Hedgehog

Overview

Order: Eulipotyphla

Family: Erinaceidae

Species: 17 species exist

IUCN Red List Status: UK: Vulnerable; Global: Least Concern

Population trend: falling in UK.

Distribution: widespread, from Britain and rest of Europe, except the far north, across to Russia. Absent from most Scottish islands. Introduced to New Zealand.

Habitat: mainly woodland habitats, hedgerows, fields, parks, town and country gardens.

Description: distinctive spiny coat; long, coarse hair on face and underparts.

Size: length:- 20 - 30 cm.

Weight:- average 700g.

Life-span: can live up to 6 years.

Food: slugs, snails, caterpillars, beetles, earthworms, birds' eggs; sometimes frogs, snakes and carrion.

The hedgehog is the most easily recognised of British mammals yet they are steadily disappearing from the wild. As its name suggests it spends the day sleeping in hedgerows or under shrubs. Old names for it have been 'urchin' and 'hedgepig' and it has been the subject of some strange folk tales. One was that hedgehogs picked up fruit on their spines and another that they sucked milk from cows - both unlikely!

Hedgehog Habits

Daily Life: a hedgehog is normally a solitary, nocturnal animal. During spring and summer days it sleeps in a temporary nest and wakes up at dusk to venture out and hunt for food. It is an insectivore and eats all sorts of invertebrates, is partial to birds' eggs and raids mouse nests for newborn young. In autumn, soft fruit is eaten.

A hedgehog may roam over 2 - 4 km a night in search of food. As it searches, it will climb short stone walls, fences and even swim across water.

Hedgehogs are noisy animals, snuffling loudly as they shuffle through the undergrowth. They have poor eyesight but an acute sense of smell, touch and hearing.

If threatened with danger, a hedgehog will raise its spines and roll up into a tight ball. This will deter most animals, though a determined fox is capable of opening one up! The spines are really modified hairs about 25mm long. An adult hedgehog has about 3,000 - 5,000 spines. Each one lasts about a year before it drops out and a new one is grown.

A hedgehog has the strange habit of 'self anointing'; when it comes across a strong smell or taste it twists its head round and, using the tongue, covers its spines and fur in a frothy saliva - looking as thought it is covered in soap bubbles! This behaviour is quite normal but no-one knows its purpose.

Winter: the hedgehog's food is in short supply during the winter, so it spends the coldest months hibernating in a specially prepared nest; this is usually at ground level in a hedgerow, a compost heap, under a thick layer of leaves or under logs. Before curling into a tight ball in this hibernaculum, the hedgehog spends the autumn eating as much food as possible to store it as fat which is used up during sleep. If sufficient fat has not been stored during the autumn, the hedgehog may die during a long, hard winter. Hibernation usually lasts from November until March. During this time the body temperature drops to that of its surroundings and breathing almost stops.

 

Threats to the Hedgehog

Hedgehogs are in trouble in the UK as reports come in that fewer hedgehogs are seen every year. Recent surveys show that hedgehog numbers
declined by approximately a third between 2002 and
2012 and sightings fell by 4 percent just in 2014. Rough estimates put the hedgehog population in England, Wales and Scotland at about one million, compared with 30 million in the 1950s.

In the past, gamekeepers killed hedgehogs because they ate the eggs of gamebirds. Today it is regarded as beneficial and is often called the gardener's friend as it eats large numbers of slugs, snails and other garden pests.

Although the hedgehog is in decline and receives some protection from the Wildlife and Countryside Act of 1981, it is not officially a threatened species. Thousands of hedgehogs die every year for a variety of reasons, most of them caused by humans. Here are some hazards faced by hedgehogs:

• Road traffic; this is probably the biggest danger during the spring and summer. Since hedgehogs roll up when threatened with danger they are easily squashed by cars when trying to cross the road. As the numbers of cars increase, more and more hedgehogs are killed.
• Habitat loss; The growth in intensive farming since the 1940s has removed many of the hedges, woods and small fields in which hedgehogs thrive.  The trend for tidy gardens and lots of decking and paving have also reduced the ‘messy’ habitats of mixed vegetation and fallen leaves that hedgehogs love.
• Chemicals; the use of garden chemicals such as insecticides and slug pellets is a threat. They reduce the natural food available. Also, tiny quantities of chemicals are present in slugs, beetles etc. and as hedgehogs may eat hundreds of these every month they can soon accumulate enough poison to affect their health.
• Drowning; if a hedgehog falls into a swimming pool or steep-sided pond, it often drowns because it cannot climb up the smooth sides. A strip of wire netting fixed to the side, or a pile of stones at the edge will let the hedgehog escape.
• Cattle grids; hedgehogs often fall through these and cannot climb out so they starve to death. Ramps or tunnels are now usually built inside the pit to let the hedgehog escape.
• Hibernation; more than half of all hedgehogs die during hibernation due to cold, fire, flood or someone wrecking their nest.
• Garden machinery; always worth check long grass for hedgehogs before using a strimmer or a mower.  Hedgehogs can be seriously injured or killed accidentally by gardeners using these kinds of tools.

Helping Hedgehogs

Our garden can be an ideal habitat for hedgehogs, provided we do not use chemicals for killing pests, such as slug pellets, and do not tidy up too much.

To encourage hedgehogs into the garden, and help them fatten up for the winter, saucers of tinned cat or dog food may be put down. Once used to this treat, the hedgehog will regularly return for its supper.

We can provide the hedgehog with a good place to hibernate by placing a bundle of straw, hay or leaves under a dry shed, thick hedge or log pile. A special box can be made and covered with polythene and soil. We can also help hedgehogs by making sure we have access points to our gardens - if your garden is walled you might want to consider removing a brick so that hedgehogs can pass through and continue on their search for food and a mate - the same goes for fences and can be remedied by digging a tunnel udnerneath the wall or fence or making a small hole.

Hedgehogs often hibernate under compost heaps and piles of garden litter destined to be bonfires. Be careful when breaking up the compost heap or lighting the bonfire - check there is not a hedgehog sleeping there!

If you would like to find out more about helping hedgehogs take a look at Hedgehog Street and the British Hedgehog Preservation Society.

If you see a hedgehog, you can report the siting at:
https://bighedgehogmap.org

https://ptes.org/log-your-hog/

http://www.wildlifeinformation.co.uk/hedgehog_sightings.php

Credits

Image: Hedgehog by Alexander Olm

Infomation sourced from:

Lean, Geoffrey (2015), The Telegraph, Our humble hedgehog is disappearing fast [online], Available from: http://www.telegraph.co.uk/news/earth/wildlife/11449901/Our-humble-hedgehog-is-disappearing-fast.html [accessed 28/06/2015].

Breeding

Hedgehogs are ready to breed in April. If you hear loud snuffling and grunting noises at night in the garden, it may be hedgehogs mating. The male (boar) circles round the female (sow), sometimes for hours, trying to persuade her to mate. After mating, the male leaves, taking no part in rearing the young.

The female makes a special 'maternity' nest of leaves and grass, and after a gestation period (the time between mating and birth) of about 32 days, three to five babies are born. At first, the young are blind and pink but soon sprout soft white spines. Their eyes open at about 14 days and they grow more and more brown spines. Their mother suckles them until they can hunt for themselves. She takes them on their first foraging trip after 4 weeks and 10 days later they all go their separate ways. A second litter may be produced in late summer, but seldom survives the winter because there isn't enough time to make a good store of fat.