Nature’s Top 40: Britain’s Best Wildlife. Chris Packham

      Because the light organs are set on her underside, the female also has to twist her abdomen around to make sure that any males flying past will see her lights. This twisting is often accompanied by a swinging of her abdomen from side to side like a metronome, which, to complete the exhibition, gives the effect from a distance of the light brightening and dimming.

      The display usually lasts for a couple of hours, after which, if she hasn’t been successful in attracting a mate, she turns off the light and retreats back into the grassy tussocks to prepare for a repeat performance the following night. The females are remarkably sedentary and are often seen displaying from the exactly the same spot until they either snag a mate or die an exhausted spinster after around ten consecutive nights of lighting up the night.

      The numbers of glowing females can vary enormously from just a few females at small sites, to Brush Hill in Buckinghamshire, the location thought to contain the largest colony of glow-worms in Britain, with 320 females counted in one visit in 2007.

      The male glow-worm looks very different to the female, because he has to be mobile in order to track down the displaying females, and so has a fully functioning pair of wings tucked away under his wing cases. He normally takes flight shortly after the females have started glowing and flies a couple of metres above the ground until he spots a virgin female. He will then drop out of the sky with unerring accuracy next to the female and attempt to climb on her back. It is not uncommon to have a number of suitors chasing a single female, meaning a form of rugby scrum can sometimes ensue as they jostle for position.

      Like the adult female, the male cannot eat and so has a very limited adulthood. Once mating is over, the exhausted male dies, usually no longer than a week after emerging from his pupa for his date with destiny. His death is closely followed by the female’s after she has dutifully discharged her eggs to produce the next generation.

      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

       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