Living Organisms / Animalia / Craniata / Mammalia / Insectivora / Erinaceidae / Erinaceus / Species Erinaceus europaeus - West European hedgehog (Click photographs/illustrations: full picture & further details) |
INDEX - INFORMATION AVAILABLE |
|
|
|
|
|
|
||
Alternative Names (Synonyms) |
|||||||
Synonyms for 'hedgehog'; species not specified:
|
|||||||
Names for new-borns / juveniles |
Hoglets | ||||||
| Names for males | Boar | ||||||
| Names for females | Sow | ||||||
| Adult: Adult hedgehogs
have a short, rotund body with distinctive spines, small eyes and ears. Newborn: Neonates are about 6-10 cm long, pink, hairless, with closed eyes and ears. The spines appear through the skin soon after birth. |
|
Similar Species |
Unmistakable in the UK - no other similar
species (B142).
|
| Sexual Dimorphism |
|
Measurement & Weight |
|
| EDITORIAL SUMMARY | The following editorial comment
summarises detailed information given within the LITERATURE REPORTS. Links to the
LITERATURE REPORTS are provided at the bottom of this box. LENGTH HEIGHT WEIGHT GROWTH RATE (References are available in detailed literature reports below) |
| CLICK THE LINKS FOR Literature Reports | Literature Reports: West European hedgehog Erinaceus europaeus - Appearance-Morphology- Measurement and Weight |
Head and Neck |
|
| EDITORIAL SUMMARY | The following editorial comment
summarises detailed information given within the LITERATURE REPORTS. Links to the
LITERATURE REPORTS are provided at the bottom of this box. GENERAL HEAD
STRUCTURE: DENTITION: EYES: (References are available in detailed literature reports below) |
| CLICK THE LINKS FOR Literature Reports | Literature Reports: West European hedgehog Erinaceus europaeus - Appearance-Morphology- Head and Neck |
Legs, Spine and Tracks |
|
| EDITORIAL SUMMARY | The following editorial comment
summarises detailed information given within the LITERATURE REPORTS. Links to the
LITERATURE REPORTS are provided at the bottom of this box. The legs of hedgehogs are quite long but most of their length is not usually easily visible, being hidden in the skirt of hair along the flanks. The stance is plantigrade (they walk fully on the soles of the feet). The feet, each with five toes, bear long strong claws with a flattened profile. There is a marked difference in shape between the front and hind feet so that their respective tracks are easily distinguished. The forefoot tracks (excluding claws) are about 25 mm long by 25-30 mm wide and point inwards while the hind feet tracks are about 30 mm long and 20 mm wide, pointing outwards. The stride is about 10-15 cm long, the width between tracks about 3-6 cm. (References are available in detailed literature reports below) |
| CLICK THE LINKS FOR Literature Reports | Literature Reports: West European hedgehog Erinaceus europaeus - Appearance-Morphology- Legs, Spine and Tracks (Literature Reports) |
| EDITORIAL SUMMARY | The following editorial comment
summarises detailed information given within the LITERATURE REPORTS. Links to the
LITERATURE REPORTS are provided at the bottom of this box. The adult tail is about 2-2.5 cm long. (References are available in detailed literature reports below) |
| CLICK THE LINKS FOR Literature Reports | Literature Reports: West European hedgehog Erinaceus europaeus - Appearance-Morphology-Tail |
Skin / Coat / Pelage |
|
| EDITORIAL SUMMARY | The following editorial comment
summarises detailed information given within the LITERATURE REPORTS. Links to the
LITERATURE REPORTS are provided at the bottom of this box. Adult: Hedgehogs are basically brown in colour with spines over the dorsal surface and hair on the face, legs and underside. The hair coat on the face and underside is uniform in colour in Erinaceus europaeus, which is one of the features distinguishing this species from the closely related Erinaceus concolor. The spines, modified hairs about 20 mm long and 2mm thick, are not uniform in colour but banded brown and white; there may be a total of about 7,000 spines per hedgehog. The spines have a complex internal structure which allows them to act as an efficient shock-absorber, as well as being effective as a deterrent against many predators. Except for the juvenile moults spines are usually lost and replaced individually. The hedgehog has specialised cutaneous muscles which allow it to roll into a tight defensive ball. Adult Colour variations: include individuals with occasional white spines, "blond" hedgehogs with paler than normal colouration, true albinos with pink eyes and nose and white individuals with black eyes and nose. Melanistic (black/dark brown) individuals have not been recorded. Newborn/Juvenile: Newborn hoglets are pink and naked with a taut, bloated skin. The first white spines protrude through the skin soon after birth. The second, pigmented, set of spines starts to emerge after just a couple of days and by 2-3 weeks they obscure the first set. The third set of spines (adult) begin to emerge at about six weeks old. (References are available in detailed literature reports below) |
| CLICK THE LINKS FOR Literature Reports | Literature Reports: West European hedgehog Erinaceus europaeus - Appearance- Morphology- Skin-Coat-Pelage (Literature Reports) |
Detailed Anatomy Notes |
|
| EDITORIAL SUMMARY | The following editorial
comment summarises detailed information given within the LITERATURE REPORTS. Links to the
LITERATURE REPORTS are provided at the bottom of this box.
Further information is available within this section on the structure of the brain, male and female reproductive organs, gastrointestinal organs and adrenals. (References are available in detailed literature reports below) |
| CLICK THE LINKS FOR Literature Reports | Literature Reports: West European hedgehog Erinaceus europaeus - Detailed Anatomy Notes (Literature Reports) |
Life Stages / Natural Diet / Physiology
Life Stages |
|
| EDITORIAL SUMMARY | The following editorial
comment summarises detailed information given within the LITERATURE REPORTS. Links to the
LITERATURE REPORTS are provided at the bottom of this box. BREEDING SEASON: Hedgehogs are seasonal breeders with male sexual behaviour from March or April until August or September. In the UK nestlings may be found as early as April and as late as October. At higher latitudes the breeding season starts later and ends earlier while in New Zealand the main breeding season is November to March: a reverse of the northern hemisphere season. OESTRUS/OVULATION: Hedgehogs are seasonally polyoestrous. Data from one study indicate that many matings do not result in conception but a period of pseudopregnancy prior to the next oestrus; several cycles of oestrus and pseudopregnancy may occur before conception. Following gestation and birth there may be a period of lactational anoestrus although a post-partum oestrus has sometimes been described. Early loss of a litter is likely to result in rapid return to oestrus and fertile mating. In autumn females enter a period of seasonal anoestrus. GESTATION/PREGNANCY: Gestation has been calculated to last about 35 +/- 4 days; occasional records indicate the possibility of pregnancies lasting more than 40 days; this may be related to adverse environmental conditions triggering a period of torpor during (early) pregnancy. Hedgehog embryos are evenly distributed between the two horns of the uterus and post-implantation losses appear to be low. PARTURITION/BIRTH: Births may occur in Britain from May (rarely April) to September or even October. Sows construct a breeding nest or burrow within which they give birth. There have been few observations of parturition; disturbance around the time of birth carries a high risk of maternal cannibalism. Hoglets may be born in anterior (head first) or posterior (tail first) presentation. The fetal membranes and placenta from each neonate are eaten by the mother who moves her offspring carefully with her mouth and positions them by or under her belly. NEONATAL/DEVELOPMENT:
LITTER SIZE: Litter size in Britain averages four to five at birth. The range of litter size recorded is two to 10. About 20% of hoglets may die prior to leaving the nest. TIME BETWEEN LITTERS / LITTERS PER YEAR: In central and southern Europe, where the breeding season is longer, and in New Zealand, females may raise two litters in a single breeding season. In Britain it is probably rare that a female conceives, lactates and weans one litter then successfully repeats the process; one such instance has been recorded in captive hedgehogs (litters born May and August and weaned at 43-45 and 42 days respectively). Late litters in females showing evidence of prior lactation in the same season are probably more commonly due to early loss of the first litter. In geographical areas with a shorter breeding season, such as Sweden, only one litter is possible per year. LACTATION / MILK PRODUCTION: Lactation lasts about four to six weeks. Immunoglobulin absorption in the gut of the hoglets continues for at least 20 days and possibly 30 days or longer. Hedgehog milk is highly concentrated, rich in protein and fat and low in lactose. SEXUAL MATURITY: Sexual maturity may occur at about nine to 12 months old in the wild, i.e. in the year following birth, and possibly as young as six months in captivity. Pregnancy has been recorded rarely in females weighing as little as 400 g but more usually 550-600 g or higher. MALE SEASONAL VARIATION: The reproductive tracts of male hedgehogs show considerable seasonal changes. LONGEVITY / MORTALITY: In the wild, hedgehogs which reach five years old are considered to be "old" and maximum lifespan is probably six to eight years. In captivity 10 years may be reached and as high as 14 years has been reported. Average life expectancy in individuals which survive to weaning is probably two years. (Details of Age Estimation Techniques are available in the Detailed Literature Reports.) (References are available in detailed literature reports below) |
| CLICK THE LINKS FOR Literature Reports | Literature Reports: West European hedgehog Erinaceus europaeus - Life Stages |
| EDITORIAL SUMMARY | The following editorial
comment summarises detailed information given within the LITERATURE REPORTS. Links to the
LITERATURE REPORTS are provided at the bottom of this box. NATURAL DIET:
QUANTITY EATEN: STUDY METHODS: (References are available in detailed literature reports below) |
| CLICK THE LINKS FOR Literature Reports | Literature Reports: West European hedgehog Erinaceus europaeus - Natural Diet |
Hibernation / Aestivation |
|
| EDITORIAL SUMMARY | The following editorial
comment summarises detailed information given within the LITERATURE REPORTS. Links to the
LITERATURE REPORTS are provided at the bottom of this box. Hedgehogs hibernate as an energy-saving strategy and pass much of the winter in a state of hibernation, in which the body temperature falls, metabolism (including heart rate and respiratory rate) is greatly reduced and energy consumption is minimised. Normal hibernation is affected by various environmental and hormonal cues, with cold and lack of food shown to be important triggers. Hibernation is not essential and hedgehogs kept in warm conditions with food available will not hibernate; in nature hedgehogs in severe climates hibernate for long periods while those in mild climates (e.g. parts of New Zealand) may not hibernate at all. Hedgehogs periodically arouse from hibernation and it appears that most of the energy used over the winter is consumed during these short periods. In general males start hibernating earlier in the autumn than do females and become permanently active again earlier in the spring. Hibernation takes place in specially constructed winter nests or hibernacula. For details of physiological changes associated with hibernation see the relevant sections of the page: Literature Reports: West European hedgehog - Detailed Physiology Notes (Literature Reports) (References are available in detailed literature reports below) |
| CLICK THE LINKS FOR Literature Reports | Literature Reports: West European hedgehog Erinaceus europaeus - Hibernation - Aestivation |
| EDITORIAL SUMMARY | The following editorial comment
summarises detailed information given within the LITERATURE REPORTS. Links to the
LITERATURE REPORTS are provided at the bottom of this box.
Recorded blood values vary with age, sex, stage of hibernation and anaesthetic drugs used. HAEMATOLOGY:
BIOCHEMISTRY:
(References are available in detailed literature reports below) |
| CLICK THE LINKS FOR Literature Reports | Literature Reports: West European hedgehog Erinaceus europaeus - Haematology / Biochemistry |
Detailed
Physiology Notes |
|
| EDITORIAL SUMMARY | The following editorial comment
summarises detailed information given within the LITERATURE REPORTS. Links to the
LITERATURE REPORTS are provided at the bottom of this box. METABOLISM (TEMPERATURE):
RESPIRATORY SYSTEM (RESPIRATION):
CIRCULATORY SYSTEM (PULSE/HEART RATE):
GASTROINTESTINAL SYSTEM (FAECES AND GUT MOTILITY):
URINARY SYSTEM (URINE):
CHROMOSOMES:
MUSCULO-SKELETAL SYSTEM: Hedgehogs can roll into a tight ball with spines bristling in all directions as part of their defensive behaviours (Further information is provided in West European hedgehog Erinaceus europaeus - Social Behaviour / Territoriality (Literature Reports)). SPECIAL SENSES AND VOCALISATIONS:
(References are available in detailed literature reports below) |
| CLICK THE LINKS FOR Literature Reports | Literature Reports: West European hedgehog Erinaceus europaeus - Detailed Physiology Notes |
Feeding Behaviour |
|
| EDITORIAL SUMMARY | The following editorial comment
summarises detailed information given within the LITERATURE REPORTS. Links to the
LITERATURE REPORTS are provided at the bottom of this box. Hedgehogs forage in a variety of natural and man-made habitats. They may forage preferentially in areas likely to have high prey availability. They may show a bimodal feeding pattern, with one peak of activity and feeding early during the night and a second peak in the middle of the night or towards dawn. About 50% or so of the total active time is spent foraging. Hedgehogs locate their prey mainly using scent but also using sound. Hedgehogs show discrimination in prey choice and older hedgehogs may forage more efficiently than juveniles. Observation has shown specific behaviours such as wiping excess slime from large slugs using the forepaws, eating large earthworms from the hind end toward the head and biting a hole in eggs before extracting the contents by licking. They do not store or cache food for winter. Further information on diet is provided in West European hedgehog Erinaceus europaeus - Natural Diet (Literature Reports)) (References are available in detailed literature reports below) |
| CLICK THE LINKS FOR Literature Reports | Literature Reports: West European hedgehog Erinaceus europaeus - Feeding Behaviour |
Parental Behaviour |
|
| EDITORIAL SUMMARY | The following editorial comment
summarises detailed information given within the LITERATURE REPORTS. Links to the
LITERATURE REPORTS are provided at the bottom of this box. Only the mother is involved in rearing the offspring. Cannibalisation may occur if the boar is left with the sow in captivity. The sow may eat her offspring if disturbed soon after birth (the first few days); after this time disturbance is more likely to result in the sow moving the hoglets to a new nest site. Sows will retrieve youngsters in response to their shrill piping to about four weeks old, and will actively defend her litter if threatened. The sow and her offspring remain together until the hoglets are about five or six weeks old. Further information on reproduction is provided in West European hedgehog Erinaceus europaeus - Life Stages (Literature Reports) (References are available in detailed literature reports below) |
| CLICK THE LINKS FOR Literature Reports | Literature Reports: West European hedgehog Erinaceus europaeus - Parental Behaviour |
Social Behaviour / Territoriality / Predation / Learning |
|
| EDITORIAL SUMMARY | The following editorial comment
summarises detailed information given within the LITERATURE REPORTS. Links to the
LITERATURE REPORTS are provided at the bottom of this box. Hedgehogs have home ranges which remain relatively constant between years. The size of the home range may vary considerably between habitat types but adult males consistently have a home range larger than that of females or sub-adults in the same habitat type. The distance travelled per night is also longer for adult males than for females or sub-adults (averages of about 900 m for males, 600 m for females in a forest edge habitat and about 1.5 km for males, 1.0 km for females on a suburban golf course). This may be related to mating behaviour. Individuals may sometimes travel as far as 3-4 km in one night. Speeds of as high as 60m/min and 120m/min have been recorded but slower progress (about 2-4 m/min) is more usual. Home ranges of both females and males may overlap considerably with those of several other individuals. Aggressive interactions between hedgehogs are rare; mutual avoidance appears to be normal. Juveniles disperse in their first months of independent life, either before or after their first hibernation. Population densities vary with habitat type. Individuals may return to the same nest on consecutive nights or after a period of absence. Occasionally a nest will be used by first one and then another individual. Nest sharing (more than one hedgehog in the same nest at the same time) has been recorded only rarely in the wild, although it is relatively common in captivity. Hedgehogs are able to navigate well (e.g. returning to the same nest); it is likely that olfactory and auditory cues are most important although vision may play a role. (The detailed Literature Reports also include information on Methods of Marking and Following Hedgehogs) The provision of supplemental food appears not to affect the home range size or general behaviour of hedgehogs. The initial reactions of a hedgehog to danger include erecting their spines and if time permits running away from danger. However the main defence of hedgehogs in the face of a serous threat, particularly a disturbance involving physical contact, is to roll into a tight ball with spines bristling in all directions. Other defensive actions include hissing, screaming and (rarely, for example a female defending her young) biting. (Further information on curling mechanism in West European hedgehog Erinaceus europaeus - Detailed Physiology Notes (Literature Reports)) Hedgehogs possess a considerable protection against most predators of small mammals, in the form of their spines. However they are predated by badgers (Eurasian badger - Meles meles), foxes (Red fox - Vulpes vulpes), dogs, pine martens (Pine marten - Martes martes), pole cats (Polecat - Mustela putorius) and large birds of prey. Rats may prey on juveniles. Badgers appear to be important predators and the population size of hedgehogs in areas with large badger populations may approach zero; foxes may also affect hedgehog population size. When in deep hibernation hedgehogs may be vulnerable to being gnawed on by small rodents. Hedgehogs have relatively small brains but they are capable of highly flexible behaviour patterns and some individuals have been shown able to learn to distinguish between shapes and colours, and to respond to their name. (References are available in detailed literature reports below) |
| CLICK THE LINKS FOR Literature Reports | Literature Reports: West European hedgehog Erinaceus europaeus - Social Behaviour - Territoriality - Predation - Learning |
Sexual Behaviour |
|
| EDITORIAL SUMMARY | The following editorial comment
summarises detailed information given within the LITERATURE REPORTS. Links to the
LITERATURE REPORTS are provided at the bottom of this box. Both male and female hedgehogs show promiscuous courtship behaviour with no observed pair bonding. Courtship rituals are prolonged with the boar circling the sow while she erects her spines, snorts and even butts his flank. Quite commonly courtship behaviour does not lead to mating. When copulation occurs the sow crouches, raising the tail region and sometimes raising the forequarters (lordosis). The boar mounts from behind. (References are available in detailed literature reports below) |
| CLICK THE LINKS FOR Literature Reports | Literature Reports: West European hedgehog Erinaceus europaeus - Sexual Behaviour |
Activity Patterns, Self-grooming and Navigation |
|
| EDITORIAL SUMMARY | The following editorial comment
summarises detailed information given within the LITERATURE REPORTS. Links to the
LITERATURE REPORTS are provided at the bottom of this box.
ACTIVITY PATTERNS: Hedgehogs are predominantly terrestrial but they can both swim and climb well. It is thought that to descend from a height hedgehogs simply fall, using their spines to cushion the shock of landing. Hedgehogs are also able to dig and may make burrows for hibernation in some areas. They are able to squeeze through surprisingly small gaps when necessary. SELF-GROOMING: Hedgehogs use their hind claws for grooming and also lick areas of fur. A curious behaviour known as "self-anointing" may be seen when a hedgehog encounters a strong odour. This involves the hedgehog producing copious amounts of frothy saliva which it then distributes over its body. The purpose of this behaviour is still unknown, although many possible explanations have been put forward. CIRCADIAN RHYTHM: Hedgehogs are basically nocturnal. Hedgehogs may be seen active during daylight when demand for food is increased, for example lactating females and prior to hibernation. With these exceptions hedgehogs found out of their nest during the day are generally ill. SPEED OF MOVEMENT: Hedgehogs general move at speeds averaging about 3.7 metres per minute (males) or 2.19 metres per minute (females) but may move at speeds of about 30 m per minute for periods of several minutes, while speeds of 60 metres per minute and even 120 metres per minute have been recorded. NAVIGATION: It is thought that hedgehogs rely mainly on smell and hearing for navigation. (References are available in detailed literature reports below) |
| CLICK THE LINKS FOR Literature Reports | Literature Reports: West European hedgehog Erinaceus europaeus - Activity Patterns, Grooming and Navigation Behaviour |
General Habitat Type |
|
| EDITORIAL SUMMARY | The following editorial comment
summarises detailed information given within the LITERATURE REPORTS. Links to the
LITERATURE REPORTS are provided at the bottom of this box.
Hedgehogs range through habitats up to usually 400-600m and exceptionally 1,500-2,000 m above sea level. A wide variety of habitats are utilised including farmland, deciduous woodland, hedgerows, suburban gardens, urban parks etc. "Edge habitat" may be preferred. Large areas of arable monoculture with heavy pesticide use and lack of hedgerows are not useful habitat. Appropriate habitats contain sufficient invertebrate prey and nesting materials. (References are available in detailed literature reports below) |
| CLICK THE LINKS FOR Literature Reports | Literature Reports: West European hedgehog Erinaceus europaeus - General Habitat Type |
Nests / Burrows / Shelters |
|
| EDITORIAL SUMMARY | The following editorial comment
summarises detailed information given within the LITERATURE REPORTS. Links to the
LITERATURE REPORTS are provided at the bottom of this box.
Hedgehogs require nests throughout the year for concealment and for protection from the weather. Three different nests may be identified: day nests used during the summer when this nocturnal animal is sleeping, breeding nests used by sows and their litters, and winter nests or hibernacula. Winter nests are generally the most solid in construction. Nests are generally constructed in concealing and supporting vegetation but burrows (e.g. rabbit burrows) are sometimes used. (References are available in detailed literature reports below) |
| CLICK THE LINKS FOR Literature Reports | Literature Reports: West European hedgehog Erinaceus europaeus - Nests - Burrows - Shelters |
Distribution and Movement (Migration etc.) |
|
| EDITORIAL SUMMARY | The following editorial comment
summarises detailed information given within the LITERATURE REPORTS. Links to the
LITERATURE REPORTS are provided at the bottom of this box.
NATIVE DISTRIBUTION: This hedgehog is found in western and northern Europe and northern European Russia. Populations have expanded as far north as 66°N in Finland, and south to the northern coast of the Mediterranean. The eastern range is to about 40°E and overlaps with that of Erinaceus concolor - East European hedgehog. In Britain and Ireland hedgehogs are found extensively, including on many islands. Hedgehogs are basically sedentary. INTRODUCTIONS: Hedgehogs have been introduced to many British islands and to New Zealand, where they have been very successful. In some introduced areas they may represent a threat to native ground-nesting bird species by predation (particularly on eggs). (References are available in detailed literature reports below) |
| CLICK THE LINKS FOR Literature Reports | Literature Reports: West European hedgehog Erinaceus europaeus - Distribution & Movement |
Species variation |
|
| EDITORIAL SUMMARY | The following editorial comment
summarises detailed information given within the LITERATURE REPORTS. Links to the
LITERATURE REPORTS are provided at the bottom of this box.
Considerable variations have been recorded within Erinaceus europaeus. Several sub-species have been proposed based on various features including size and colouration. Some separations into subspecies is supported by studies of DNA. DNA data also support the separation of the West European hedgehog Erinaceus europaeus from Erinaceus concolor - East European hedgehog. There are some karyotypic differences (differences in chromosome size and arrangement) between hedgehogs from Britain and those from mainland Europe. (References are available in detailed literature reports below) |
| CLICK THE LINKS FOR Literature Reports | Literature Reports: West European hedgehog Erinaceus europaeus - Species Variation |
Conservation Status |
|
| EDITORIAL SUMMARY | The following editorial comment
summarises detailed information given within the LITERATURE REPORTS. Links to the
LITERATURE REPORTS are provided at the bottom of this box.
WILD POPULATION - IMPORTANCE: The West European hedgehog is not considered to have any global conservation problems. In Britain recent data from road kills, compared to data gathered previously, indicated that there may be a decline in the population, particularly in some areas. GENERAL LEGISLATION: There is some legal protection under the Bern convention (Appendix III), and the Wildlife and Countryside Act 1981 (Schedule 6) CITES LISTING: Not listed. RED-DATA LIST STATUS: Not listed. THREATS: Threats to hedgehogs include modern farming practices and over-tidying of parks, with associated loss of favourable edge habitat, use of pesticides particularly insecticides and molluscicides, traffic and locally badgers. Individual hedgehogs are at risk from many manmade hazards including bonfires, garden forks, strimmers, steep sided ponds etc. See: Garden Management for Hedgehogs (Erinaceus europaeus) for further information on man-made hazards and mitigation. PEST STATUS / PEST POPULATIONS: Hedgehogs predate eggs and chicks of ground-nesting birds. In the past this has led to persecution from gamekeepers although losses of gamebirds to hedgehog predation are minor. More recently, introduced hedgehogs have been implicated as threats to ground-nesting birds such as waders on British islands and in New Zealand. CAPTIVE POPULATIONS: Hedgehogs are sometimes kept as pets. Historically they have been maintained in laboratory colonies for experimental work e.g. on the physiology of hibernation, and on diseases. TRADE AND USE: Trade in this species is minimal. (References are available in detailed literature reports below) |
| CLICK THE LINKS FOR Literature Reports | Literature Reports: West European hedgehog Erinaceus europaeus - Conservation Status |