Introducing Hedgehog

African Pygmy Hedgehog (Atelerix Albiventris)

Hedgehogs have been around for the last 15 million years share a distant similarity to shrews (family Soricidae) and does not experience any significant changes since then. It belonged in the Erinaceinae subfamily in the eulipothyplan family Erinaceidae. Seventeen species of hedgehog are discovered through parts of Europe, Asia and Africa. New Zealand however, is an area where hedgehogs does not originally belong to and can only be found in the region after introduction. Hedgehogs are not native to Australia and other than the already extinct Amphechinus genus, no other hedgehogs are species native to the Americas.  

Their spiny protruding spines or quills are technically hairs made stiff with keratin. Contrary to general belief, hedgehog spines are not poisonous or barbed and unlike porcupines, do not detached easily from their bodies. Quills detachment only occurs during “quilling”. Like shedding, quilling is a process where the immature spines fall out as they are replaced with stronger, adult spines. It can also occur when a hedgehog contract disease or under extreme stress. 

European Hedgehog (Erinaceus Europaeus)

Skeletal System of a Hedgehog

All species of hedgehogs possess ability to roll into a tight ball as a defensive manoeuvre. This caused their spine to roll outwards. This is enabled by two large muscles that spans along the back of a hedgehog. When the creature rolls into a ball, its body, feet and belly is tucked inside the outside layer of quills. This helps hedgehogs to protect themselves from imminent danger from predators; forest hedgehogs are prey to carnivorous birds and ferrets while smaller species are often hunted by foxes and wolves. Since hedgehogs often spend most of their time on trees away from the ground, it rolls into a ball and jump towards the ground in the event of an attack. Their quills absorb the impact of the fall as the body touches the ground. This is the aspect that is deemed unique for a hedgehog and will be the subject for this research. 

Other unique characteristics that hedgehogs have include: 

• PRIMARILY NOCTURNAL. Some species can be found sleeping throughout large portion of the day under bushes, grass or dens dug in ground. Depending on the temperature, species and food abundance, wild hedgehogs can enter themselves into hibernation. 
• FAIRLY VOCAL. They communicate through grunts and squeals depending on species. 
• ANNOINTING RITUAL. As it encounters a new scent, it will lick and bite the source. A scented froth the formed in its mouth and is pasted on its spine using its tongue. This is believe to camouflage the hedgehog from the predators in the area and to some cases, generating a poison that can be used to infect predators that are poked by it spines.  
• NATURAL IMMUNITY TO VENOMS. Hedgehogs, among opossums, mice and moles, have some degree of immunity against some snake venom. This is made possible due to the protein erinacin in the animal's muscular system. However, it is only available in small amounts and viper crushing bite might still be fatal. In addition, hedgehogs contain mutations in the acetylcholine receptor that prevents binding against another snake venom, α-neurotoxin.