What is a Hedgehog and what does it look like?
Generally speaking, the hegdehog is a small
spiney mammal (indeed it is Britain's only spiney mammal) which
belongs to the group Erinaceus europaeus. It has spines
covering most of the upper part of the body, walks on four legs,
is a nocturnal feeder and eats insects. It is this last fact
which makes this mammal one of the most welcome wild animals in
Britain today. It's ability to eat it's bodyweight in insects in
one night (many of the insects that are considered harmfull to
plants) means that a hedgehog can help the gardener to keep
pests down to a managable level completely naturally.
What are the spines used for?
The spines on the back of a hedgehog are
actually modified hairs, there can be five thousand spines on an
average hegdehog. Each spine growing to about an inch long and
lasting 12 months before falling out and being replaced by a new
spine. Muscles under the skin allow the spines to be erected for
protection, since the lower part of the hedgehog is covered in
soft fur and is thus vunerable to attack if it can be turned
To get around this problem, the hedgehog's
skeleton is shaped with a long spine, which allows it to curl up
into a ball if threatened. More muscles around the edge of the
spines allow the spines to be drawn together, surrounding the
head and legs.
Thus it can turn itself into a ball of spines which should prove
a positive defence against unwanted interest from a predator.
The picture on the right shows a curled up hedgehog turned over
on it's back to show the completeness of it's defence.
Are they all brown?
The colours of hedgehogs are generally as the
picture on the right, a brown colour. However, hedgehog colours
can also range from white (such as the blond hedgehogs which
have thrived in Alderney, in the channel islands) through to the
very rare black variety. Albino and sometimes spineless
varieties are found but invairably these are already dead due to
their colours proving no camoflage during the night from their
What's under the skin?
The skeleton of a hedgehog is very basic and
shows the length of time that the hedgehog has been with us. It
is estimated that the hedgehog has been evolving for over ten
million years, making it one of the oldest species of mammal. It
has 36 teeth which are suited to it's diet. However, these teeth
are incapable of delivering a serious bite to humans. Their long
legs and short tail are mostly hidden underneath their spines
and the hair along the sides of the body. The feet have five
toes which have strong claws growing from them.
How big do they get?
Size can vary in a hedgehog depending on age,
sex and time of year. Below are some typical weights:
|Time of year and Life stage
||120 - 150g
|1 year old after winter
||400 - 500g
|Adults after winter
||450 - 600g
||at least 750g
|Adult male before winter
||650 - 1500g
|Adult female before winter
||600 - 1000g
As you can see, the time of year is important to
the size of the hedgehog. This is because the hedgehog
hibernates (sleeps) through the wintertime and must rely on
stored fats in the body to see it through to the spring. Indeed,
a hedgehog must weigh at least 450g to be able to survive the
Why do hedgehogs hibernate?
Hedgehogs hibernate to conserve their energy
since the cold months of the year mean that food becomes scarce.
The hedgehog simply tries to bypass that time of year
completely. It does mean, however, that they need to have stored
up enough body fats to take then through the winter.