''Erinaceus'' is a genus of
hedgehog
A hedgehog is a spiny mammal of the subfamily Erinaceinae, in the eulipotyphlan family Erinaceidae. There are seventeen species of hedgehog in five genera found throughout parts of Europe, Asia, and Africa, and in New Zealand by introductio ...
from the family of
Erinaceidae. There are four main species of ''Erinaceus''. The range is all across Europe, throughout the Middle East, parts of Russia, and extending to northern China and Korea. The European hedgehog (''Erinaceus europaeus'') has been introduced to New Zealand.
[Macdonald, David W. The Encyclopedia of Mammals. New York, NY: Facts on File, 1984 .]
Description
As is characteristic of other hedgehogs, members of ''Erinaceus'' have spines. These spines are a modification of the hair that is formed and strengthened by
keratin
Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. Alpha-keratin (α-keratin) is a type of keratin found in vertebrates. It is the key structural material making up scales, hair, nails, feathers, ho ...
. They contain hollow air filled gaps separated by thin inner layers of the spine to lessen the weight load.
[Grzimek, Bernhard, Neil Schlager, Donna Olendorf, and Melissa C. McDade. Grzimek's Animal Life Encyclopedia. Vol. 13. Detroit: Thomson Gale, 2004.] Every spine is tapered at the end to form a point and also at the base where it then forms a bulb that is attached to the skin. The tapering at the base allows the spine to have a section that will bend under stress and dampen forces placed on the spines. Each of the spines has a dermal muscle that erects the spine for defense.
The size of ''Erinaceus'' is 20–30 cm with a weight of 400–1200 g.
[Lal, S. S. Practical Zoology Vertebrate. Meerut, IN: Global Media, 2010.]
Behavior
Like all other hedgehogs ''Erinaceus'' is
nocturnal
Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite.
Nocturnal creatures generally have highly developed sens ...
and seeks shelter in shrubs and burrows during the day.
[ Qumsiyeh, Mazin B. Mammals of the Holy Land. Lubbock: Texas Tech UP, 1996 .] The common defense mechanism is to roll into a ball with the spines facing outward. The action is done because of excess loose skin on the back of hedgehogs allows them to pull it around the rest of their body forming a ball. The first step is to pull skin fold over the head and rear of the body. Once this is done a muscle that runs along the edges of the animal called the ''panniculus carnosus'' contracts pulling everything in like a drawstring.
Like most hedgehogs ''Erinaceus'' is solitary until breeding season. Another normal action is self-anointing where the organism produces thick foamy saliva and proceeds to cover its spines with the saliva. This could be in response to a chemical signal and often is done when a new object is introduced. The reason for self-anointing is unknown and believed to be either part of a defense or attraction of a mate.
Hibernation is common in each of the species for ''Erinaceus''. Most have the ability to lower the body temperature close that of the environmental temperature. In particular ''
Erinaceus europaeus
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.Harris, S. ...
'' the body temperature can drop down to 1 °C and lower its heart rate down to 22 beats per minute.
Reproduction and lifespan
It is believed that ''Erinaceus'' is
polygynous in mating. Once fertilized
gestation
Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during pregna ...
is between 30–40 days. Upon birth the young are born blind and dependent to their mother. The average litter size is 2–5 offspring with a maximum of 10. Offspring are born without developed spines, which form within a few weeks. Weaning occurs around 4–6 weeks. Sexual maturity is reached around 12 months. The average life span is 2–5 years while in captivity lifespan can reach as much as 10 years.
Diet
''Erinaceus'' is an
omnivore
An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nutr ...
. It will eat small invertebrates, small vertebrates, fruit, vegetables, and even fungi. In some cases they have been known to eat venomous snakes or even toxic beetles. Some species show resistance to snake venom up to forty times greater than that of the ordinary laboratory mouse.
Species
References
{{Taxonbar, from=Q498993
Hedgehogs
Mammal genera
Taxa named by Carl Linnaeus