For most of the hedgehogs in our gardens preparing to hibernate is the focus of their activity over the autumn months. Hibernation is a crucial but dangerous part of the hedgehog year. And what happens in autumn is critical in determining whether our hogs make it through to next spring. So this week we’re looking at how to help hedgehogs in autumn.
What Are Hedgehogs Doing in Autumn?
To understand how to help hedgehogs during the autumn months we first need to take a look at what they might be doing. And there’s a lot going on!
Foraging for food and eating is always a big part of the hedgehog’s routine, but in autumn eating becomes more important than ever.
An adult hedgehog needs around 130 calories per day to maintain her weight. That equates to bout 75 grams of food. This is well over 10% of body weight for an average hedgehog.
Invertebrates are a key part of the diet and studies have shown that an adult hog can eat over 100 in one night. Hedgehogs love bugs!
But this is just the amount of eating needed for a hog to maintain his weight. In autumn hedgehogs are aiming to gain weight to see them through hibernation.
Although hibernation is a mechanism for conserving energy during the winter months, hedgehogs still need to have good energy reserves, in the form of fat, stored up in order to hibernate successfully.
There is much debate about exactly how much a hedgehog should weigh before going into hibernation, but at least 500 grams is an absolute minimum.
For most hedgehogs, this means putting a real focus on eating to put on as much weight as possible before going into hibernation.
Studies have shown that hedgehogs, especially juveniles, can extract more calories from food in autumn than they can at other times of the year.
This certainly helps, but there is still a need for hedgehogs to find more food each night during autumn And as the weather grows colder and invertebrates and other favourite foods, start to disappear this can become more and more difficult.
Hedgehogs use daytime nests to nap in throughout the summer. But the nests that they hibernate in – hibernacula – are are much more elaborate affair.
Hibernation nests are built with care and attention to detail. They have to be, they need to be warm and dry enough to keep a hibernating hog safe all winter.
Hibernacula are built with layer upon layer of leaves, pressed flat by the hog circling inside them. The finished walls are almost like lamination, with the closely packed layers of leaves forming walls at least 4 inches thick. Overall the nest will be 18 inches to 3 feet across, circular in shape with a short, narrow entrance tunnel.
Hedgehogs look for quiet, dry nesting sites in tree roots, old rabbit holes, under decking or even in your garden shed!
Although hedgehogs are known for breeding and having young in early summer up to 80% of females will also have a second litter much later in the year.
Late litters can be born any time from August to November.
Knowing what we do about how much a hedgehog needs to weigh in order to hibernate successfully it’s easy to see that late litters present a challenge for both mother and babies. Hoglets weigh just a few grams at birth and must get up to over a pound in weight in just a few short weeks if they are to survive the winter.
And mothers, who could be busy feeding themselves up for hibernation, are spending time and energy rearing young instead.
It’s tempting to look at late litters and see them as some sort of an evolutionary design fault. But when we look in a little more detail we can see that there may be good reasons why hedgehogs continue to have late litters.
When hedgehogs hibernate has always been very variable depending on the individual, the location and weather.
Males, who don’t get involved in late litters after the act of mating, can focus on fattening up during the late summer and typically hibernate much earlier than females. They may even be out for the count by late September.
Hedgehogs in the north typically go into hibernation several weeks before those in the south. And a mild autumn, where food remains abundant for longer, will see hibernation delayed.
Even so, late October and November in the UK traditionally saw most hedgehogs tucked up for the winter.
Global warming has changed all that and as any rescuer will tell you, hedgehogs are hibernating later and later each year, with some seeming to stay active all winter.
Is this a problem? Maybe, maybe not. Hedgehogs don’t biologically need to hibernate like we need to sleep. If there is enough food around they can do just fine without hibernation, even in pretty chilly circumstances.
In New Zealand’s North Island, hedgehogs imported from the UK over 100 years ago and living in the wild don’t hibernate. They live significantly longer than UK hogs, meaning each individual gets the opportunity to produce more offspring.
This is just part of the reason why, hedgehogs endangered in the UK, are now considered a pest in New Zealand where they are not a native species.
So maybe we’ll see some hedgehogs going into hibernation during the autumn months, but it’s increasingly likely to be December or even January before they bed down for the winter. But maybe having a shorter hibernation, or not hibernating at all isn’t such bad news for the UK’s hedgehog population.
How To Help Hedgehogs in Autumn
From taking a look at what hedgehogs are doing in autumn we can start to see what we might be able to do to help.
Stock Up On Hedgehog Food
It’s rare to find an overweight hedgehog, so almost all of our hogs will be eating more to bulk up for hibernation. And as the foods that make up their natural diet become more scarce, the need for us to provide extra food increases.
If the hedgehog food you leave out each night is disappearing now is the time to add a little more. Keep upping the quantity until you find you are getting some left in the mornings, then start to decrease.
I prefer dry hedgehog food for the summer months, but as the days and nights get cooler wet or dry is fine. Or of course, you could go for meaty dog food or cat food.
Don’t forget to leave out fresh water, in a heavy shallow bowl, too.
For our full guide on what to feed hedgehogs and what foods are best avoided, check out this article.
Provide a Hedgehog House for Hibernation
Building a good hibernation nest takes practice and it’s easy to spot the efforts of young hogs going into their first winter. These nests won’t win any prizes and often won’t do a fantastic job of keeping a young hog safe and dry for the winter.
This is why young hogs often take advantage of hedgehog houses – they provide a secure framework for building a winter nest.
So if you don’t have a hedgehog house, now is a good time to buy or build one. And if you already have one, maybe another wouldn’t hurt? Hedgehog houses provide hedgehogs with a safe place to hibernate or raise a family. They’re a good thing to have around the garden.
Add Some Nesting Materials
Leaves are a key nest building material for hedgehogs. This means that if you have trees in your garden you now have the perfect excuse not to do too much leaf-raking this autumn!
If your garden doesn’t have trees help hedgehogs by taking a sack to a local park or woods and gathering up fallen leaves for nesting. It’s a fun October half term activity.
You could leave a pile of leaves by your hedgehog house as a gentle hint. You could put some inside but don’t be offended if your hog drags them all out again. Gathering nesting materials and building the nest from scratch is an important part of the hibernation process.
Don’t Cut Back
Our gardens can look especially bedraggled and messy as autumn advances and more and more plants go over.
It’s traditional to cut back and clear up at this time of year. But for wildlife including hedgehogs, this is a bad idea.
Even dead and dying plants offer a home and food for invertebrates, which in turn are the main food for our hedgehogs.
So for the sake of the wildlife, try to cut back as little as possible until new growth starts to appear in the garden in spring. If you can, leave things to go a bit wild.
Weigh Hedgehogs In Your Garden
We’ve discussed how important it is for hedgehogs to be carrying a good amount of fat when they go into hibernation. So if you have hedgehogs in your garden autumn is the time to pop them on the scales and check how they are doing, if you get a chance.
Using a pair of gardening gloves or a towel, it’s easy to scoop up a hedgehog and pop him or her on the scales. It won’t worry the hog, and as long as you are suitably protected from prickles, it won’t hurt you.
You can read our guide on what is a healthy weight for a hedgehog here. But as a rough rule of thumb, a hedgehog weighing less than 500gms will not survive hibernation.
Hedgehogs tend to start to hibernate when nighttime temperatures regularly fall below 5c.
So if you have underweight hedgehogs in your garden when temperatures start to drop contact your local rescue centre or the British Hedgehog Preservation Society who will advise you on the best way to help.
Watch Out For Autumn Juveniles and Injured Hedgehogs
When hedgehogs hibernate they need to be at a good weight and in good physical condition to stand the best chance of making it through to the spring.
An injured hedgehog or hog that is sick will very likely not make it through hibernation. In the interests of hedgehog conservation, these hogs should be taken to a vet or local rescue centre.
Likewise with autumn juveniles. Any baby hedgehogs born in September or later will really struggle to put on the weight they need for the winter hibernation. Read our guide to helping autumn juveniles here.
Take Care When Gardening
Leaf piles, log piles, the compost heap, bonfires, garden sheds and long grass are all favourite hedgehog hangouts. Though so many of us are keen to help hedgehogs and attract hedgehogs to our gardens, still many hedgehogs perish every year in gardening related accidents.
If’s easily done, a balled-up hedgehog is very well camouflaged in the colours of an autumn garden. So please, to protect hedgehogs and other wildlife, take extra care when gardening at this time of year.
Thanks for Reading
Hedgehog numbers in the UK are in steep decline and our prickly friends need all the help they can get. At any time of year, our gardens are playing a more and more important part in hedgehog conservation, by providing that kind of hedgehog friendly habitat that’s becoming increasingly scarce in the countryside.
But in autumn the help we give by providing food and keeping a close eye on the health and size of visiting hedgehogs is absolutely crucial in helping more individuals make it through the winter and on to the next breeding season. So let’s keep up the good work!
Thanks for reading, we hope you’ve enjoyed this post and found it useful. If you have questions or suggestions we would love to hear them. Leave us a comment below.