Nature’s Top 40: Britain’s Best Wildlife

Although found all over Britain, glow-worm colonies are most abundant in southern England. They can be seen in grassland of every type, apart from sites that have been ‘improved’ with fertiliser or heavily sprayed with insecticides, and also occur in moorland, heathland and occasionally woodland. The spectacle is mostly a rural phenomenon, and country anecdotes abound of glow-worms being put in jam jars to read by at night!

The last 50 years are thought to have seen a steady fall in the number of colonies thanks to the usual lethal cocktail of habitat destruction, fragmentation and pollution. Artificial lights may well also present a problem as the males could be distracted by the lights and find it difficult to spot the females in the glare. Let’s hope, however, that these magnificent insects continue to bring light into our lives for many years to come.

37 Playing fox cubs (#ulink_30d8c32b-85ac-537a-bd59-88c7a0070d39)

You would think there could scarcely be enough room for a medium-sized native carnivore to live alongside us in Britain. Yet the cunning and resilient fox has led to it not just surviving, but actually thriving, anywhere from on rural farms to in the heart of Britain’s biggest cities. It’s a tough life, though, and particularly among the urban residents it’s a ‘live fast die young’ scenario, where cubs must learn the tricks of their trade quickly to give themselves a chance of breeding the following year.

Fox cubs

WHEN

Late April until the end of June

WHERE

Widespread and can be seen anywhere, although easiest seen in cities such as London and Bristol

A fox cub seemingly without a care in the world, but it can be a surprisingly short and brutal life.

Andy Rouse

The word ‘fox’ is considered a very old English word that came from the proto-Indo-European word ‘puk’, or Sanskrit ‘pucca’, which both mean tail. Our only native canid (member of the dog family) was widespread in Britain from the end of the Ice Age: evidence of fox remains reveals that the earliest human inhabitants hunted them for fur and meat. Despite a history of persecution through the Middle Ages, the number of foxes was scarcely reduced until the rise of pheasant shooting in the Victorian era, when an army of gamekeepers was employed to wipe out the ‘ vermin’. The liberal use of vastly improved guns, traps and poisons meant that, at the turn of the 20th century, foxes had been virtually exterminated from much of East Anglia and the large estates in eastern Scotland. But, as gamekeeping declined after the First World War, fox numbers recovered, and current estimates indicate the population has remained largely stable over the last 30 years at a pre-breeding population of 250,000 adult foxes.

Despite foxes being recorded from the length and breadth of mainland Britain, their distribution is far from even, with the highest densities occurring in southwest England, the Welsh Borders and up into southern Scotland. While foxes can be found anywhere from moors or woodlands to the centre of towns, they prefer fragmented habitats that are able to provide them with a wide range of cover and plenty of boundary edges along which they can hunt. Contrary to popular belief, despite the relatively recent colonisation of towns by foxes from the 1930s, 86 per cent of foxes are still thought to prefer living in the countryside, although a number may regularly move between the two.

The adult fox and its cubs are immediately identifiable but, on close inspection, many people are surprised by how small foxes actually are. A male dog fox weighs little more than 6.5 kilograms with an average body length of 67 centimetres plus a bushy tail adding a further 40 centimetres, while the female or vixen weighs even less, only marginally more than a domestic cat.

Their coat can vary in both colour and condition during the course of the year and they generally look at their scruffiest in the summer during their long protracted annual moult that begins in April. It is not until autumn that the old fur has fallen out and a new, shorter coat is revealed underneath. By the end of October or early November it is long, thick and ready for the winter.

In terms of sight, foxes do not enjoy the palette of colours available to the human eye and are often reliant upon movement for the object to register on their visual radar. However, their hearing at low frequencies is particularly acute, and is heavily used at dusk or night-time to track down the rustling of small mammals in the leaf litter. Once the sound is pinpointed, the fox will pounce on an unsuspecting mouse, vole or rat from as far as two or three metres away. A fox’s world is also dominated by smells, which are used to track down the next meal. Areas around the fox’s territory sprayed with urine are also capable of conveying a range of information about the owner, such as their identity or reproductive state.

While many sightings in both rural and urban areas are of solitary animals, most foxes are part of a group. Most consist of a clear hierarchy with a dominant dog fox and vixen, which will usually be the only pair to breed, a number of mostly subordinate females (female cubs from previous years that have not left the territory) and unrelated males. The number of subordinate foxes within the group will depend both on whether food is plentiful and on the local level of persecution, with favourable conditions leading to groups with as many as ten adults in addition to the alpha pair’s cubs.

The groups’ territories can vary enormously in size, with rural foxes generally making use of at least 1.5 square miles per group, as opposed to urban foxes where food is more easily acquired, which may have five territories crammed into each half square mile. In upland areas, where fox densities are lower and food is more difficult to locate, the territory may be as large as 12 square miles. The dog foxes will constantly man the borders of their territories after the cubs have dispersed in the autumn and in winter when the females are approaching oestrus. Upon confrontation with the neighbours, who are not deterred by a snarling match, the resident fox will frequently resort to fighting by rearing up on its hind legs and engaging in pushing and biting matches to try to drive the intruder away.

Foxes are able to mate only ten months after birth, with the mating peak occurring early in the New Year when the females come briefly into oestrus. A copulating pair can sometimes become locked together for up to an hour, a feature unique to the dog family; it is a time when both foxes can be left very vulnerable. This mating period is also the time when the bloodcurdling screams of the vixen and the triple bark of the male shatter the silence of the night as they stay in contact and assess the locations both of members of their group and any neighbouring animals.

Pregnancy lasts 53 days, during which time the vixen will select and clean a number of den sites or ‘ earths’ in which to raise her cubs. The chosen fox earth may be either self-excavated or an enlarged and disused rabbit warren or badger sett in the countryside, with favoured locations in the suburbs commonly being under garden sheds. Four to five cubs are usually born blind and deaf in mid- to late March. For the first two weeks, they will be constantly supplied with milk and attended to by the vixen; she, in turn, will be kept fed by regular provisions brought to the earth by the dog fox. When the cubs’ eyes and ears finally open they begin to stray much more until, after four weeks, they will eventually emerge blinking into the daylight as dark-chocolate-brown coloured fur balls.

Fox cubs playing. This is integral to honing their hunting techniques and sorting out a pecking order.

Manfred Danegger

Undoubtedly the best time to see the foxes’ social and playful side is the period between their emergence and the time when the cubs have to stand on their own four feet in the autumn. Initially they will then remain close to their earth, playing and engaging in mock fights. While they look like they don’t have a care in the world, these tussles are used to develop a social hierarchy and hone their hunting techniques, skills that could make the difference between life and death. As the cubs mature, they begin to spend their entire time above ground; they moult into their orangey-red fur, and their ears and snout elongate to produce the characteristic foxy appearance. The cubs are fed by their parents or other group adults at rendezvous points close to the den sites right up to July, by which time they will have started to hunt themselves.

The adults give the cubs very little training, so, initially, they are dependent mostly on easily caught food such as earthworms, beetles and small fledgling birds; if July is wet, more cubs will survive through to autumn as the worms will be easily accessible. As cubs begin to forage further away from the earth, their inexperience makes them vulnerable to predators such as other foxes, badgers, dogs and, of course, cars, so, where possible, they will try and use the centre of their parents’ territory where they feel most secure.

During each breeding season around 425,000 cubs are born, and, as the fox population remains fairly constant, this means that as few as four in ten cubs make it through to the following breeding season to replace the older animals. This could mean the average life expectancy of a British fox may be no more than a paltry 18 months. After being maligned in the countryside, where it does not get credit for keeping rabbit numbers in check, and undeservedly blamed for taking pets in the towns, is it now time to cut the fox some slack? Its resilience, adaptability and endurance in the face of an ever-changing Britain shows that, as a species, it has more in common with us humans than we dare to think.

36 Trapping moths (#ulink_08d998df-e001-5cdf-b339-1c2c28116e7a)

While butterflies are popular, iconic and colourful daytime insects familiar to everyone, moths have something of a PR problem. There seems a widespread misconception that moths are dull, boring and brown, and put on this planet to do little else than to chew our clothes and carpets. While a tiny minority do unfortunately have this tendency, and many can be brown, they are certainly not dull and boring as any moth trap will illustrate.

Moths

WHEN

Between May and July for most resident species of hawkmoth

WHERE

The moth trap can be placed anywhere from the garden to a local nature reserve

The angle shades looking less like a pair of sunglasses and more like a crumpled leaf.

Robert Thompson

The differences between moths and butterflies are numerous, complex, indistinct, and include frequent exceptions. The most obvious difference is that butterflies fly during the day, while the vast majority of moths are either crepuscular – flying at twilight – or nocturnal by nature. A close look at the antennae of the two groups will also reveal that most butterflies have slender antennae with a club on the end; moths either have feathery antennae or a pair of simple filamentous strands without clubs. In resting state, all of the butterflies, with the exception of the skippers, close their wings over their backs; moths, with the exception of the thorns, lay their wings alongside their bodies. Most moths also possess a frenulum, which is a small hook on their hindwings that attaches to barbs on the forewing, whereas the four wings of butterflies all operate independently. Finally, most moths tend to have hairy or furry-looking bodies, with larger scales on the wings to enable them to conserve heat at night, while the sun-loving butterflies do not need this extra insulation so have more slender thoraxes and abdomens.

Moths are also sub-divided into two groups called ‘macro-’ and ‘micro-’ moths based on their anatomical structure, but, as a few micro-moths are larger than macro-moths, this division can be complicated to the untrained eye. Virtually all macro-moths can be distinguished by the patterning on, and the shape of, the wing, which makes identification easier; the micros, on the other hand, invariably and unfortunately need their pressed genitalia to be examined down a microscope. Macro-moths are also much more numerous than our 59 resident butterflies, with over 800 species recorded in Britain. During a good night’s ‘moth-ing’ in the summer, the ‘moth-er’ can be rewarded with at least 100 species and possibly as many as 1,000 individuals from a specially designed moth trap.

That moths are attracted to artificial lights has been known ever since man made fire, hence the phrase ‘like a moth to the flame’, but the reasons why this happens are complex and still not fully understood. When watching how moths become attracted to a light or moth trap, it is very noticeable that many of the individuals appear to fly around the light in ever-decreasing circles, and the most common theory to explain this behaviour is that moths use a technique of celestial navigation called ‘transverse orientation’. By maintaining a constant angular trajectory to a bright celestial light such as the moon, the moths can fly in a straight line. As the moon is so far away the change in angle between the moth and the moon’s rays will be negligible, the moon will always be in the upper part of their visual field and no lower than the horizon.

‘Have the lambs stopped screaming, Clarice?’ The infamous death’s-head hawkmoth.

Stephen Dalton

Evolutionarily speaking, human light sources have been around for such a short space of time that the moths have not yet evolved the ability to ignore the light pollution we create. As a moth-trap light may be so much stronger than that of the moon when the insects are close by, they become confused and instead use the artificial light for navigation. But, as this light is below the horizon and the angle of the moth to the light changes markedly after only a short distance, the moths will instinctively attempt to correct this by constantly turning towards the light, causing them to spiral down to the light until they either hit it or drop into the moth trap.

A quick glance at any guide to British moths will soon make the reader aware of the infinitely varied colours of moths, with a number of species being easily as coloured and possibly even more intricately patterned than the butterflies. Many moths have been given wonderful common names as well, such as mother shipton, peach blossom or brindled beauty, which certainly adds to the fun of moth identification. Of all the wonderfully different 17 families of macros in Britain, though, without question the most spectacular group regularly encountered in moth traps are the hawkmoths.

The hawkmoths comprise about 850 known species worldwide and are most heavily represented in the tropics. The family includes such well-known species as: the infamous death’s-head hawkmoth that was immortalised in the film Silence of the Lambs; the day-flying hummingbird hawkmoth; as well as the long-tongued Darwin’s hawkmoth, which was predicted to exist by the great man after Darwin found an orchid that could only be pollinated by a proboscis of over 20 centimetres in length! The hawkmoths are moderate to large in size, with a wingspan of between 30 and 125 millimetres, and are characterised by their rapid flight, long, narrow hawklike wings and a streamlined abdomen, all clearly adaptations for quick and sustained flying. In addition to some species being able to hover, the hawkmoths are thought to be some of the world’s fastest flying insects, capable of travelling at 30 mph.

The larvae of hawkmoths are also larger than the vast majority of the other moth larvae, and can reach 80 to 120 millimetres long, with a surprisingly thick body and a horn clearly present on the eleventh segment, close to their rear end. The family’s Latin name, Sphingidae, comes from the posture adopted by the caterpillars: when they are resting on a twig, they cling to the plant with their pro-legs and hind claspers, while the front halves of their body rear up with the head curved back towards the twig, resulting in the caterpillars’ profile resembling that of an Egyptian sphinx.

The caterpillars have an incredible appetite and their weight before pupation may be ten thousand times that of when they initially hatched from their eggs; this means that, during their six-week larval stage, these ‘eating machines’ will have to moult at least three or four times. Although some hawkmoths are considerable pests to crops, such as the tobacco hornworm (hawkmoth) in the tobacco-growing areas of the USA, all of the British species confine their voracious appetites to a mostly abundant range of native plants.

The elephant hawkmoth derives its name from the grey, trunklike caterpillar, not from the startling pink and olive livery of the adult moth.

Laurie Campbell

If disturbed, the eyed hawkmoth will flash ‘the eyes’ on its hind-wings to give the impression that it is much bigger and scarier than it really is!

Robert Thompson

Some of the caterpillars, such as the poplar and eyed hawkmoths, are well camouflaged against their respective food-plants, with disruptive patterns making them difficult to pick out. However, a number of other species that feed on low-growing plants, like the immigrant spurge and bedstraw hawkmoths, often have conspicuous colours, presumably to act as a warning to birds of their distasteful nature, while elephant hawkmoth larvae have eyespots to startle would-be predators. Those caterpillars that avoid being predated will then bury themselves underground to pupate in the soil over winter.

In Britain there are nine breeding species, with a further eight that have migrated from continental Europe occasionally recorded at moth traps. The elephant hawkmoth is certainly one of those species that puts paid to the theory that all moths are brown, with its brazen pink and olive colouration. This small species is one of the most common hawkmoths in Britain and is widespread in England, Wales and southern Scotland. It is particularly common in urban areas, as its main food-plant is rosebay willowherb – that colourful coloniser of car parks, railway sidings and roadsides. The caterpillar is green or brown, speckled with grey, and has a pair of colourful eyespots on the fourth and fifth segments either side of the body, which become dilated when it is disturbed. The caterpillar’s body immediately behind the head is long and extendable and, when the caterpillar waves its head around while looking for the next meal, it has more than a passing resemblance to an elephant’s trunk, hence the name!