Autumn and winter are critical times for our hedgehogs. When preparing for survival over the bleaker months, it pays to be large like the biggest hedgehog we’ve seen in our garden, ‘Hodge’. Smaller hedgehogs may need our help as the cold, clammy fingers of winter approach. Some advice follows on when to intervene, and how.

Our garden hedgehogs

I am fortunate that I can keep an eye on our prickly garden visitors using a wildlife camera that takes photos and short videos. If you don’t have the luxury of a wildlife camera, you may need to do a bit of night-time spying to see who’s there. To find out if you have hedgehogs, look for hedgehog poo or make a footprint tracking tunnel (just like Cornwall Wildlife Trust's Head of Conservation Cheryl did in the video below).

With my static trail camera, I can check how often hedgehogs visit, how large they look, how well they are moving, and whether they are eating and drinking from bowls I leave in a lean-to hedgehog shelter by the hedge. As the camera is set quite low on our gate, I can see the pads of their little paws, the skirt of fur beneath the prickles, and sometimes the soft underbelly as they run along the path or stop to have a scratch or shake the rain off. Mostly, they are seen foraging alone, snuffling around for edible morsels at the edges of the garden path.

Telling these animals apart using camera images is not particularly easy. A rounded hedgehog with short legs looks like a different creature when it stands tall and seems to pick up its fur skirt to run. This autumn, our regular visitors appear to consist of (or include) one large and substantial hedgehog (the aforementioned Hodge), a lively, scruffy male that runs briskly on long, thin legs (unnamed; we could call him Scruffy), and a smaller, tidier looking female (Hedgey). In late summer, however, there seemed to be up to six different hogs, including a baby that I met in person one evening.

Feeding hedgehogs

Hedgehogs may have a second litter of hoglets in late summer. These become extra-vulnerable as the cold sets in. It is not unusual to find ones that are old enough to be independent from their parents, yet too small to survive the winter without help. According to research, the very lightest weight for likely survival over winter is 450g (1lb) but this will depend upon other factors such as the weather, and the abundance of food in our gardens. A safer weight is 600g (about 1lb 5oz), although survival still cannot be guaranteed.

It’s actually quite easy to pick up a hedgehog wearing gardening gloves (they don’t have to be thick ones) and put it on some kitchen scales. However, this should only be done when necessary, to avoid disturbing and alarming them. Hedgehogs usually ‘freeze’ if approached, hoping that something inanimate and spiky will be unappetising to potential predators. This keeping still reflex is one reason why so many become road casualties. However, if you leave a hedgehog alone while going in to fetch the scales, it will probably run and hide while your back is turned.

Being captured and then shut in a cage or hutch can be very stressful for hedgehogs, so if a youngster is near the survival weight threshold and seems active and healthy, it’s best to feed it rather than take it indoors, unless a cold winter has already set in. It’s surprising how quickly healthy young hedgehogs can gain weight. Remember, hedgehogs are distant relatives of the carnivorous shrews, and their diet is mostly meat-based.

Our local pet shop supplies a variety of hedgehog foods. This is useful, as hedgehogs benefit from a varied diet (I buy dry, semi-moist and tinned proprietary hedgehog food, plus rather expensive dried ‘calci-worms’, which look like normal beetle larvae mealworms but are actually the calcium-rich larvae of the Black Soldier Fly [Hermetia illucens]). Hedgehogs love mealworms, but the sort that are widely available can cause metabolic bone disease in hedgehogs. The problem occurs because calcium-poor mealworms can be rather addictive and are eaten in large amounts, to the exclusion of other foods.

As hedgehog food can be expensive, I mix it with meaty wet or dry cat food. If a garden is wildlife-friendly, there should still be some natural foods around at this time of year (mid-November as I write), such as slugs (see the 'A thank you gesture from your hedgehogs' below), or even carrion or fruit. We need to get the right balance between allowing natural foraging behaviour and helping a species that is threatened with extinction.

It is crucial to leave a dish of water alongside hedgehog food, but never leave milk, which causes severe digestive upset. Visit the 'What to feed hedgehogs and badgers' and 'How to build a hedgehog home' pages on the Cornwall Wildlife Trust website for more information on what to feed them and how to build a feeding station that can't be accessed by cats and dogs. 

When to rescue a hedgehog and who to turn to

If a hedgehog seems wobbly or unwell, is lying around exhausted or trying to absorb heat from the sun, or is clearly lighter than 450g soon before winter, it ought to be rescued. Hedgehogs have become too scarce to sacrifice. If a small hedgehog is in a tight ball and not hidden away, it probably has hypothermia, as hibernating hedgehogs would be safely inside a leafy nest. Fortunately, there are probably hedgehog experts not far from where you live, as well as hedgehog rescue centres like Prickles and Paws in Cubert, Newquay. The British Hedgehog Preservation Society (01584 890 801) can help if you have found or are concerned about a hedgehog and can put you in touch with your local hedgehog carers.

Wildlife rescue organisations and friendly vets can also help hedgehogs in distress. While your hedgehog is waiting for expert help, the Hedgehog Street website explains how to keep the patient warm in a box with a wrapped hot water bottle.

Other vital hedgehog needs

Whatever the time of year, it is essential to give hedgehogs access in and out of gardens, and to keep gardens hedgehog friendly. This means:

• Grow hedges and if possible do away with that fashionable solid wood fencing we see so much of, or at least ensure there are gaps beneath fences, or hedgehog-sized holes. Ask your neighbours to do the same, if you can.

• Avoid artificial lawns; this goes without saying. A hedgehog cannot forage on plastic grass.

• Avoid slug pellets and other poisons, and do not flea-spray a hedgehog with dog or cat insecticide products.

• Remove hazards such as plastic bags and other refuse.

• Keep an eye on dogs, which might harass or attack a hedgehog.

• Have a pond, to encourage all sorts of wildlife, but do ensure easy access in and out.

• Keep areas of the garden wild and ‘untidy’, and be extremely careful when using strimmers, garden forks and other sharp garden tools.

• Provide safe havens for nesting, such as piles of branches, quiet corners and cosy hedgehog houses. 

A thank you gesture from your hedgehogs

According to BBC science reporters, ‘sleepless slugs’ remain active in temperatures of about 5°C. This means that although many are harmless or even prey on smaller slugs, various others eat and destroy delicate seedlings, overwintering lettuces and other delicate and tasty vegetables. So, from a purely selfish point of view, as climate change gathers pace, we gardeners need our hedgehogs more than ever.

Support your garden hedgehogs through our mild winters, supplement their natural food to help them survive, and they will reward you by contributing to a healthy predator/prey balance that will benefit your garden. And if you get a wildlife camera, they’ll provide plenty of entertainment value too.

How you can take action for hedgehogs this winter

• Donate to Cornwall Wildlife Trust’s hedgehog appeal to support Operation Hedgehog and help reverse the serious decline of this special, native species.
• Watch our 'Wildlife Matters LIVE - Operation Hedgehog Update and Q&A' event with speakers from Cornwall Wildlife Trust, Cornwall Mammal Group and Prickles and Paws. 
• Share your hedgehog records with the Environmental Records Centre for Cornwall and the Isles of Scilly (ERCCIS).