radial and medial veins on the hindwing, and the radial, cubital and anal veins located on the forewing. The discoidal cell of the forewing is also clearly discernable.

A  Humeral area

B  Radial nervure (vein)

C  One of the medial nervules

D  Radial nervure (vein)

E  One of the cubital nervules

F  Cubital nervure (vein)

G  One of the anal nervures (veins)

H  Discoidal cell

I appreciate that this level of detail, which by no means is digging very deep, is not to everyone’s interest. However, for those who have the time and the inclination to do so, I thoroughly recommend looking a little closer and you will soon discover a whole new world full of fabulous hidden wonders …

Try it sometime ...

First one to blink ...

Roe Deer

The roe deer, Capreolus capreolus, is primarily an animal of open mixed, coniferous or purely deciduous woodland but is also capable of adjusting to a wide range of other environments. It has also penetrated many towns, making use of gardens, parks and other open spaces where suitable food and cover exist. It may often be seen well out into open farmland, particularly when occurring at high densities.

Roe deer are indigenous to Britain, having been present since at least the Mesolithic period (6,000 to 10,000 bp). The clearance of forests and over-exploitation by hunting led to roe deer becoming extremely scarce in the medieval period. By 1700 it was considered extinct in southern and central England and all of Wales, surviving only in remnant woodlands in parts of the central and northwest Highlands of Scotland. A number of reintroductions during the Victorian era, and their subsequent natural spread aided by an increase in woodland and forest planting in the 20th century, has meant that roe deer have become widespread and abundant today.

A roe doe listens and watches ...

After dark ...

Bats in the attic?

Despite the loss of over 90% of our bats in the past 50 years or so, 18 species of these increasingly uncommon nocturnal creatures can sometimes still be found in southern Britain. Although legally protected, most species of these tiny intelligent mammals sadly continue to decline in numbers, mainly due to loss of habitat and changes in farming practice. All British bats eat only insects, populations of which have also reduced massively in the past fifty years or so. In Britain, a female bat has only a single baby (pup) each year, and often cannot give birth in poor summers; such as those we have experienced recently. Such slow reproduction makes it extremely difficult to reverse the decline of these beautiful and delicate mammals.

Most of our bats like to roost in trees, but a few species have adapted to take advantage of the opportunities offered by buildings at certain times of year. For example, a warmer environment can help a bat rear its pup during the summer. The pup is reared on its mother’s milk until it can fly, which may be as soon as three weeks after it is born. By autumn, the house dwelling maternity colony will typically be dispersing to mate and then to hibernate, perhaps in trees or underground sites.

Although they occasionally do, their presence needn’t worry householders – in fact most people remain quite unaware of their secretive little lodgers. Bats by their very nature are clean, gentle little animals, which spend much of their time grooming. They don’t build nests, so won’t bring any messy materials into the house and, perhaps most important of all, they don’t gnaw and chew at things, so won’t cause damage to electrical wiring and cables.

Bat droppings are sometimes found beneath roosts, but these are quite harmless and are not known to harbour disease. Droppings are sometimes seen on outside walls and windowsills near to roost entrances, but can also accumulate in lofts. If swept up after the bats have left, they make excellent fertiliser for houseplants. Bat and mouse droppings look very similar, but there is an easy way to tell them apart. Bat droppings consist only of the dried out fragments of insects and, if rolled between your finger and thumb, they will crumble away into dust; they also have a slight ‘sparkle’ about them. On the other hand, mouse droppings are solid, generally dull in appearance and remain in one piece.

Which bats live in houses?

The two very rare horseshoe bat species, the greater horseshoe (Rhinolophus ferrumequinum), and the lesser horseshoe (Rhinolophus hipposideros), like to roost in buildings, but are no longer regularly found in the south east of England. None have been recorded in Kent and Surrey for many years, and a mere handful remain in West Sussex. Usually found are our most common bats, the common pipistrelle (Pipistrellus pipistrellus) and the soprano pipistrelle (P. pygmaeus), which as crevice dwelling species, like to tuck themselves into gaps around the outside of properties rather than enter the loft space. They tend to do this mostly in the summer months when groups of females will cluster together in a warm spot to rear their young hidden beneath barge boards, hanging tiles and so on. In winter, odd individuals are sometimes found hibernating in similar gaps, but this time in the coldest rather than warmest places on the house. Perhaps surprisingly, pipistrelles seem very fond of modern houses, especially where small gaps and splits have opened for them into which they can squeeze. Though little more than an inch (2.5cms) in length, a pipistrelle can eat up to 3000 midges in a single night, and needs to do so to fuel its energetic lifestyle.

Another house specialist is the brown long-eared bat (Plecotus auritus), small groups of which will congregate in the lofts of (usually) older houses for a few months in the summer, again whilst the young are being reared. Larger than the tiny pipistrelle, it has huge ears, almost as long as its body, which it uses to listen by means of echolocation for its insect prey. The ears are tucked safely beneath the wings for protection whilst the animal is at rest. An individual bat will occasionally remain in a cold part of the loft to hibernate. A much rarer house dweller, and one of our largest bats, is the serotine (Eptesicus serotinus). Several times the size of a pipistrelle, it is still very small - a little over three inches (8cms) in length, although its wings may span over a foot (>30cms) in flight. These favour the lofts and attics of houses built at least 100 years ago where a few will occasionally roost during the maternity period. They have also been known to hibernate, usually singly, in roofs or cavity walls. Serotine bats are particularly fond of flying beetles such as cockchafers, which they catch on the wing. Other species of bat are much rarer in England and are very seldom found in houses.

Advice on your bats

If you have any concerns about bats in your property, do call the Bat Helpline on 0845 1300 228 – they can provide lots of advice and literature on bats, and even arrange free advice where building repairs, timber treatment and so on are necessary in or near a roost. Their web site www.bats.org.uk provides a wealth of information about bats, and many leaflets can be freely downloaded. They also run a rescue service – so if you find a grounded bat, give them a call and someone will be able to help.

Bats and rabies

The European strain of rabies found in bats is extremely rare in Britain. Only ten cases have been identified since 1986, all of them in a single species that does not roost in houses. There is no need to worry about rabies if you do not handle bats – the disease is only passed via a bite or scratch, or from an animal’s saliva coming into contact with eyes, mouth, nose or an open wound. As a precaution, bats should not be handled. If it is necessary to do so in the case of a grounded or injured bat, gloves should be worn - and don’t forget to call the Bat Helpline, as detailed above, for advice or support from a local bat worker.

My thanks to Martyn Phillis (Surrey Bat Group) for his assistance with this article. All images copyright Martyn Phillis.

Arvicola amphibius ...

European Water Vole

"Believe me, my young friend, there is nothing - absolutely nothing - half so much worth doing as simply messing about in boats”

Rat, Chapter 1 ...

Kenneth Grahame, The Wind in the Willows

The European water vole, Arvicola amphibius, Linnaeus (1758), formerly A. terrestris, is widespread across Europe where it lives in the well-vegetated banks of slow moving streams, rivers, dykes and other waterways. It is found throughout Britain where it is generally confined to low ground. It is absent from Ireland. The extensive waterside burrows of these strong swimmers have many levels that help to prevent flooding, as well as chambers for nesting and food storage. Burrow systems are typically located in the steepest parts of the bank and usually have underwater entrances to give the animals a secure escape route if danger threatens.

A. amphibius has a diet of grasses and waterside vegetation, though other broadleaved plants are also eaten. Where blades are bitten off the imprint of the two large incisors is both prominent and diagnostic. It is not uncommon to see "lawns" of closely manicured grass, occasionally with piles of chopped food, around burrow entrances. A. amphibius tend to be more active during the day than at night. The males range along about 130 metres of water bank, while females restrict their range to about 70 metres. Ranges of both sexes and all age classes are reduced during the winter period. They deposit their distinctive black, shiny faeces in latrines, which occur throughout and at the edges of their range and wherever they leave or enter the water. Three or four litters a year are typical. In mild springs the first of these can be born as early as March or April; though adverse conditions will delay breeding until May or even June. There are about five young in an average litter, which are born below ground in a nest lined with finely shredded grasses and reeds. Although blind and hairless at birth, the young develop quickly and are weaned at 14 days. On average, water voles only live about five months in the wild.

Their most important predators are mink and stoats; though other predators are known to take them. They have sadly experienced one of the most severe declines of any wild mammal in Britain during the 20th century. Changes in farming practices during the 1940s and 1950s caused the loss and degradation of suitable habitats but the most rapid period of decline was undoubtedly during the 1980s and 1990s when the American mink (Neovison vison) spread rapidly across the country having been released from fur farms. Between 1990 and 1998, the population dropped by a staggering 90%.

Arvicola amphibius is an excellent flagship species and one which we should endevour to protect. Their presence reflects a healthy aquatic environment and associated waterside communities.