The European Hedgehog

Latin Name: Erinaceus europaeus.

Named so because of their pig-like behaviour- rooting around in the undergrowth when foraging for food.

Weight & Length:

Weight and length will vary depending on the gender of the Hedgehog and its age. An adult Hedgehog ranges in length from around 24 to 35 cm and 9 ½ to 14 in. The weight of a Hedgehog has a huge range, and an healthy adult Hedgehog can weigh from 500g to just over 1kg. Hedgehog aim to put on as much weight as possible in Autumn, for Hibernation. This means that they will weigh alot more at that time of year. 

Life Span: Up to five years

Full Description:

Hedgehogs have a shiny black nose, with a long snout that is covered in whisker like hairs. They have small, bright black/brown eyes, and ears. Their necks are very short. They have 4 short legs, feet with five toes and a short tail at the rear. The Hedgehogs upper part of the body is covered in spines, which are cream/yellow tipped and brown at the base.

Distibution:

Hedgehogs are in decline, but are a widespread mammal that range through out Europe, which includes Britain, Romania and Scandinavia. They have also been introduced to New Zealand.

Habitat:

Hedgehogs can be commonly found in forests, hedgerows, scrub land, parks and playing fields, and in gardens. It has been found that fewer numbers are occupy marshlands, damp woodlands, conifer plantations and dense pine forests.

Natural Diet:

Hedgehogs eat a variety of invertebrates such as Beetles, Earth Worms, Slugs and Snails. They also have been known to feed on the eggs or chicks of ground nesting birds. For more information you can see the 'Natural Diet' page. 

When Active:

Hedgehogs are nocturnal. They sleep during the Day and forage for prey during the night. It has been found that Hedgehogs are mainly active after heavy rainfall.

Territory:

Hedgehogs are not territorial, they are solitary. Males will cover a larger area at night than females. Hedgehogs which have been seen at 'feeding stations' have been observed to sometimes fight, but this is often avoided. 

Behaviour:

Hedgehogs will sometimes cover their spines in frothy saliva, which has been considered very strange. This is called 'self anointing'. This can sometimes happen when the Hedgehog experiences a strange taste, although the full reason is not yet known.

Reproduction:

The breeding season runs from around May to late September, although it has been found that if the weather is warm, Hedgehogs may breed even later into the year. Most Hedgehog births are around June or July, and courtship showing a peak in August or September. Courtship is usually very aggressive, which consists of loud grunting, circling and even head butting. Females produce 1 to 2 litters of Hoglets a year, and the typical number of Hoglets in a litter is 4 or 5, after a 35 Day gestation. Hoglets are suckled on their mothers milk, and are weaned by the time they are 6 - 8 weeks old. They will leave the nest to forage with their mother at around 4 or 5 weeks old. Hedgehog become independent by the time they are 4 months old.

Nests:

Hedgehogs will often construct loose nests in the summer, and in Winter a stronger nest called a 'hibernacula'. Hedgehogs will also nest in Hedgehog Boxes, which can be put down in gardens. Hedgehogs have also been known to sleep in long grass when the weather is warm.

Hibernation:

Hedgehogs will go to sleep for a long period of time during the Winter. This is because of the Hedgehogs poor insulation, meaning that they are more exposed to the cold, as well as the fact that food is scarce. The Hibernation nest is called a Hibernacula, and is typically situated under Hedgerows. Hibernation may last until March or April. The body temperature will fall dramatically as well as the heart beat, from around 190 to 20 beats per minute. Most Hedgehog deaths occur during the cold months. This is mostly due to lack of fat reserves.

The Hedgehog Senses:

Eyes: Sense of sight:

Hedgehogs are nocturnal and inhabit areas of dence undergrowth where their vision is likely to be obscured, making their eyesight unimportant. The Hedgehogs Retina, which is made up of photoreceptors, consists of Rods, which are for monochromatic vision only. Hedgehogs have very few Cones if none, which are for colour vision. This means that the Hedgehog will only be able to see in dark colours. However, it has been found that in good light conditions, Hedgehogs may have some colour vision, though very limited indeed. Hedgehgs have been known to discriminate between certain colours, again only in good light conditions. That aside, they can also tell apart certain shapes, as well as landmarks and moving objects as silhouetted shapes in the Moon light. Because of the Hedgehogs vision, a partially blind Hedgehog will still have a good chance of surviving.  

Ears: Sense of hearing:

Hearing is very important to a Hedgehog, one of its main strengths. Hedgehogs have a high frequency auditory system, with which they can easily pinpoint prey such as invertebrates when foraging. Hedgehogs probably hear in ultrasonic (20kHz and above). As I and many other people have found out, Hedgehogs will often flinch or curl up when they hear clicking or chirping, due to the ultra-sonic components of the sounds. This can happen when light switches are clicked, or tongues, even when keys are shook.

Nose: Sense of smell:

There has not been much research done into the Hedgehog's sense of smell, however it has been said that the Hedgehog's nose plays a very important part while the Hedgehog is foraging for food. This can also be used to recognise other Hedgehogs, to detect danger, and to also follow any scent trails. It is also thought that its highly developed sense of smell is important for reproduction and sociality.

Sense of Touch:

Most of the Hedgehog's sense of touch is on the face, they have long sensory tactile hairs on their snout, as well as guard hairs that fringe its spines.

The Spines:

The Hedgehogs upper part of the body is covered in spines, which are cream/yellow tipped and brown at the base. The spines are modified hairs, which are actually hollow inside, growing up to 2 ½ cm (1 in.) It has been found that a single spine can support the whole weight of a Hedgehog. By the time a Hedgehog is weaned, they may have as many as 3,500 spines, and an adult Hedgehog having up to 7,000. Each spine can move independently, because they are all attached to their own muscle, which is then attached to a large muscle which lines the Hedgehog's back. When the Hedgehog wants to roll up into a ball, it contracs the panniculus and the muscularis orbicularis. When in danger, the Hedgehog will erect its spines, and draw them down to cover its tail, feet and face. The Hedgehog will then roll up into a tight ball if still in danger. 

Hedgehogs do loose their spines, but not all at once. They moult them individually through a long period of time. Some Hedgehogs will have lost their spines due to injuries and illness- if this is the case, most of the time the spines will grow back, though this may take a while; and sometimes if the Hedgehog is very old, the spines may never grow back, in these cases, if there are many spines lost, the Hedgehog may die.

Page Last Updated: 9th July 2009