Predators of the Erinaceus europaeus include dogs, foxes, snakes, large owls, and badgers. To protect themselves, hedgehogs have the ability to curl into a defensive ball that exposes only erected spines. In order to form into a ball, they constriction the panniculus carnosus muscle. When this occurs, the muscles associated with each spine contract, leaving all of the hedgehog’s spines erect. Some predators, such as badgers and foxes, may be able to gain access to the hedgehog by wedging their noses into the crease where the top and bottom of the spiny coat meet. Predators have also been known to drop a balled hedgehog from a height so as to shock or injure the hedgehog long enough for them to take advantage of its exposed underbelly.
Known Predators:
The European hedgehog is a small, round animal with short legs that raise it about 1 inch above the ground. It is plantigrade and has 5 well developed pads and claws on each foot. The first and fifth toes are smaller and weaker than the second, third, and fourth toes. Its coat is white and brown and consists of 3/4 to 1 inch spines, arranged in a radiating pattern, that cover all but its cheeks, throat, stomach, and limbs. Areas not covered in spines are covered in a coarse hair that is yellow-brown in color, though white hedgehogs have been seen. It has an elongated, conical head and snout, a small braincase, a short neck and tail, and well developed eyes and ears. The length of its body ranges from 135 to 265 mm, and males are usually slightly larger than females. The tail is about 20 mm long.
The spines covering the European hedgehog's body have white tips and bases and are covered with alternating brown and black bands. They are hollow and have longitudinal grooves, which decrease their weight. Spines are made of keratin and are attached to the skin in a similar way to hair. Each spine grows from a follicle in the skin that is attached to a small muscle (arrector pili) that is used for piloerection. When a hedgehog rolls into a ball, all of the spines can be erected simultaneously, which is made possible by the panniculus carnosis, a sheet of muscle that covers its back. An adult hedgehog usually has around 5,000 spines covering its body.
Erinaceus europaeus has lacteal and permanent teeth. The permanent dentition features widely space upper incisors such that the lower incisors fit between them. The dental formula for E. europaeus is 3/2, 1/1, 2/3, 3/3.
Range mass: 800 to 1200 g.
Range length: 135 to 165 mm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger
Average basal metabolic rate: 2.434 W.
In the wild, European hedgehogs can live up to six years. In captivity, they can live as many as ten years.
Range lifespan
Status: wild: 8 (high) years.
Range lifespan
Status: captivity: 11.7 (high) years.
Typical lifespan
Status: wild: 6 (high) years.
Typical lifespan
Status: captivity: 10 (high) years.
The European hedgehog is found in temperate fields, especially field edges and hedgerows. They prefer drier areas that are not thickly wooded and are occasionally found in scrub and sand dunes. European hedgehogs are commensal and are often found in home gardens, cemeteries, parks, agroecosystems, and other areas that provide appropriate places for hibernation. It commonly occupies elevations from sea level to 2400 m throughout its geographic range.
Range elevation: 0 to 2400 m.
Habitat Regions: temperate ; terrestrial
Terrestrial Biomes: savanna or grassland ; forest ; scrub forest
Other Habitat Features: suburban ; agricultural ; riparian
Erinaceus europaeus (European hedgehog) is commonly found across Europe and into central Asia. Native to this region, it can be found from the Archipelago of the Azores and as far east as Khazakstan. It is commonly seen in northern Europe, as far as Scandinavia. While it is generally not found south of the Mediterranean Sea, it has been seen in Lebanon. Erinaceus europaeus is also found in New Zealand, where they were introduced in the late 1800s.
Biogeographic Regions: palearctic (Native ); australian (Introduced )
European hedgehogs are omnivorous, but predominantly feed on insects. They favor beetles, ants, bees, wasps, earwigs, butterflies and moths. Hedgehogs may also eat cockroaches, crickets, grasshoppers, snails, eggs, lizards, snakes, frogs, small rodents, and carrion.
Animal Foods: birds; mammals; amphibians; reptiles; eggs; carrion ; insects; terrestrial non-insect arthropods; terrestrial worms
Plant Foods: seeds, grains, and nuts; fruit
Primary Diet: omnivore
Hedgehogs are omnivorous, feeding on a wide variety of animal (especially insect) and plant material. They may help control insect pest populations in some areas. Hedgehogs are hosts to a variety of parasites including nematodes (Crenosoma striatum, Eucoleus aerophilus, Capillaria erinacei, Capillaria ovoreticulata and Capillaria spp.), trematodes (Brachylaemus erinacei), acanthocephalans (Oliganthorhynchus erinacei), ticks (Ixodes hexagonus), and fleas (Archeopsylla erinacei).
Commensal/Parasitic Species:
Hedgehogs are routinely kept as pets, but the European hedgehog is forbidden as a pet in Europe. Due to their broad diet, hedgehogs may help control insect pests. They have proven useful for the study of numerous diseases including foot and mouth disease, yellow fever, and influenza. Their hair and spines are useful in assessing for environmental pollutants including arsenic, silver, cadmium, lead, cobalt, and Persistant Organic Pollutants (POPs). Traditional remedies have incorporated the blood, entrails, or ashes of European hedgehogs, and some rituals involving hedgehogs have been used to cure baldness and predict the weather. Ancient Romans raised hedgehogs for their meat, and they used parts of the hedgehog, especially their spiny coat, for training work animals.
Positive Impacts: pet trade ; food ; body parts are source of valuable material; research and education; controls pest population
Hedgehogs are potential vectors for a number of parasites and pathogens including ticks, fleas, mites, ringworm, influenza, yellow fever, Salmonella enteritidis, leptospirosis, and foot and mouth disease.
Negative Impacts: injures humans (carries human disease); causes or carries domestic animal disease
Formerly a common sight in the UK, local populations of Erinaceus europaeus appear to be rapidly declining. Despite this, E. europaeus is listed as a species of least concern on the IUCN's Red List of Threatened Species. The reasons for its decline are unclear, however, E. europaeus has been included in the UK Biodiversity Action Plan.
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
European hedgehogs are not particularly noisy, and make mostly grunting, snorting, and hoarse squeaking sounds. Adults are vocal during mating, while feeding, and occasionally when captured. Young may squeak and whistle while in the nest. Due to its nocturnal behavior, European hedgehogs rely heavily on their senses of smell and hearing. In addition to having a well developed sense of smell, they, like many mammals, have a Jacobson's organ in their palate. The organ may have a role in social behavior as both male and female hedgehogs have a variety of scent glands. While the mechanisms of hearing in E. europaeus have not been well studied, research on a related species, the Long-eared hedgehog, has found it capable of processing high-frequency sounds up to 45kHz.
Communication Channels: tactile ; acoustic ; chemical
Other Communication Modes: pheromones ; scent marks
Perception Channels: visual ; tactile ; acoustic ; chemical
European hedgehogs are solitary and non-territorial. They begin the mating process when a male encounters a female, at which time the male encircles the female while she lowers her head and makes a variety snorts, grunts, and hisses. If the male is successful in courting the female, he attempts to mount her several times. After numerous copulations, the male leaves the female, and does not provide any parental care to his offspring. He continues to roam alone and attempts to mate with other females until he begins preparing for hibernation. Males and females have multiple mates each season.
Mating System: polygynandrous (promiscuous)
Erinaceus europaeus begins mating in late spring (April or May) when the the animal emerges from hibernation. Males, which emerge 3 to 4 weeks before females, expand their home range during mating season to increase chances of finding a mate. When a male finds a mate, he circles her while she lowers her nose and becomes audibly defensive. The male may circle for several hours, making several attempts to mount. If the female continually rejects the male, he eventually leaves to find a receptive female. If she accepts him, she flattens her spines and lowers herself to the ground, which gives the male better access. To copulate, a male climbs onto a female's back and uses his teeth to hold onto her shoulder. Gestation last for about 35 days. Females give birth to four to six offspring per litter, and often have two litters per year. The second litter, which is born later in the year, has a reduced chance of surviving winter. New borns are about 3 inches long and weigh 0.3 to 0.9 oz. At birth, E. europaeus does not appear to have spines, which are concealed beneath their fluid filled skin. 24 hours after birth, the fluid is absorbed and the spines are revealed, and, 2 to 3 days later, the young’s musculature is developed enough to allow it to hold the spines erect. These white adolescent spines are replaced by darker spines after about 1.5 days. Pigmented adult spines replace the first two coats after about 2 to 3 weeks, at which time young begin to open their eyes and learn how to roll into a ball. Young are weaned by 4 to 6 weeks old, after which they become independent of parental care, and are able to mate by about 1 year.
Breeding interval: Hedgehogs breed seasonally, and can have up to two litters per season
Breeding season: April to September
Range number of offspring: 1 to 9.
Range gestation period: 30 to 49 days.
Range weaning age: 4 to 6 weeks.
Range time to independence: 4 to 6 weeks.
Average age at sexual or reproductive maturity (female): 253 days.
Average age at sexual or reproductive maturity (male): 253 days.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Average birth mass: 14.7 g.
Average number of offspring: 1.5.
Average age at sexual or reproductive maturity (male)
Sex: male: 253 days.
Average age at sexual or reproductive maturity (female)
Sex: female: 253 days.
Weaning usually occurs 6 weeks after birth, at which time young European hedhogs begin venturing out of the nest with their mother. They begin to forage and create an overwintering nest on their own. Most individuals are sexually mature by the first spring after their born.
Parental Investment: precocial ; female parental care ; pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female)
What can species as different as a hedgehog, a swift, and a glow-worm possibly have in common? To find out, we journey to southwest England. We’ll join two naturalists on a walk through the heart of Exeter, a city known more for its football club and cathedral than for its wildlife. You may be surprised at what we find.
The European hedgehog (Erinaceus europaeus), also known as the West European hedgehog or common hedgehog, is a hedgehog species native to Europe from Iberia and Italy northwards into Scandinavia and westwards into the British Isles.[3] It is a generally common and widely distributed species that can survive across a wide range of habitat types. It is a well-known species, and a favourite in European gardens, both for its endearing appearance and its preference for eating a range of garden pests. While populations are currently stable across much of its range, it is declining severely in Great Britain[2] where it is now Red Listed,[4] meaning that it is considered to be at risk of local extinction. Outside its native range, the species was introduced to New Zealand during the late nineteenth and early twentieth centuries.
The European hedgehog has a generalised body structure with unspecialised limb girdles.[5] It appears brownish with most of its body covered by up to 6000 brown and white spines.[6] The length of head and body is ~160 mm (6 in) at weaning, increasing to 260 mm (10 in) or more in large adults. It has an extremely short tail as an almost vestigial feature, typically 20 to 30 mm (0.8 to 1.2 in).[7] Weight increases from around 120 g (4 oz) at weaning to> 1100 g (40 oz) in adulthood. The maximum recorded weight is 2000 g (70 oz), though few wild specimens exceed 1600 g (55 oz) even in autumn.[5] Adult summer weight is typically somewhat less than in autumn, with an average of around 800 g (28 oz) and adult weights commonly as low as 500 g (18 oz).[8] Males tend to be slightly larger than females, but sex differences in body weight are overshadowed by enormous seasonal variation.[7]
The European hedgehog is unlike any other creature across most of its range. Where it co-exists with the northern white-breasted hedgehog (Erinaceus roumanicus), the two species are difficult to distinguish in the field, the latter having a white spot on its chest.[2] It is probably the largest hedgehog species and is possibly the heaviest member of the order Erinaceomorpha.[9]
Leucistic or "blonde" hedgehogs occasionally occur. Such specimens are believed to have a pair of rare recessive genes, giving rise to their black eyes and creamy-coloured spines; however, they are not strictly speaking albino. They are extremely rare, except on North Ronaldsay and the Channel Island of Alderney where around 25% of the population is thought to be blonde.[10] True albino morphs of the hedgehog occur infrequently.[6]
The European hedgehog is largely nocturnal. It has a hesitant gait, frequently stopping to smell the air. Unlike the smaller, warmer-climate species, the European hedgehog may hibernate in the winter. However, most wake at least once to move their nests.[11]
The European hedgehog is an insectivore. Its diet consists largely of earthworms, as well as snails and slugs, beetles, ants, bees and wasps, earwigs, cockroaches, crickets and grasshoppers, butterflies and moths, and caterpillars and other insect larvae.[12] Eggs of ground-nesting birds are also taken, and carcasses may be foraged on. Hedgehogs may also eat lizards, snakes, frogs, and small rodents.[12] Plant matter appears to make up only a negligible part of the hedgehog's diet.[13][14][15]
The breeding season commences after hibernation. Pregnancies peak between May and July, though they have been recorded as late as September. Gestation is 31 to 35 days. The female alone raises the litter which typically numbers between four and six, though can range from two to ten. Studies have indicated that litter size may increase in more northern climes. The young are born blind with a covering of small spines. By the time they are 36 hours old, the second, outer coat of spines begins to sprout. By 11 days they can roll into a ball. Weaning occurs at around six weeks of age.[16]
European hedgehogs may live to ten years of age, although the average life expectancy is three years. Starvation is the most common cause of death, usually occurring during hibernation. If alarmed, the animal will roll into a ball to protect itself. Many potential predators are repelled by its spines, but predation does occur. Remains of hedgehogs have been found in the stomachs of red foxes (Vulpes vulpes), European badgers (Meles meles) and pine martens (Martes martes). A large portion of these may be from hedgehog carcasses, especially roadkill. However, hedgehogs tend to be absent from areas where badgers are numerous.
Eurasian eagle-owls (Bubo bubo) and golden eagles (Aquila chrysaetos) are the only regular avian predators of this species and may even prefer them as prey. The owl, after grabbing the hedgehog by its face, tends to skin the mammal's prickly back with its talons before consumption, resulting in several hedgehog backs being found around eagle-owl roosts and nests.[17] In Spain, reduction of European rabbit (Oryctolagus cuniculus) numbers due to rabbit haemorrhagic disease has made the European hedgehog one of the top preferred prey species for eagle-owls.[18] Elsewhere, eagle-owls often prefer these hedgehogs to any other prey species, as the hedgehog can comprise up to 23% by number and 30.7% by biomass of eagle-owl prey remains.[19][20][21] On the Swedish island of Gotland the golden eagle may take larger numbers of hedgehogs than any other prey due to an otherwise low diversity of native land mammals, although the introduction of European rabbits has shifted the eagle's prey preferences there.[22]
The European hedgehog is endemic to Europe (including European Russia), with a global distribution extending from the British Isles and the Iberian Peninsula eastwards through much of western to central Europe, and from southern Fennoscandia and the northern Baltic to north-west Russia. It is present also on Mediterranean islands (Corsica, Sardinia, Elba, Sicily), on most of the French Atlantic islands as well as on British Islands (autochthonous and introduced).[23] It is an invasive exotic species in New Zealand and has probably been introduced to Ireland and many of the smaller islands where it occurs.[24]
Colonists took hedgehogs from England and Scotland to New Zealand on sailing ships from the 1860s to the 1890s mainly as a biological control against agricultural pests or as a pet.[25] Few survived the ca 50–100 days voyage,[25] but those that did had lost all their fleas. Animals found their first homes in the South Island, where their spread was helped by guards dropping them off at country railway stations. Hedgehogs were introduced to the North Island in the 1890s, but some were also transported from South Island between 1906 and 1911[25] and, from then on, their numbers increased at an exponential rate. By the 1920s they had become so numerous that game-bird hunters blamed them for reduced bag-sizes. Hedgehogs were declared noxious animals and a bounty of one shilling a snout paid by regional authorities for several years. By the 1950s, hedgehogs could be found over the whole country with the exception of the coldest wettest corner of the South Island and alpine areas of permanent snow. Nevertheless, hedgehogs have been seen climbing New Zealand glaciers. Hedgehogs do not reach the same weight in New Zealand as in colder parts of Europe. With its milder winters, New Zealand hedgehogs hibernate for only three months of the year so do not need to put on so much weight in autumn as their ancestors. In northern New Zealand, many hedgehogs do not hibernate at all. One of New Zealand's pioneer hedgehogs probably had faulty teeth for this feature is found in about 50% of today's animals. Most New Zealanders welcome hedgehogs in their gardens as they relish slugs and snails. Conservationists are less happy as hedgehogs compete for invertebrate food with native bush birds and prey on some rare insects, lizards and ground-nesting birds. As a result, extensive hedgehog-control programs are under way in some parts of the country, killing thousands of them. To judge by roadkill counts, North Island hedgehogs were at their highest numbers in the 1950s. Since then, roadkill counts have fallen dramatically from about 50/100 km to less than 1/100 km.[26]
The European hedgehog is found across a wide range of habitat types, encompassing both semi-natural vegetation types and those areas that have been heavily modified by man. The range includes woodland, grasslands such as meadows and pasture, arable land, orchards and vineyards as well as within the matrix of habitat types found in human settlements. It prefers lowlands and hills up to 400–600m, but is also locally present on mountains, exceptionally up to an altitude of 1500–2000m (e.g. Alps and Pyrenees).[27] Outside cultivated land it prefers marginal zones of forests, particularly ecotonal grass and scrub vegetation.[27]
Hedgehogs are most abundant within the gardens, parks and amenity land close to or within human settlements.[28] They are generally scarce in areas of coniferous woodland, marshes and moorland, probably because of a lack of suitable sites and materials for the construction of winter nests (or hibernacula), which have specific requirements.[6]
Generally, the hedgehog is widely distributed and can be found in good numbers where people are tolerant of their residence in gardens. To date, the IUCN classifies the species as Least Concern and currently the population as Stable. In some areas, they are common victims of road kills and may be hunted by dogs, such as in Sardinia.[2] On 28 August 2007, the new Biodiversity Action Plan included the European hedgehog on the list of species and habitats in Britain that need conservation and greater protection.[29][30]
In Denmark and Poland, the European hedgehog is protected by law. It is illegal to capture or hurt them, but the housing of underweight hedgehogs found outside during winter is accepted.[31][32] It is protected in all European countries which have signed the Berne Convention on the Conservation of European Wildlife and Natural Habitats.
A low coverage assembly of the genome of Erinaceus europaeus was released by the Broad Institute in June 2006 as part of the Mammalian Genome Project.[33]
An estimate of 36.5 million by Burton[34] was based on extrapolating up from a density of 2.5 animals/ha (one per acre), but this was based on limited data and is probably an overestimate. A more recent estimate of 1,550,000 in Great Britain[35] (England 1,100,000, Scotland 310,000, Wales 140,000) is more reliable, but still has a high degree of uncertainty as it is based on very limited information about hedgehog density estimates for different habitat types.[3] Given this figure, and more firmly established rates of decline,[36] it is now thought likely that there are fewer than a million hedgehogs in Great Britain.[37] In the UK badgers are the main predator of hedgehogs,[38][39] and also compete for some of the same foods. Badger numbers have increased substantially in recent years due to increased legal protection, and increased predation by badgers may well be a major cause of declining hedgehog numbers in England.
In 2007 the hedgehog was classified a Biodiversity Action Plan "priority" species in Britain, largely in response to negative trends identified in national surveys such as Mammals on Roads survey,[40] run by People's Trust for Endangered Species (PTES), that found an annual decline in counts of road casualties of around 7% from 2001 to 2004.[41][42] Historic data from the National Gamebag Census suggest a steady decline between 1960 and 1980.[43] Evidence from a questionnaire in 2005 and 2006 also supported an ongoing decline, with almost half of ~20,000 participants in PTES' Hogwatch survey[44] reporting the impression that there were fewer hedgehogs than there were five years earlier.[45]
A review of the available survey data for the population trend of the hedgehog in Britain was undertaken by the British Trust for Ornithology (BTO) in a report commissioned by PTES and the British Hedgehog Preservation Society (BHPS).[36] This concluded that, at a conservative estimate, 25% of the British hedgehog population had been lost in a decade.[46] The report also highlighted the importance of long-term monitoring to provide datasets with sufficient power to allow the changes to the population to be identified. Currently, the most important monitoring programmes involved in collecting information about the status of the British hedgehog population are PTES’ Mammals on Roads and Living with Mammals surveys, and the BTO Breeding Bird Survey and Garden BirdWatch survey.[47] A recent review of these surveys now suggests that rural populations have declined by at least a half and urban populations by up to a third since 2000.[48]
This species has become a serious pest in areas where it has been introduced outside of its native range. One such location is the Western Isles of Scotland, where introduced hedgehogs eat the eggs of ground-nesting waders such as common snipe, dunlin, common redshank and northern lapwing. It is also considered a pest in New Zealand where it preys upon various native fauna,[49] including insects, snails, lizards and ground-nesting birds, particularly shore birds.[50] As with many introduced animals, it lacks natural predators.
Attempts to eliminate hedgehogs from bird colonies on the Scottish islands of North Uist and Benbecula in the Outer Hebrides were met with international outrage. Eradication began in 2003 with 690 hedgehogs being killed. Animal welfare groups attempted rescues to save the hedgehogs. By 2007, legal injunctions against the killing of hedgehogs were put in place. In 2008, the elimination process was changed from killing the hedgehogs to trapping them and releasing them on the mainland.[51]
The European hedgehog (Erinaceus europaeus), also known as the West European hedgehog or common hedgehog, is a hedgehog species native to Europe from Iberia and Italy northwards into Scandinavia and westwards into the British Isles. It is a generally common and widely distributed species that can survive across a wide range of habitat types. It is a well-known species, and a favourite in European gardens, both for its endearing appearance and its preference for eating a range of garden pests. While populations are currently stable across much of its range, it is declining severely in Great Britain where it is now Red Listed, meaning that it is considered to be at risk of local extinction. Outside its native range, the species was introduced to New Zealand during the late nineteenth and early twentieth centuries.
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