Surveys show that our gardens are the last refuge for these prickly slug-eaters. Adrian Thomas looks at what we can do to make them more welcome
My garden is full of shrubs and flower borders, log piles and secret places, yet in the four years I've been here I have yet to see a single hedgehog. I've not heard the tell-tale snuffling when I'm out at night looking for bats; there ahave been no sightings on my automatic trip-wire trail camera. This is a sad reflection of the picture across much of Britain; for every 100 hedgehogs that were here in the 1950s, there are just three today. The overall population is now probably less than a million, although exact numbers are difficult to pin down for this nocturnal mammal.
Sadly, the numbers are still on a downward trajectory. This means that some populations are becoming isolated from each other; for example, the 30-40 individuals still found in Regent’s Park are now thought to be the only ones in that part of London.
The declines are thought to be due to a range of factors, including the changes in our farmed landscape as herbicides and pesticides remove much of the creepy-crawly food that hedgehogs rely on. However, we can’t ignore the effect of the motor car. In 2017, British motorists travelled a record 327 billion miles on our roads. That’s one major risk for any hedgehog trying to cross to the other side, and it’s estimated that about 150,000 are killed each year in this way.
But there is a ray of hope. The State of Britain’s Hedgehogs 2018 report by the British Hedgehog Preservation Society (BHPS) and the People’s Trust for Endangered Species (PTES) showed that maybe, just maybe, the decline is levelling off in urban areas. While we don’t know why that may be, we do know that a hedgehog-friendly garden can be a brilliant home for them. This is one species for which we can make a very real difference.
One of the main ways people can help is by providing a hedgehog home. Every garden centre and wildlife charity stocks them, and they come in a wide range of shapes and sizes, some looking like glorified wooden boxes, others like upturned wicker baskets. But, crucially, do they work?
Last year more than 5,000 people took part in a survey organised by PTES to find out how effective artificial boxes are for hedgehogs. The first results are now out (although there is still much number crunching to be done). The headline conclusions so far are that, across the country, there are many hedgehogs happily using artificial nestboxes to hibernate, to shelter in by day during summer, and even in some cases to raise their young.
However, what may seem an odd result is that home-made boxes turned out to be better than shop-bought versions, on the whole. I strongly suspect this is because many shop-bought ones just aren’t large or robust enough. In contrast, the DIY designs you find online all tend to be the bespoke ‘des res’ version, with enough space inside for a hedgehog to fill it with leaves and raise a brood of four or five young.
The survey also found that it often takes time for a hedgehog to move in to a new box. You can imagine that, to these creatures that have a much finer sense of smell than us, a fresh box smells rather different to the garden around it, and hence is viewed with some suspicion. So, if the hedgehog home you laboured so lovingly over isn’t used in the first couple of years, but you know you have hedgehogs in the area, don’t despair. As the box weathers and ages and blends into the garden, there’s every chance a hog will move in.
Of course, a box is only one element of a hedgehog’s needs. To survive in a garden, they will need a plentiful supply of worms, slugs, beetles and other natural food. Plus they much prefer to nosey about in places where there’s plenty of cover, such as along hedgerows and under shrubberies.
The final piece of the jigsaw is that hedgehogs need ready access in and out of your garden. They need to wander a mile or more in the course of a night in search of food, and of course males and females need to find each other in spring, and that means having the freedom to roam. Boxy modern gardens with impassable high fences are no use to a hedgehog. Simple hedgehog highways, cut in the base of a fence panel about 12cm square (or a circle the size of a CD) are exactly what they need to slip from one garden to the next.
Do all this and you still have a great chance that your garden will be the ideal home they’ve been looking for. With enough gardeners playing their part, gardens can become the premier hedgehog haven in Britain.
Build a hedgehog home
With just basic DIY skills and some sheets of plywood, it’s easy to knock up a simple hedgehog home. My recommended design is suitable as a nursery nest and as a hibernaculum. It includes an entrance tunnel that leads into the main chamber, giving them extra security from disturbance and predators.
You will need: Two sheets of FSC exterior plywood, 60cm wide x 2m long, 1.5cm thick • Saw, hammer, screws and handsaw
1. Mark out the pieces of wood according to the diagram (left), and cut to size.
2. Assemble the pieces into a main box (minus its roof) and entrance chamber, using screws (or nails).
3. Screw the entrance chamber to the front of the main box. The idea is that a hedgehog accesses the box via the entrance chamber and then turns into the secluded inner main box.
4. Fasten the main roof down, ideally with screws so you can inspect and clear out the box in early spring.
Remember to clean out the hedgohog home once a year (late March-early April), after the hedgehog has finished hibernating, to avoid a build up of pests.