Hedgehogs in Decline

The presence of a hedgehog in your garden is a good sign that your biodiversity is high. Sensible gardeners welcome these nocturnal insectivores because they also love to eat slugs. But this once common animal is now threatened in France. What is perhaps most alarming is that it is in rural areas that they are declining most.

A hedgehog being filmed for a nature programme at Chenonceau.

Hedgehogs have a naturally high mortality rate. One in five babies doesn't survive to leave the nest. Once out in the big wide world they can succumb to parasites, predators such as weasels and foxes, or not make it through a hard winter. But increasingly the cause of death is not natural. A million are being hit by a cars annually, and a similar number poisoned by pesticides. Some of them drown in swimming pools. Their habitat is being altered and degraded so they have to travel further and further to find food.

A hedgehog in our driveway.

In urban areas the population density of hedgehogs is between 15 and 37 individuals per square kilometre. In rural areas the numbers drop to between 1 and 4 hedgehogs per square kilometre. In the last 20 years the population has declined by two thirds. In the past you could expect a hedgehog to live about 10 years, but now the lifespan is about two years, because they are exposed to more risks.

Ecologists consider the hedgehog both an umbrella and an indicator species. What is happening to them is likely to be happening to other small wild creatures. The National Natural History Museum points out that if we restore habitat such as hedges, natural vegetation and enclosed bocage field systems for hedgehogs then other groups such as insects, snails and spiders benefit.

If you want to help your local hedgehogs the two most important things you can do is not use pesticides, so there is plenty in your garden for them to eat, and provide a 'wild' area of long vegetation and undergrowth that they can safely make a nest in. They like leaves, piles of light wood and twigs, moss and compost to hide and hibernate in. If it is practical (ie if your pets are not allowed out at night and you are not going to attract rats) you can leave out cat or dog food for resident hedgehogs in the autumn. This will help them reach a suitable weight for hibernation and increase their chances of surviving winter.