Atelerix

Diversity

Atelerix includes four species, Atelerix albiventris , Atelerix algrius , Atelerix frontalis , and Atelerix sclateri . All of these species are natives to Africa and are polygynous. They produce between two and five young. They have short life spans of about three years. They are omnivorous and their biggest predator is humans and other carnivores. These species can be kept as pets by humans but can infect humans with diseases by either directly handling them or by having contact with the soil in which these animals burrow in. The members of this genus are considered not threatened.

Geographic Range

African hedgehog species can be found throughout their native homeland of Africa. North African hedgehogs are found in North Africa in the African tropics including the Canary Islands. Southern African hedgehogs are located in South Africa near the Niger River. Four-toed hedgehogs are also located in the African tropics but mostly appear in the northern Niger area. They are also encountered in savanna and steppe zones and are considered natives to many countries in Africa.

• Biogeographic Regions
• palearctic palearctic
  • introduced introduced
• ethiopian ethiopian
  • native native

Habitat

On the Canary Islands, North African hedgehogs are mostly found in agricultural habitats. They are invasive non-natives to the Canary Islands which are considered to be a semiarid habitat. In lower altitudes these islands can get up to 300 millimeters of precipitation annually and their average temperature is about 21 degrees Celsius (70 degrees Fahrenheit). In higher altitudes the annual precipitation rises to a maximum of 800 millimeters and the average temperature is about 9 degrees Celsius (48 degrees Fahrenheit). In general, though this species is only found on four of the Canary Islands. Two of those four are low in altitude and are influences by dry winds. Each island has a different habitat full of different kinds of vegetation and animals depending on their altitude and amount of rain fall.

Four-toed hedgehogs are found in a terrestrial habitat, inhabiting steppes, savannas, and grasslands. This species is also widely spread throughout Africa but is sporadic in drier regions. They can also be found in contact with humans by living in gardens and plantations. They mostly live in areas with dry soil and are not found in forests. They require dry shelters in grass, leaf litter, a rocky crevice, or a hole in the ground. They are mostly known to live in areas where they can sleep in buildings or in brushwood. They prefer to live in open, dry, or seasonal habitats with sparse or patchy grass cover. This is important because they prefer to not live with large populations of ungulates.

• Habitat Regions
• tropical tropical

• Terrestrial Biomes
• savanna or grassland savanna or grassland

• Other Habitat Features
• suburban suburban
• agricultural agricultural

Systematic and Taxonomic History

Before Atelerix was elevated to the genus level by Pomel in 1848, species in this genus were considered Erinaceus . There are two generic synonyms: Aethechinus and Peroechinus .

Four-toed hedgehogs were named in 1841 and heir type locality was in 1939. They have multiple synonyms, including Atelerix dansoni , Atelerix langi , Atelerix pruneri , and Atelerix faradjius .

North African hedgehogs were named in 1842 and it was discovered that even though the credit for the name was originally listed by two authors, only one of those was the real author. This species has three subspecies: Atelerix algirus algirus , Atelerix algirus girbanensis , and Atelerix algirus vagans . The last two subspecies were recognized in 1983. This species has no synonyms.

Southern African hedgehogs were named in 1831. This species does not form a monophyletic group with the other species of Atelerix and may be considered in its own genus. There are two subspecies: Atelerix frontalis frontalis and Atelerix frontalis angolae . In 1986 Atelerix frontalis angolae was classified as a valid subspecies. There are no synonyms for this species.

Somali hedgehogs which were discovered and named in 1895. Not much is known about this species except that it is closely related to four-toed hedgehogs and might actually be just a subspecies. As a result there are no listed subspecies or synonyms.

Physical Description

African hedgehogs are small animals with short legs and large feet. They have four digits on their front feet. They walk with a flat-footed “plantigrade” gait and have their tibia and fibula fused into one. They have hairy tails and elongated muzzles. They also have small eyes and a small braincase. They have a dense coat of narrow spines that start at their head and cover their back.

African hedgehogs range in body length from 5.5 inches to 10 inches and they weigh on average between 10.5 ounces and 17.5 ounces. Their tails range from a length of 0.8 inches to one inch. Overall, they all vary in looks, four-toed hedgehogs have a very pale, almost white, face and the underparts. The only variation between males and females of four-toed hedgehogs is that males have numerous elongated white spines that are usually absent in the females. They are gray brown to fizzled black when it comes to their fur and spines, just like southern African hedgehogs and Somali hedgehogs . North African hedgehogs are slim with brown fur and short spines. Somali hedgehogs have a white belly with dark fur on their lower abdomen and unlike the other species, they have a big toe. All African hedgehog species have a prominent white band from their forehead to flanks and also have a narrow center parting in their spines on their forehead.

• Other Physical Features
• endothermic endothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• sexes alike

Reproduction

African hedgehogs are polygynous, one male lives and mates with multiple females. Males take no part of caring for the young, they play part in courtship and mating. Females advertise for a mate with a whine. Males then court females by persistently following them. Males walk around females in estrous with their snout pointed toward her, making puffing sounds sometimes for several days. Females vigorously butt males with their heads as they snort and reject him. Males mount females from behind after she has flattened her spines and pressed her hindquarters out.

Four-toed hedgehogs are sexually active throughout the year with no apparent mating season. They average about one litter a year. Ovulation is induced by exposure to a male and normally occurs 16 to 23 hours after mating. The hormone gonadotropin is released and acts on the testes and ovaries to initiate and maintain their reproductive functions. Once that hormone is released about seven to eight eggs are ovulated. The length of time between initial introduction of a male and birth is between 34 and 44 days. Detecting pregnant hedgehogs is difficult but females can be assumed to be pregnant if they gain a significant amount of weight in two weeks. Females nutritional needs during pregnancy and lactation are about three times as great and caloric needs can increase five to six times.

• Mating System
• polygynous polygynous

African hedgehogs have a gestation period ranging between 30 and 40 days. They can produce a maximum litter size of ten, but typically have two to five young per litter. Young can be born during any month of the year for four-toed hedgehogs . Southern African hedgehogs have a gestation period lasting 35 days. They have birth peaks from October to March.

Males have a penis with a smooth surface that has no spines. The penis is in a low pelvic position within the abdomen and has “horned” glans. Their spermatozoa have an asymmetric insertion of the tail on the sperm head. So far it is not understood why the spermatozoa is this way, but it is not unique to this genus. The spermatozoa also have a perforatorium with lateral barbs. The acrosomal matrix consists of only two peptides. Males also have testicles that remain intra-abdominal throughout their life.

Females have compact cumulus cells with very little matrix and is resistant to hyaluronidase in the freshly ovulated state. The diameter of the oviduct ampulla is not spacious, hardly exceeding that of the isthmus. They are considered an induced ovulator.

When neonates are born, males and females all appear similar. Within 24 hours after birth the preputial opening of males migrates to the middle of the abdomen. For females the vulva is only a few millimeters from the anus.

• Key Reproductive Features
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• viviparous viviparous

African hedgehog young are born blind, helpless, and virtually naked so they are cared for by their mothers only. Females lick their young, eat the afterbirth, and place the young on their stomach to suckle. Young actively and vigorously push at the mother to search for a nipple and feed in the prone position to avoid injuring the mother while feeding. Before the eyes of young are open, they suckle solely from pectoral nipples. After they open their eyes, they suckle from both abdominal and pectoral nipples. The suckling period for them is between five and seven weeks. Young are weaned by four to six weeks of age and typically leave the mother in 30-45 days after that.

Southern African hedgehogs become mature at nine to ten weeks old. Four-toed hedgehogs usually reach sexual maturity at about one year old.

• Parental Investment
• female parental care female parental care

Lifespan/Longevity

African hedgehog species live between two and three years in the wild. They can survive up to ten years in captivity.

Behavior

African hedgehog species are nocturnal and solitary. They aestivate from June to September in South Africa. However, it is unlikely that they will in Nigeria. Aestivating means that they spend a hot or dry period in a prolonged state of dormancy. In order to aestivate they need to have a thick fat reserve for them to live on.

When African hedgehogs are threatened, they curl up into a spiny ball to protect their heads and ventral surface. They growl, snort, and butt heads with other individuals when approached. They engage in self-anointing behavior, they spread odoriferous substances over themselves. One example of this is that they will take venom secretions from toads into their mouth and spread it over their spines. This would likely increase pain or potential infection of a potential predator. The reasoning for this behavior is unknown but it could be related to courtship or as a way for young to get their mother’s attention. This behavior could also be a way of protecting themselves against possible predators. They are terrestrial but are able to climb and swim. Africans hedgehogs move slowly but are capable of bursts of speed.

In captivity, a social hierarchy is formed. Males fight and injure each other when they are held in close conditions in captivity. A defense behavior has been observed in captivity and not in the wild. In this behavior they erect their spines over the head and lunge toward the predator.

Courtship happens immediately when they are in captivity. Courtship normally includes various noises and nipping of the spines and feet. Pregnant females should be kept separately from others because cannibalization of neonates might occur. Females also are protective of their young and attack humans who disturb them. Sometimes females reject their young, kill them, or even eat their young if they have been handled by a human. It is suggested to leave mothers alone with their young one to two weeks after birth.

• Key Behaviors
• nocturnal nocturnal
• motile motile
• aestivation
• solitary solitary

Communication and Perception

Members of African hedgehogs create a twitter vocalization with a closed mouth that can be heard at a distance of 20 centimeters. Both sexes make this twitter noise but those that are younger than 3 months and some adults never make this noise. This genus also makes hisses and snorts as a form of communication. They scream when they are attacked. Males serenade females with a birdlike call and females respond with hisses, snorts, or evasive movements.

• Communication Channels
• acoustic acoustic

• Perception Channels
• tactile tactile
• chemical chemical

Food Habits

African hedgehog species are omnivorous. They eat invertebrates and small vertebrate prey. Vertebrate prey includes beetles , earthworms , frogs , small reptiles , termites , rodents and birds’ eggs. They also eat fruit and fungi. These hedgehogs will also eat road kills at night.

Prey is located by sight, scent and sound and can be located four centimeters deep in soil. When hunting, they move their spines forward over the nose, which allows for a small about of exposed area. Immobile foods are often toyed with before they are consumed, and active prey is snapped into the mouth and chewed noisily. They shake their prey to death before being consumed.

• Primary Diet
• omnivore omnivore

Predation

A significant predator of African hedgehogs is humans, who kill hedgehogs through road kills. Road kills are highest in spring and summer.

Four-toed hedgehogs have been found in pellets of the Verreaux’s eagle-owl . These eagle-owls are capable of killing them with their talons, despite their spines. Other carnivores prey on these animals, including species of owls , honey badgers , jackals , hyenas , and domestic dogs .

Ecosystem Roles

Helminths and parasitic worms are found in Algerian hedgehogs . The most common type found is Physaloptera clausa which uses Algerian hedgehogs as an intermediate host. Four-toed hedgehogs can carry ringworm .

Economic Importance for Humans: Positive

African hedgehogs are kept as pets by humans. They are a good food source for people. They are beneficial when it comes to being a predator of invertebrate pests.

• Positive Impacts
• pet trade pet trade
• food food
• controls pest population

Economic Importance for Humans: Negative

Four-toed hedgehogs can infect humans with diseases through direct physical contact with them or contact with the soil in which these hedgehogs burrow in. These diseases are bacterial, arboviruses, or parasitic. They are vectors or hosts for mange in humans and play a role in transmitting salmonella tilene, which is a rarely encountered serotype of humans. This means that the disease affects the immune cells of humans.

• Negative Impacts
• injures humans
  • causes disease in humans causes disease in humans
• causes or carries domestic animal disease causes or carries domestic animal disease

Conservation Status

Southern African hedgehogs are not officially listed as threatened. They are listed as rare in South Africa and suffer from localized hunting and collecting. They suffer from habitat loss due to agricultural development.

Other African hedgehog species are listed as not threatened. Four-toed hedgehogs are classified as “lower risk- least concern”. They are common in their habitat but rarely seen and are not distributed throughout their range in eastern Africa.

Other Comments

There has been some fossil record analyses that have determined that the Erinaceidae family, that includes the genus Atelerix, has been around since the Late Cretaceous period. This family was more widespread in Africa during the Miocene and contained nearly 40 extinct forms in the superfamily Erinaceodea. North African hedgehog fossils have been identifited in a Bronze Age gravesite on the island of Minorca. No four-toed hedgehog fossils have been found.

African hedgehogs have a diploid number of 48 chromosomes. Their third largest chromosome is a sex chromosome. What makes this genus separate from the family Erinaceus is that they have an absence of positive heterochromatic material, a grouping of 3 small autosomal pairs, and absence of a medium-sized acrocentric element that happens to be present in Erinaceus. Atelerix and Aethechinus have similar genetic material and it has previously been proposed to merge these two taxa into a single genus. That proposal was rejected in 1985 but has since gained acceptance in 1986, 1991, and 2005.

Additional Links

Encyclopedia of Life

Contributors

Danielle Mumaw (author), Colorado State University, Tanya Dewey (editor), University of Michigan-Ann Arbor.

References

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Deef, L. 2019. First Record of Atelerix albiventris (Family: Erinaceidae) from South-Eastern of Egypt Confirmed by Molecular Analysis.. Pakistan Journal of Zoology , 51/1: 9-14. Accessed February 01, 2020 at http://apps.webofknowledge.com.ezproxy2.library.colostate.edu/full_record.do?product=ZOOREC&search_mode=GeneralSearch&qid=58&SID=8B5MhTd9TPb42aSVxDc&page=1&doc=7 .

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