Does Rescuing Hedgehogs Work? Can Released Hogs Survive and Thrive in the Wild?

Thousands of sick, injured and underweight hedgehogs are rescued in the UK every year. Rescue can save a hog from death or suffering. Once nursed back to health, or just fattened up, most hedgehogs will be released back into the wild. But can these hedgehogs go on to lead successful lives in the wild? Does rescuing hedgehogs work? The good news is that, surprisingly often, yes they can. 

Why Rescue Hedgehogs?

Hedgehogs in the UK and most of Europe are in trouble, their numbers have decreased dramatically in recent decades and in 2020 they were officially classified as vulnerable to extinction in the UK. 

The reasons why, after 15 million successful years on the planet, hedgehogs are suddenly in so much trouble are on the one hand quite complex and on the other shockingly simple. In essence, hedgehogs are in trouble because humans have destroyed hedgehog habitats and food sources, and introduced a whole range of life-threatening hazards into their world. 

At the same time, hedgehogs have captured our hearts like no other British mammal. and many people are keen to help. Hedgehog feeding stations and nesting boxes have appeared in gardens up and down the country.

Hedgehogs are the most regularly treated patients in animal hospitals and there are over 800 hedgehog rescuers registered with the British Hedgehog Preservation Society. 

Rescuers range from large well-equipped animal hospitals like Brent Lodge, who have the expertise and training to help the most seriously ill or injured hogs, to individual animal lovers like you and me, who might overwinter an autumn juvenile. 

We don’t know how many hedgehogs are rescued each year in the UK, but the number is likely to run into tens of thousands. 

An awful lot of time effort and money is spent on rescuing hedgehogs every year. And since many (if not most) of the illnesses and injuries suffered by hedgehogs are caused by humans, this seems entirely right and proper. 

But how can we be sure that all this effort and expense is really making a difference? To individual hogs and to the conservation of the species?

Why do Hedgehog Need Rescuing?

Some animals who are in trouble, particularly prey animals like rabbits, tend to hide away and mask their vulnerability. Hedgehogs in trouble, on the other hand, often become much more visible than their fit and healthy relatives: coming out in the daytime, staggering around, looking drunk or even seeming to sunbathe on the lawn. 

None of these behaviours is a good sign in a hedgehog. But they do mean that hedgehogs in trouble can be surprisingly easy to spot. Which may in part account for the sheer numbers that end up being rescued. 

There are four main reasons why hedgehogs get taken into care.

Sick Hedgehogs

Sick hedgehogs are a familiar sight for most rescuers. A sick hedgehog will often lack the strength to gather all the food it needs during nighttime hours and so still be out fighting for survival during the daytime. 

Illness may first be apparent through a very visible burden of parasites such as fleas, ticks or ringworm. Although these may worsen the hedgehogs’ condition they are quite often symptoms of more serious underlying issues. 

A sick hedgehog will almost always need specialist help from a trained rescuer, animal hospital or vet if it is to survive. 

Injured Hedgehogs

Though being hit by a car may almost always spell the end of the line for a hedgehog it’s amazing what serious injuries they can and do survive. 

Hedgehogs are accident-prone and living close to humans introduces a whole host of additional hazards into their lives. 

Victims of gardening accidents such as encounters with strimmers, or attacks from dogs or foxes may look horrifically injured. But hedgehogs are surprisingly resilient and prompt attention can often result in a full recovery. 

Orphans 

For the first six weeks of their lives, a baby hedgehog is heavily dependant on its mother and will almost certainly be unable to survive in the wild without her. 

But as we’ve seen, a  hedgehog’s life is hazardous and many mothers are injured or die leaving orphans in the nest. Nests may also be disturbed accidentally. In some cases, a mother may return to a disturbed nest and move her hoglets to a new home. In others, she may be scared off and abandon her young.

Distressed hoglets will draw attention to themselves by calling like baby birds, or by leaving the nest to try to search for food. Where the mother is definitely absent these hoglets will stand a better chance of survival if taken into specialist care. 

Underweight Hedgehogs

Being underweight is a serious and common problem for hedgehogs. As human activity has decimated invertebrate populations it has become more and more difficult for hedgehogs to gather the food they need to maintain a healthy weight.

RSPCA Hedgehog weight guide

During the summer months, an underweight hedgehog may be more prone to disease and infestation by parasites. And come the winter hedgehogs who have insufficient body fat will not survive hibernation. 

Fortunately, it’s relatively easy to fatten up otherwise healthy adult or juvenile hedgehogs. And this is where small rescuers and animal lovers across the country have a key role to play. 

Does Rescuing Hedgehogs Save Lives?

Absolutely. 

There is no mistaking that rescuing hedgehogs can be a heartbreaking business. Many will be brought in who are just too sick to recover. Others may seem to be on the mend then take a turn for the worse. 

At some times of the year, particularly in the autumn coming up to hibernation time, rescuers can feel overwhelmed by the sheer numbers of stick and skinny hogs being brought in. 

Some species of animals don’t respond well to human care, but hedgehogs do. We don’t have figures on how many rescued hedgehogs survive in the UK but this study of European hedgehogs rescued in the Czech Republic makes interesting reading. The study followed many hundreds of rescued hogs over a 10 year period and found that over 44% of those rescued survived with the vast majority being well enough to release back into the wild. 

The study highlights the remarkable resilience of hedgehogs and how worthwhile the work of rescuers is. 

Do Rescued Hedgehogs Thrive When Released?

But what happens to rescued hedgehogs when they are released into the wild?

Beyond easing the suffering of individual animals the aim (and the legal obligation) for rescuers is to release animals back into the wild. Where they can go on to do their bit for the conservation of the species. 

But does this really happen? Can a hedgehog who become used to human handling and feeding hope to survive in the wild? This concern goes double for orphans or autumn juveniles who may have spent the bulk of their lives in captivity and have very little experience of natural life at all. 

It’s a reasonable concern. For many years conservationists believed that the dangers of releasing many species of rehabilitated animals into the wild were too high. Both for the individual animals and for the wild population. 

It would be satisfying to know what percentage of rescued hedgehogs survive in the wild for a year, say, and how that compares to the survival rates for “wild” hogs. 

But that’s difficult to pin down. There have been several studies over the years, but limited funding means they have been relatively small scale and limited in time span. In addition to this hogs get lost, lose their radio trackers . . . There are figures, but in such circumstances, statistical validity isn’t the best. 

Instead, it could be more useful to look at what the studies tell us about the behaviours that indicate success or failure in released hedgehogs: 

• Will rehabilitated animals be able to find food, or will they starve to death?
• Will they have the skills to build nests?
• Will they be disorientated in the new environment, will be able to return to their nest sites?
• How will they interact with the local wild population?
• Will they mate and breed successfully?
• Will they be more vulnerable to predation?

Let’s look at some of these in more detail

Finding Food

A real concern for rehabilitated hedgehogs was whether, after spending time (in some cases most of their lives) having food handed to them, they would be able to find their own food and water in the wild. Having lived so much of their lives on a diet of dog food or cat biscuits would they even be able to recognise what they were supposed to be eating as wild animals?

The earliest studies into released hedgehogs carried out by Pat Morris found that released hogs dropped a large amount of weight during the early days after release. This was an alarming finding and it’s shown up in almost all subsequent studies. 

But the hogs weren’t showing typical signs of starving, they weren’t continuing to forage in daylight. In fact, their nightly outings were surprisingly short. 

After a time the hogs’ weight stabilised and remained stable. Researchers concluded that the released hogs were in fact just shedding excess weight they had gained during captivity, and establishing a healthy, wild weight. 

Nest Building

Nest building is another essential skill for a hedgehog. Most rescuers allow hogs in care to build a nest within their enclosures. But the nesting materials and the nest site are provided for them. Would released hogs be able to identify suitable sites and gather the nesting materials they needed?

Again, released hogs did well: they found nesting material and built nests in the normal way. As with all hedgehogs, mature adults did a better job of nest building than juveniles, But all the released hogs were able to construct a nest. 

Disorientation

Where hedgehogs are released into a site that is distant from where they were captured, or if they were very young when taken into care, will they be disorientated by the new environment?

Hedgehogs in the studies, having built nests, were able to relocate them on subsequent nights - a key indicator that they were not disorientated by the environment. 

Some released hedgehogs did choose to relocate, travelling up to 2 miles to new areas. It’s unclear why they choose to do that. But in one study it was observed that hedgehogs released into an area of farmland relocated to a more suburban setting. So it’s possible that hogs on the move were looking for areas of more favourable habitat. 

Interaction with the Locals

There have been concerns about how released hedgehogs might interact with the local hedgehog population. Would there be fighting? Or would they get along? 

In all the studies conducted there has been no evidence of undue aggression between local populations and released hedgehogs. 

Of course, hedgehogs are solitary creatures and though they have home ranges they’re not territorial, they tend to avoid each other. So fighting is rare other than over rich sources of food, like feeding stations, or during the mating season. 

So what about mating? Surely this is the ultimate test of how well rescued hedgehogs get on in the wild. 

Mating and Babies

And yes, in several of the studies released hedgehogs were observed engaging in courtship behaviour with wild hogs. Some studies went on long enough to identify that female released hogs were pregnant. 

If a rehabilitated hedgehog can not only survive, but go on to mate, then all that hard work really is worthwhile. 

Prone to Predation

Another concern is that rehabilitated hogs may have lost their “street smarts” and be less wary of predators or natural hazards than their wild cousins. 

Again, no evidence has been found that rehabilitated hogs are any more prone to predation or accident than the population in general. 

Yes, post-rescue hogs in the studies were killed by badgers, by cars and other hazards. But this is only to be expected. Hedgehog mortality in the UK is 30% per year - it’s a dangerous world for hedgehogs.

Habituated to Humans?

The final concern is that rehabilitated hedgehogs may have become habituated to humans, and less wary of us than a wild animal should perhaps be. 

This seems to be born out. Pat Morris notes that some hogs had become so used to his team that they barely bothered to curl up for weighing. 

Thankfully deliberate human persecution of hedgehogs is not so common in the UK these days. So this might not be so much of a problem as it once was. But still, it seems like good practice to minimise human contact as much a possibly whilst an animal is being cared for - tempting though it may be to want to spend some time with them!

This article gives a very good in-depth look at the research. 

Planning for a Successful Release

It’s also clear that careful planning for release can be key in determining a hedgehogs chances of survival in the wild. And releasing or abandoning an animal into unsuitable conditions could be considered animal cruelty. 

Location, Location Location

Whilst lots of rescuers aim to release hedgehogs close to the place where they were found if possible this may not be as important as we have thought. 

The research has shown that hedgehogs adapt surprising quickly to new environments, don’t suffer from disorientation and don’t tend to have a homing instinct that pulls them back to where they first came from. 

So perhaps it’s more important that hedgehogs are released into areas that are rich in suitable habitat, and have an existing hog population. Parks, golf courses and areas of large, interconnected gardens could be preferable to modern farmland. 

Safety First

Life is dangerous for hedgehogs and once released into the wild there is no way of protecting them from all the hazards they are likely to encounter. 

But hedgehogs released away from major rounds and areas of dense badger population stand a better chance of survival. 

On these counts, suburban areas score well again as potential release sites. 

Good Condition

Rescuers will do their best to ensure that hedgehogs are only released once wounds are healed and illnesses and infections are dealt with. 

But beyond that weight is the most important factor to consider. Being released at, or a little above, a healthy weight was seen to be a very important factor in determining a hedgehogs chances of success at any time of year. 

Old injuries need not prevent a hedgehog from returning to the wild once healed. Hugh Warwick in his Hedgehog Book gives examples of hedgehogs doing well in the wild with missing legs or eyes. Even injured animals can often be returned to the wild.

Soft or Hard Release?

It’s become popular to “soft release” rehabilitated wildlife in a way that eases them gently into their return to nature. 

In the case of hedgehogs, this generally means giving them access to nest boxes and food at the release site. 

In all of the studies, the released hedgehogs totally ignored these kind gestures - typical hedgehog!

It is wonderful to see such levels of confident independence in newly released hogs. But it’s still worth putting out the food and nest boxes, other local hogs may well welcome them. 

Prevention is Better Than Cure

All the research indicates that hedgehog rescue does make a real difference. Not only to the life of individual hogs but also to the future of the species. 

It’s difficult to find accurate numbers, but in the UK thousands of hedgehogs will be saved each year by hedgehog rescue centres and go on to have successful lives in the wild, breeding and raising the next generation. This is incredibly important work. 

But there is only so much that rescuers, almost all volunteers, can do. So it falls to all of us to do what we can to keep our hedgehogs safe and healthy. 

• Offer food and water
• Provide a hedgehog house for nesting and hibernation. 
• Link your garden to others with a hedgehog highway.
• Keep a hedgehog friendly garden.
• And support the work of organisations like the Wildlife Trusts in restoring our countryside to a state that can support hedgehogs and other wildlife. 

Thanks for reading. We hope you’ve found this article interesting and if you have hedgehog rescue questions or stories to share we would love to hear them. Leave us a comment below.