Why Do Hedgehogs Have Late Litters?

Every time I spot a poor little skinny hedgehog out and about in November, I ask myself why? After 15 million years why haven’t hedgehogs stopped having babies so late in the year when they stand next to no chance of surviving the winter? It seems like a massive evolutionary fail: nature at her most cruel. But when you take a closer look, the picture may not be as bleak as it seems. 

Why Do Hedgehogs Have Late Litters?

The vast majority of adult female hedgehogs start the courtship process pretty much as soon as they come round from hibernation in the spring. The result is a litter of babies in the early summer – June or July. These hoglets have a good few months to grow up and fatten up before hibernation in the autumn.

.

Once the first litter are weaned, over 80% of female hedgehogs will start on a second litter. These hoglets will be born much later in the year—any time from August to November.

The Problem with Late Litters.

The problem with late litters is a double one. 

First, the hoglets, born late in the year, have very little time to put on the weight they need to survive hibernation. To safely go into hibernation, a hedgehog must lay down a good store of fat to give it the energy it needs to see it through the long winter months when it won’t be eating.

Hoglets weigh just a few grams when they are born. They are tiny. To safely hibernate, they need to weigh between 500 and 700 grams. That’s more than a can of beans and takes them to the size of a small loaf of bread. 

For hoglets born in September or later, there is very little time for them to do all the eating they need to before their natural food sources dry up and the weather turns too cold for them to be out and about. 

The result is that they will hibernate before they have enough weight to see them through the winter and simply not wake up. 

Or they will keep searching for ever more scarce food in increasing frigid weather and die of exhaustion or hypothermia.

Hedgehogs do not breed in their first year. So, from an ecological point of view, a hedgehog that dies before hibernation has made no contribution to the survival of the species. A truly wasted life.

Added to the problems the Autumn Juveniles face, late litters put the mother at risk too. The process of nesting, being pregnant, giving birth, feeding and raising a family is exhausting. Females lose weight and condition. Females typically hibernate later than males, so they have the chance to get back to a good weight after raising hoglets. But a very late litter, or the early onset of winter, could compromise the mother’s ability to hibernate safely too.

So why do hedgehogs keep doing something that seems like such a bad idea for the survival of the species?

No Mating Season

Whilst most creatures have a “season” when they mate, hedgehogs, like humans, don’t. Hedgehogs are sexually active pretty much all of the time that they are not hibernating. 

It used to be thought that only females who had failed to have an early litter “tried again” later in the year. But more recent research has shown that over 80% of adult female hedgehogs will have a second litter. 

Hedgehogs in New Zealand’s North Island, who don’t hibernate because the weather is so mild, often have 3 litters per year.

So it looks like hedgehogs are just programmed to keep mating unless they are hibernating.

It’s a Numbers Game

In nature, the purpose of each animal is to breed and contribute to the continuation of the species. 

The younger a female can produce, the greater the chances of her genes being carried into the next generation. 

And although Autumn Juveniles, the products or late litters, may not have much chance of making it through the winter, some of them certainly do. 

So for the female, the late litter is a risk worth taking, even if it is a risk to her own life.

Not Such Bad Odds?

Encouragingly, a recent study by Toni Bunnell has shown that the odds may not be so badly stacked against autumn juveniles as we thought. 

In a study of healthy juveniles brought into her rescue centre, Toni found that autumn juveniles put on weight significantly faster than hoglets born earlier in the year.

Further research is needed to find out exactly why this is. But theories so far suggest it could be due to changes in daylight hours and temperature signalling the onset of winter and stimulating the hogs appetites. 

Whatever the reason, this research shows that hoglets in late litters may have a better chance of survival than we had thought.

Not a New Problem

When I see a struggling hoglet in the autumn, I can’t help seeing it as part of the reason why hedgehogs are endangered.

But of course, it’s not. Hedgehogs have probably been having late litters for 15 million years. It is undoubtedly sad that so many young hogs die each year. But it’s not a new phenomenon. It’s part of the hedgehog’s natural life cycle and not part of the reason their numbers are declining so much.

A New Opportunity?

Whilst autumn juveniles have probably been around for millions of years, human hedgehog rescuers and hedgehog champions are a new thing. 

A skinny hog out in the autumn here in the UK now stands a good chance of being spotted by a helpful human: taken into care and fattened up for hibernation, or cared for for the whole winter

This has to mean that increasing numbers of juveniles who, if left to nature would have died, are now surviving their first winter. And then having the opportunity to breed and do their bit for the survival of the species. 

So when we help those skinny little autumn juveniles, we are not just helping to undo some of the damage mankind has done to hedgehog kind. We are doing something that has the potential to make a massive difference to the survival of the species. 

We hope you enjoyed this article and found it interesting.

Do you have thoughts or questions for us? We would love to hear them? Leave us a comment below.

And for more hedgehog reading check out our full library here.

SHARE ON

Share on facebook
Share on twitter
Share on pinterest
Share on email
Share on print

4 Responses

  1. I have a hedgehog in my garden that I think may be having a late litter as I have seen it at different times of the day carrying grass, straw and leaves into a sheltered overgrown part of my garden.

    If this is the case, is there anything I can do to help increase the hoglets chances of survival? I will be buying another hedgehog house so there will be a couple in the garden and I am creating some piles of branches but I was wondering if putting out more food, for a longer period would also be useful?

  2. I have a bird feeding cage to keep out the larger birds. For two days I saw a hedgehog squeeze through and eat the food. It was about 4 pm. Does this mean the hedgehog was too small? Should II start to put hedgehog food in the cage at night or will this just feed the mice. I did buy a predator proof house and put food in it but I suspect the cats of eating it.

Leave a Reply

Your email address will not be published. Required fields are marked *

Hedgehogs

Do Badgers Eat Hedgehogs? Do They Threaten Hedgehog Survival?

Yes, badgers do eat hedgehogs. Badgers are the hedgehog’s main predator in the UK and whilst hedgehog numbers are in drastic decline badger numbers have doubled since the 1980s. Early studies have shown that where badgers are culled hedgehog numbers bounce back remarkably. Yet the British Hedgehog Preservation Society is clear that badgers aren’t to blame for the plight of our hedgehogs.

Read More Now »
Hedgehogs

Wildlife Friendly Slug Pellets – Do They Exist?

Traditional slug pellets, made using metaldehyde are now banned from manufacture in the UK and you’ll be committing a crime if you use any old ones in your garden after March 2022. Most of the slug pellets now for sale in the UK use iron or Ferric Phosphate as their active slug killing ingredient. They are often labelled as organic, but are they really wildlife friendly slug pellets, and safe to use around pets and children?

Read More Now »
Where do garden birds sleep
Garden Birds

Where Do Garden Birds Sleep At Night?

Though our garden birds spent their days flitting through low branches, hopping around the lawn and handing off our feeders this isn’t where they choose to spend their nights. All of these places would be far too exposed to weather and predators to offer a good nights sleep. so where do the birds go at night?

Read More Now »
help baby birds in your garden
Guinea Pigs

How To Help Baby Birds In Your Garden

Seeing, or more likely hearing the first baby birds in the garden each year, is such a treat. But what if you see a young bird without its parents? What should you do, and how can you help? In this article, we will take a closer look at how you can help baby birds in your garden. When you need to intervene and lend a hand, and when it’s better to let nature take its course.

Read More Now »
Hedgehogs Need Our Help

Get Awesome Hog Content Every Week

Plus discounts and Special Offers