Hedgehog Day

What the day is

Hedgehog Day is observed on February 2. The hedgehog held the job first: the German tradition of watching a hibernating animal's shadow at Candlemas used one, and settlers in Pennsylvania substituted the groundhog because North America has no hedgehogs.

Origin and background

The animal itself is more unusual than its garden reputation suggests. Hedgehogs are insectivores rather than rodents, and their closest relatives are moles and shrews rather than anything that gnaws. The spines are modified hairs, stiffened with keratin, and a hedgehog has several thousand. Unlike a porcupine's quills they are not barbed and do not detach; defense works by a dedicated muscle running around the body that draws the skin closed like a purse string, pulling the animal into a sphere with nothing exposed.

They do genuinely hibernate, which is why they were the original subject of the shadow tradition. British hedgehogs enter hibernation through late autumn and emerge around March, and a hedgehog active in midwinter is usually a hedgehog in trouble rather than an early riser.

The conservation picture is poor. Hedgehog numbers in Britain have fallen sharply over recent decades, particularly in the countryside, driven by loss of hedgerows and field margins, intensive farming, road deaths and the fragmentation of gardens by solid fencing. A hedgehog ranges over a mile or more in a night, and a garden it cannot leave is not habitat.

The best-known remedy is also the simplest: a gap of about thirteen centimeters square at the base of a fence lets hedgehogs pass between gardens, and coordinated across a street it reconnects a whole neighborhood.

How to take part

• Cut a hedgehog-sized gap in your fence and ask neighbors to do the same.
• Put out water rather than milk, which hedgehogs cannot digest.
• Check long grass before strimming, which causes appalling injuries.
• Leave a corner of the garden untidy, which is where they nest and feed.
• Call a rescue if you see one out in daylight in winter. That is a warning sign.