History of... Hedgehogs

Name: Hedgehog
Scientific Name: Erinaceinae 
Family: Erinaceomorpha
Conservation Status: Least Concern

Habitation:
Woodlands, dense vegetation, suburban areas

Global Location:
Europe, Asia, Africa, New Zealand

Discovery:
Hedgehogs have been around for over 15 million years and are Thought to be one of the oldest mammals on Earth!

There are seventeen species of hedgehog. They share distant ancestry with shrews and have changed little over the last fifteen million years. Like many of the first mammals, they are nocturnal.

They generally live between 2 and 7 years in the wild, in captivity where there are a lack of predators and more abundant diet, they can live to 8 to 10 years.

The name hedgehog came into use around 1450, derived from the Middle English heyghoge, from heyg, hegge (hedge), because it is often spotted around hedgerows, and hoge, hogge (hog), from its pig like snout. Other names include urchin, hedgepig and furze-pig.

Hedgehogs are easily recognized by their spines, which are hollow hairs made stiff with keratin. Their spines are not poisonous or barbed. Hedgehogs are usually brown, with pale tips to the spines.

A hedgehog can defend itself by rolling into a tight ball to protect their face, feet and belly, which do not have spines. The hedgehog's back contains two large muscles that control the position of the quills.

Hedgehogs are nocturnal, though some species can also be active during the day. They sleep for a large portion of the day under bushes, or in dens dug into the ground. All hedgehogs can hibernate, though not all do as it depends on temperature, species, and abundance of food.

Hedgehogs are fairly vocal and communicate through a combination of grunts, snuffles and/or squeals.

Like opossums, mice, and moles, hedgehogs have some natural immunity against some snake venom through the protein erinacin in the animal's muscular system, although it is available only in small amounts and a bite may still be fatal.

Hedgehogs feed on insects, snails, frogs, toads, snakes, bird eggs, carrion, mushrooms, grass roots, berries, melons and watermelons.

During hibernation, the body temperature of a hedgehog can decrease to about 2 °C (36 °F).

When they wake up from hibernation, their body temperature rises from 2–5 °C (36–41 °F) back to its normal 30–35 °C (86–95 °F) body temperature.

The gestation period is 35 to 58 days and have around 3 to 6 young. The young can go foraging with the adults at around 3 to 4 weeks old and become mature at around 9 to 11 months old. This can vary depending on the species.

The main natural predators to hedgehogs are birds (especially owls) and ferrets, foxes, wolves, badgers and mongooses. Hedgehog bones have been found in the pellets of the European eagle owl.

Hedgehogs are a food source in many human cultures. They were eaten in Ancient Egypt and some recipes of the Late Middle Ages that listed hedgehog meat in the ingredients.
They are traded throughout Eurasia and Africa for traditional medicine and witchcraft. In the Middle East hedgehog meat is considered medicinal.

In 2022, it was reported that the hedgehog population in rural Britain is experiencing a rapid decline, going down by 30%-75% since 2000.

Hedgehogs suffer many diseases common to humans. These include cancer, fatty liver disease, and cardiovascular disease. Hedgehogs are also known to be highly susceptible to pneumonia. Similarly to how pneumonia affects humans, the symptoms for pneumonia in hedgehogs include difficulty breathing and presence of nasal discharge.

Hedgehogs uncommonly transmit a fungal skin infection to humans that handle them.

Hedgehogs can suffer from balloon syndrome, a rare condition in which gas is trapped under the skin as a result of injury or infection and which causes the animal to inflate.

As with most small mammals living around humans, cars pose a great threat to hedgehogs. Many are run over as they attempt to cross roadways. In Ireland, hedgehogs are one of the most common road fatalities.

There were significantly more males than females collected, with peaks in male deaths occurring in May and June.
Female deaths outnumbered males only in August, with further peaks in female deaths in June and July.
It is suggested that these peaks are related to the breeding season (adults) and dispersal/exploration following maturity.