por The hedgehogs They are a group of spiny mammals that belong to the Erinaceinae subfamily. Its body, with the exception of its face, belly, and limbs, is covered in thorns. These structures are hard and hollow hairs that are formed by keratin.
They live in Africa, Europe and Asia, as well as being introduced to New Zealand. There are no native hedgehogs in Australia, nor are there living species native to America. In the regions where they live, they are usually forests, prairies, scrublands, hedges and deserts.
They are mainly nocturnal animals, sleeping for much of the day under grass, bushes, or rocks. However, most of the time they take refuge in their burrow, which they have generally dug in the ground.
To communicate, hedgehogs make a wide variety of sounds, including grunting, singing, and purring. When they are anxious, they can vocalize snorts and at the moment of eating they could grunt.
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Evolution
Hedgehogs are part of the Erinaceidae family. They are part of one of the most primitive groups of living mammals, characterized by presenting few anatomical and morphological changes during the last 15 million years.
Researchers, based on the fossil record, have discovered some of its ancestors. Among these are:
Litolestes and Leipsanolestes
Litolestes is the oldest known ancestor of modern hedgehogs. This lived from 65.5 to 56 million years ago, during the Paleocene. As for the Leipsanolestes, it is another genus that inhabited the same period. Their diet was based on insects.
Oncocherus
Fossils of the genus Oncocherus belong to the late Paleocene and were found in western Canada. It shares some characteristics with other primitive species that are members of the Erinaceidae family. One of these refers to the fact that both have enlarged lower and upper premolars.
cedrocherus
In addition to Leipsanolestes and Litolestes, the animals belonging to the genus Cedrocherus also lived in North America during the Paleocene. However, despite living in a common region at the same time, their teeth were possibly smaller.
deinogalerix
Deinogalerix was an animal native to Europe, which existed in the late Miocene, in modern Italy. Unlike modern hedgehogs, Deinogalerix lacked spines and had hair instead.
One element that it shares with primitive members of the Erinaceidae family is its insect-based diet.
General characteristics
Size
The hedgehog’s body can measure between 14 and 30 centimeters, while its tail tends to be 1 to 6 centimeters long. In relation to weight, it revolves around 397 and 1106 grams.
Immunity against snake venom
Like other mammals, such as rodents, the hedgehog has a natural immunity against snake venom. This is because your muscular system contains the protein erinacin, which prevents the action of said toxic substance.
In addition, like the mongoose, the hedgehog has a mutation in the nicotinic acetylcholine receptor that prevents the action of the α neurotoxin, present in snake venom.
thorns
The body is covered in spines, with the exception of the lower region, limbs, ears, and face. These structures are hollow hairs that are hardened with keratin.
The spines of the hedgehog have solid axes and represent about 35% of its total weight. In addition, they do not have spikes at their end, which can get stuck to the skin. The furrow in the animal’s forehead provides space for the spines in that area to stand up and point forward, rather than crisscrossing like those on the body.
Likewise, this animal does not release the spines, as does the porcupine. However, in the young they can fall off naturally, to be replaced by adult spines. In addition, these could come off if the animal is sick or under stress.
For the hedgehog, the spines are its main method of defense. When threatened, they raise them up and intersect, thus pointing in different directions. In this way, the body and skin are protected.
On the contrary, if the animal is relaxed, its spines are placed flat, facing the tail. If stroked from front to back, they will feel soft to the touch.
Teeth
The hedgehog has between 36 and 44 teeth, located in a long, pointed snout. The two central incisors are slightly longer than the rest. These do not grow constantly, as in rodents.
As for milk teeth, their molt occurs at an early age. They are replaced by adult teeth, which are rooted.
Body
The body is robust and its limbs are small and thin. As for their legs, they are devoid of fur. Both the male and female have a short, thick tail, which is usually hidden under the spines.
Coloration
The coloring of hedgehogs includes a wide range of shades. Some experts consider that there are more than 90 different colors.
This is why they have been grouped by categories, among which are: a) the standard (black or brown), b) the white with black eyes and c) those that have more than 90% white spines. There are also cinnamon (light brown to dark brown), snowflakes (less than 89% white spines), albinos and pintos, made up of those with spots.
Some spines can be striped, in black and white colors. Its belly, face and neck are covered in thick fur. The face is brown or white and they may have a dark brown or black mask over their eyes.
Taxonomy and classification
-Animal Kingdom.
-Subkingdom: Bilateria.
-Filum: Chordate.
-Subfium: Vertebrate.
-Superclass: Tetrapoda
-Class: Mammal.
-Subclass: Theria.
-Infraclass: Eutheria.
-Order: Erinaceomorpha.
-Family: Erinaceidae.
-Subfamily: Erinaceinae.
Genders:
-Atelerix.
-Paraechinus.
-Erinaceus.
-Mesechinus.
-Hemiechinus.
Habitat and distribution
Hedgehogs are distributed in Eurasia, Asia Minor, the Arabian Peninsula and in much of Africa and India. In New Zealand, it has been introduced as an exotic species.
Its natural habitats are highly diverse, including grasslands, forests, scrublands, pine forests, hedgerows, deserts, and savannahs. These regions provide the hedgehog with an environment with abundant food, protection from threats, and spaces to build their nests.
Each species develops in a specific area, where the environmental conditions are very particular. Thus, the Western European hedgehog (Erinaceus europaeus europaeus) lives in forest margins, scrublands, and grasslands.
On the other hand, the desert hedgehog (Hemiechinus aethiopicus) inhabits the arid Sahara and the Arabian peninsula, where it is concentrated around oases.
Pastures where sheep and cattle are raised are also an area where hedgehogs dwell. Likewise, they can abound in suburban and urban areas.
In recent years, gardens have provided a favorable area for resting, hibernating, and building nests for reproduction.
home ranges
Hedgehogs have home ranges, but are not territorial. Because of this, they will not fight with others to defend the space they inhabit. According to the studies carried out, the size of the area they occupy could vary during the year.
Within the limits of the space it inhabits, this animal builds its burrow underground, which it covers with leaves, flowers, and other plant material. To dig, it uses its sharp claws on its forelegs.
These nests could be up to 50 centimeters deep. They also tend to nest among rocks or take shelters that other mammals have left empty, such as rabbit and fox burrows.
State of conservation
Hedgehog populations are declining. This occurs as a consequence of the use of pesticides, the fragmentation of their habitat and indiscriminate hunting. These animals are captured to market some of their parts, which are used in traditional medicine.
This situation has caused the IUCN to categorize it as being of least concern about extinction. However, there are species that are seriously threatened.
Among these is the Shaanxi hedgehog, originally from China. Its population is threatened because it is hunted to be sold as food and as a base for some natural medicines.
The Daurian hedgehog (Mesechinus dauuricus) has lost its habitat in various regions of China, Russia and Mongolia. This is due to mining activities and poisoning from the use of rodenticides.
As for the Indian hedgehog (Paraechinus micropus), which lives in India and Pakistan, has disappeared from much of its range due to the expansion of farms into its desert habitat.
Reproduction
Hedgehog sexual maturity occurs when it is between 4 and 7 weeks old. Despite being a solitary animal, it forms a group during the reproductive process, in courtship and copulation, as well as when it has its young.
Before mating, the male performs a ritual, in which he surrounds the female that is in heat. This behavior could be carried out for a long time, until the female accepts it. After copulation, they separate, each heading to different areas.
Depending on the species, gestation can last between 35 and 58 days. During a year, it can raise up to 3 litters, each consisting of 3 or 4 young, in the largest species, and 5 to 6 in the smallest. However, on some occasions up to 11 young may be born in a single birth.
The babies
The young are born helpless and with their eyes closed. The body is covered with a protective membrane, which covers the spines. Its function is to prevent the internal organs of the mother from being injured at the time of delivery.
A few hours after being born, this integument dries up and shrinks, exposing the spines. These structures initially have a soft consistency, but between 3 and 5 days after being born, they are replaced by permanent ones.
It could be the case that the female eats some of the newborns, if she notices any disturbance in the nest. Similarly, the male could kill the young, a common behavior in many other animals.
https://www.youtube.com/watch?v=6zokydBV_Xc
From a very young age, hedgehogs can bend their bodies and form a ball. The western European hedgehog does so only when it is 11 days old. Depending on the characteristics of the species, the young can be suckled by its mother between 6 and 13 weeks.
Before the calf is separated from the mother, they go on exploration trips together to explore the environment where they live. If a youngster strays too far from the mother, she can whistle, with the intention that she can locate him.
Feeding
The hedgehog’s diet is varied, but a high percentage of it is made up of insects. Their prey includes a great diversity of invertebrates, such as snails, slugs, and spiders.
It also tends to eat carrion and some