Erinaceidae

Long- eared Hedgehog ( Hemiechinus auritus )

The Hedgehog ( Erinaceidae ) constitute a family of mammals whose best known representative of the species living in Europe Hedgehog (Erinaceus europaeus) and the Northern White -breasted Hedgehog (Erinaceus roumanicus ) are. Overall, the family includes about 25 species that are widespread in Eurasia and Africa. They are divided into two externally significantly different subfamilies, the hedgehog ( Erinaceinae ) and the stingless rats or hair hedgehog ( Galericinae ). The systematic position of the hedgehog is still controversial: It discusses one belonging to the insectivores ( Eulipotyphla ) or a position in their own order ( Erinaceomorpha ) on the basis of the higher mammals ( Eutheria ), with recent studies can be re likely the former variant.

• 4.1 General
• 4.2 Social behavior and activity times
• 4.3 Dining
• 4.4 Reproduction

• 6.1 Outer systematics
• 6.2 Internal systematics
• 6.3 phylogeny

Etymology

Old High German igil ( 9th century ), Middle High German hedgehog, Old Saxon igil, Middle Low German ule, medium dutch Eghel, Dutch ule, Old English igil, Old Norse īgull is, as l - derivative related to the Greek Echis ( ἕχις ) ' snake ', from Indo-European * eĝhi - ' snake '.

At the same Greek or Indo- output form with n- suffix include Greek echinos ( έχΐνος ) ' hedgehog, sea urchin ' and Indo-European io- suffix: Serbian Church Slavonic ježь, Russian ёж, Lithuanian ežys ' hedgehog '.

All these derivatives are as ' snake animal, snake -eater ' to understand, as the hedgehog eats except insects, frogs, mice, snakes etc..

Features

General Body

Hedgehogs are small to medium sized animals. Your head-body lengths vary from 10 to 45 centimeters. The hedgehog - type with the largest and heaviest specimens is the Great Rat Hedgehog with a weight of up to 2 kg. In contrast, bring copies of the Little Hedgehogs Rats 20 to 80 grams on the scale. The tail length of hedgehogs is variable, some representatives of the rats hedgehogs have a long tail, as he usually is only a short stub at the sting hedgehogs.

The limbs of the hedgehog are relatively short and unspecialized. The thumbs or big toes are not opponierbar as with all insectivores, the feet end in usually five toes equipped with sharp claws - only the African hedgehogs have four toes on the hind feet. The tibia and fibula are fused as in many insectivores in the bottom half.

Hedgehogs are plantigrade. In rats, hedgehogs, the hind legs are slightly longer than the front legs to allow rapid escape.

Hair dress

The fur of the hedgehog is usually held in inconspicuous brown or gray tones. The hedgehog have an effective defense weapon spines on the back and the flanks ( the Hedgehog is about six to eight thousand ). These spines are modified, hollow hairs. Each sting is equipped with a Aufrichtemuskel ( arrector pili muscle ). Hedgehog can roll up into a ball in the case of threat. The curling of the body is a complex interaction of many muscles, including the musculus caudo - dorsal, extending from the caudal vertebrae to the spine and the spines erect, and a sphincter ( sphincter cuculli ) holding closed the ball and so the unprotected parts of the body conceals. The belly, the face and the limbs are covered in the sting hedgehogs with fur.

In contrast, rats hedgehogs have no spines and bring about ( and mostly due to the longer tail ) a more shrew -like impression. Your gray brown to black fur can be silky smooth or rough depending on the type. The defense strategy of these animals will escape.

Head and teeth

The skull of the hedgehog is elongated and flat. A special feature is the closed zygomatic arch and the independent zygomatic what these animals differs from most other insectivores. The head sits on a short neck. The long, flexible snout is equipped with whiskers. The eyes and ears are - compared to other insectivores - relatively large. The sense of smell and hearing are probably the most important senses in search of food, the sense of sight, however, plays only a minor role.

The braincase is relatively small, therefore the brain is simply constructed and compared to body mass small. The olfactory bulb, however, is well developed. Even the Hedgehog uses the Jacobson's organ.

The teeth of the hedgehog are provided with pointed cusps and sharp melting strips and very well adapted to their carnal diet. All species have a comparatively large teeth, with some representatives of the original tooth number has survived 44 of the Higher mammals. The foremost incisor is often larger than the other incisors, upper molars have four cusps, the posterior molar tooth is often reduced.

Digestive and reproductive tract

The digestive tract is built very simple. There is no cecum, the colon is a simple tube, and compared with the body length is very short. In the males, the testes are always outside the abdominal cavity in scrotum -like skin folds, the Cremaster wrinkles. The females have a bicornuate uterus.

Distribution and habitat

Hedgehogs are restricted to the Old World, they are found in Europe, Africa and parts of Asia. In America they are absent, as in Australia. While extending the range of the hedgehog from the British Isles and the Iberian Peninsula to South Africa or Korea and India, the rats hedgehogs are limited to Southeast Asia.

Hedgehogs inhabit a variety of habitats: The Hedgehog prefer dry habitats, they found, inter alia in light forests, grasslands and cultivated landscapes. Some genera, such as the deserts and long-eared hedgehogs are even pronounced steppe and desert dwellers. The rats hedgehogs, however, prefer moist habitats and are found primarily in rainforests.

No hedgehogs and not closely related to them, however thorn bearing insectivores are the Echidna.

Way of life

General

Hedgehogs are primarily terrestrial ( ground- living). While some species can climb well and keep up sometimes on bushes on, but usually they are looking at the ground for food. Some species lay for faster progress on trails in the dense undergrowth. Some species can swim well. At least one kind, the Great rats hedgehogs, also goes in the water in search of food.

The Hedgehog usually dig their own burrows, which they serve as resting places. The entrances of the burrows are usually hidden in dense vegetation, the nest is often lined with dry vegetation. In contrast, the rats hedgehogs lay mostly not Build on, but hidden between crevices in tree trunks or in burrows.

Hedgehog curl up into a ball at risk and align their spines (see coat ).

Social behavior and activity times

Hedgehog lead outside the mating season usually a maverick life. They are predominantly crepuscular or nocturnal, only of some species of rats hedgehog is known that they can go during the day in search of food.

The hedgehog in colder climates hibernate, the residents very hot areas covered during the dry periods in a torpor (rigid state).

Food

The food of the hedgehog consists primarily of invertebrates (eg, insects and their larvae and annelids ), but they also take small vertebrates and carrion to himself. On a small scale, they also eat plant material such as roots and fruits.

It is wrong to claim that hedgehogs store their food supplies on the spines. Although sometimes leaves or fruits found impaled on her back, however, the animals eat not thereof. Take this ballast unwittingly, for example, in her nest, and then seem to attach no great zeal in its removal.

Reproduction

Hedgehog bring once ( in warmer regions also twice) in offspring born. After a 30 - to 48 - day gestation, the female gives birth to one to eleven pups ( at the European species are there on average four to five). Newborns are initially blind and helpless. The young hedgehog who at birth is still soft spines, so as not to injure the birth canal of the mother. After 12 to 24 days the young open their eyes, after six to eight weeks they are weaned. Sexual maturity usually occurs after 6 to 12 months. Life expectancy in the wild is - if known - three to seven years.

Hedgehogs and humans

From a national medical or superstitious reasons, some hedgehog species were hunted, but not to an extent that threatened the entire population. White-bellied dwarf hedgehogs kept as pets in some places, mostly in the U.S., but now already in Europe. After many animals were originally imported, originate most today from captive bred and are already available in different color shades.

Since the Hedgehog Culture followers are to some degree or often inhabit dry, sparsely populated regions, they are less at risk than other mammalian species. In contrast, the regenwaldbewohnenden rats hedgehogs are exposed to the threats associated with the destruction of their habitat. The IUCN lists two species of hedgehog rats as " critically endangered " ( endangered ), an 'at risk' ( vulnerable ), for another type lacked data.

Since most of the cultural references of the Hedgehog limited to the common European Hedgehog, reference is made at this point to this article.

System

Outer systematics

The systematic position of the hedgehog is one of the most controversial issues in the classification of mammals. For a long time they were ranked in the order of insectivores ( Insectivora ), to include, among other things, shrews and moles. This order was, however, defined only by relatively weak similarities, again and again groups have been extended or divided.

Since the beginning of the 21st century, there were few molecular genetic studies, such as mitochondrial genes, according to which the hedgehogs are not closely related to the other insectivores, but a separate order ( Erinaceomorpha ) form. These studies placed the hedgehog on the basis of the higher mammals and saw them as the sister group of all other higher mammals.

However, there is criticism of these studies. Especially mitochondrial DNA sequences have undergone a rapid evolution with a high mutation rate in these animals and therefore differ genetically more from their nearest relatives as these from more distant species. Subsequent analyzes, among others, by nuclear genes, and mitochondrial genes in turn confirmed the affiliation of the hedgehog to the insectivores. Even though this view is not without controversy, but it gains more and more evidence.

According to these studies, the closest relatives of hedgehogs are the shrews, within the insectivores thus leads to the following cladogram:

Talpidae ( moles )

Erinaceidae (hedgehog )

Soricidae ( shrews )

Solenodontidae ( Solenodon )

Nesophontidae † (Caribbean shrews )

Inside systematics

The hedgehogs are divided into two subfamilies with 10 genera and 25 species:

• Rats hedgehogs ( Galericinae ) Big rats hedgehogs ( Echinosorex Gymnura )
• Small rats hedgehogs ( Hylomys ), three types
• Shrew hedgehog ( Neotetracus sinensis)
• Hainan rats hedgehogs ( Neohylomys haina sensis )
• Philippines rats hedgehogs ( Podogymnura ), two types

• Small eared hedgehog (Erinaceus ), four species ( including the two surviving representatives in Europe )
• African hedgehog ( Atelerix ), four types
• Steppe Nigel ( Mesechinus ), two types
• Long- eared Hedgehog ( Hemiechinus ), two types
• Desert Nigel ( Paraechinus ), four types

Phylogenetic relationships within the family are expressed in the following diagram:

Small rats hedgehogs ( Hylomys )

Hainan rats hedgehogs ( Neohylomys )

Shrew hedgehog ( Neotetracus )

Big rats hedgehogs ( Echinosorex )

Philippine rats hedgehogs ( Podogymnura )

Short-eared hedgehog (Erinaceus )

African hedgehog ( Atelerix )

Steppe Nigel ( Mesechinus )

Desert Nigel ( Paraechinus )

Long- eared Hedgehog ( Hemiechinus )

Phylogeny

The fossil history of the hedgehog goes back to the Paleocene, when her oldest known representative shall Litolestes from North America. From North America and Europe, the group of Amphilemuridae is known, which already had very similar defense strategies as today's representatives. From the Miocene of Europe, the genus Deinogalerix known, a representative of the rats hedgehogs, who probably weighed about ten pounds. In the Pliocene, the Hedgehogs in America are likely to be extinct.