Red Admiral Butterflies, do they hibernate in Britain?

November 11, 2014

in A selection of my garden wildlife videos, Gardening For Wildlife, Insects

More Red Admirals seen later in year by Garden BirdWatchers 

The British Trust for Ornithology,  (BTO) have a team of people working to monitor, not only birds but other wildlife in people’s gardens, known as  Garden Birdwatch.  In their latest newsletter “Red Admiral resurgence in gardens” Garden BirdWatchers have reported the Red Admiral (Vanessa atalanta) appeared in the highest numbers this year, with unprecedented numbers still being reported in October. I filmed one in my garden 15 Oct, but also saw one on 24th October, during a brief sunny spell. Such a beautiful butterfly, the Red Admiral, is a migrant from Northern Africa and continental Europe. It is not regarded as a resident species, although the immigrant females lay eggs here and it is their offspring that we see in the summer months. The caterpillars use common and small nettles as a food plant, with pellitory-of-the-wall and even hop may also be used. So whether your garden is in England, Ireland, Scotland or Wales, is along the sea shore, in the town centre or even the top of some mountains you may be lucky to see a Red Admiral!


Nurturing Nature Red Admiral butterfly


As many people will know, here in Britain mammals such a bats, hedgehogs and dormice truly hibernate. Insects do not hibernate in the strict scientific meaning of the word, they go into a dormant state, though for this article I will use the word most people associate with winter inactivity, hibernation! In fact some insects are most active during the winter months, such as the Winter moth, December moth and Spring usher moth. In my garden I saw one 24th October, the latest ever. What do you do if you find hibernating butterflies in your house?


 Hibernating  butterflies

It is known insects enter a dormant stage during winter, either as an egg, larva, pupa or adult. A few adult butterflies, namely the Brimstone, Large Tortoiseshell, Comma, Small Tortoiseshell and the noisy Peacock, do hibernate. However, sadly, the Large Tortoiseshell does n’t anymore in the UK as it is officially extinct! A few specimens have been found on the Isle of Wight and photographed by Mathew Oates.,  a National Trust naturalists. Some people find the Peacock and Small Torstoishell in their homes, garages and sheds. I have found Large Cabbage Whites on the inside of my garage roof, during the winter months. They were amongst some Large Cabbage White chrysalises and may have for all I know, emerged from them early during a warm spell and decided to stay there.

Hibernating Red Admirals- A myth?

For much of the twentieth century, although at one time they may well have been a resident, (Fox and Dennis), Red Admirals were considered to be incapable of regularly overwintering in Britain and Ireland and were regarded as immigrants, i.e. visitors that bred in warm weather as opposed to residents.  Indeed according to Thomas (2010) and again in his latest reprint (2014), “Although a few Red Admirals may seem to hibernate in the British Isles during mild winters, these generally settle in exposed places, such as on tree trunks or under branches and usually perish. It is likely that these are late emerging adults that become trapped after the onset of conditions too cold for flight. The few adults that are seen on sunny days from December to February are believed to result from late caterpillars that were able to develop in warm spots”. It is quite possible that this may once have been the case. New and more detailed research has now come up with more up to date information.

Increasing Red Admiral numbers

The recording of increasingly numerous Red Admirals from Citizen Scientist recorders from the long term United Kingdom Butterfly Monitoring Scheme  re-enforces the fact that their numbers are increasing, but this work does not tell researchers much about their phenology over winter period. (UKBMS operates Apr-Sept). 

Fortunately, the national recording scheme (Butterflies for the New Millennium) run by Butterfly Conservation, generates a huge amount of data, recorded by thousands of citizen scientists and professional recorders/researchers, throughout the year.



Red Admirals winter sightings 2006-07

Fig. 3 The distribution of V. atalanta records in Britain and Ireland during the period Dec 2006-Feb 2007. Dots represent the presence of at least one individual V. atalanta in each 10km x 10 km grid square of the British or Irish Ordnance Survey. (Fox and Dennis)

A new resident butterfly to Britain?

Using this data, Fox and Dennis (2010) studied Red Admiral occurrence in Britain in the winter.

There are several factors that have been considered in this study:

A huge amount of data recorded by of thousands of citizen scientists and professional recorders/researchers;

Significant increase of winter numbers over time;

Significant increase in winter distribution;

Increased winter survival;

Observations of larval activity, survival and development during the winter;

Winter observations of male territorial behaviour, courtship, mating and egg laying;


Climate change;

Substantial shift in the phenology of the butterfly.

The records of many thousands of Citizen Science recorders, with observed Red Admiral winter behaviour and recent climatic change,  Fox and Dennis state that under the right conditions, the Red Admiral can successfully reproduce here in the UK all year round and are now once again resident in Britain and Ireland.

Do Red Admirals hibernate?

As far as can be ascertained Red Admirals, do not hibernate. i.e. they don’t enter a long dormant stage as Peacock, Small Tortoiseshell and others do. They seem to simply roost on inclement days and fly around and get on with life on winter days when the weather is better.

Interested in a simple, non complicated Butterfly Conservation app for smartphones?   iRecord Butterflies App

Refs. Besides my own and experiences:

Fox, F. & Dennis, L. H. (2010) ” Winter survival of Vanessa atalanta: a new resident butterfly for Britain and Ireland?  Entomologist’s Gazette 61: 94-103

Thomas J & Lewington R, (2010) & (2014), “The Butterflies of Britain and Ireland” British Wildlife Publishing, Milton on Stour, Gillingham, Dorset.

Thanks to Richard Fox of Butterfly Conservation for his helpful input.

{ 33 comments… read them below or add one }

Marian November 11, 2014 at 8:15 pm

Hi George,
Our last sighting of the red admiral was on some late flowering Michaelmas daisy a few weeks ago. Seen a number of these this year, our glorious summer obviously helped. Let’s hope the winter is as favourable!….
Regards Marian


nurturingnature November 12, 2014 at 10:55 am

Hi Marian, Yes, Its nice to see them so late but the reasoning behind it, climate change, is really worrying. Cheers, George


William mckie December 14, 2014 at 1:07 pm

I had one in my bedroom this morning, woke me up flying round my head


nurturingnature December 15, 2014 at 11:09 am

What a lovely way to be woken up….. stars and butterflies!!! Cheers, George


Fiona January 1, 2015 at 2:44 pm

We have a huge red admiral moving around in the spare room. It stops and closes it’s wings. I have left a rotting apple in the room but how do we look after it until spring?


nurturingnature January 2, 2015 at 4:57 pm
Samantha October 23, 2015 at 7:19 am

I have a yellow buddleia davidii and the red admirals have been high in numbers this year, I have seen them still here this year, and photographed them on the 21st of October.
I would love to help them hibernate and my husband is going to make a hibernation house for them this weekend I know they might not use it but its worth a try right!
you can see my photos here

any advice on hibernation or helping them would be much appreciated


nurturingnature October 25, 2015 at 11:56 am

Hi Samantha, They hopefully wont hibernate in your house!1 As to making a home for them to overwinter, that may be a little difficult, but great if possible, especially if they survive! It may be difficult for you to signpost where you would like them go!! Mouse proof,dry,out of the wind, dark, sheltered, safe, cool, etc. these are attributes they may have to find themselves. Leave your garage, outhouse, shed, etc., window open… they may find that suitable. Thanks for sharing and nice photos! Cheers, george


Samantha October 26, 2015 at 11:04 am

thanks for your advice… we did make a hibernation house over the weekend even borrowed a router to make the slits, we are painting it today and then will be finding a good position for it and will keep my fingers crossed they Might use it,,, if not its a pretty addition to the garden was fun to make and we used up some scraps of wood we had so no cost either 😊
I will add a photo to my blog and let you know when I have xx


nurturingnature October 26, 2015 at 10:14 pm

Yes that would be nice. If you are successful that would be fabulous! Thanks, George


Victoria November 23, 2015 at 4:51 pm

Hi there, I’ve retrieved a pupa from my garden that blew off the nettles in the storms and I know we are due some heavy rain tonight so it’s currently on my kitchen table, what can I do with it? I think it may be a red abmiral.

Thank you


nurturingnature November 24, 2015 at 10:14 pm

Hi Victoria, If you have any thick vegetation, such as ivy, similar try putting it there out of reach from mice….I would take it outside pretty pronto as it will be too warm indoors. Thanks for sharing, George


Helen July 24, 2016 at 3:06 pm

I appear to have a family of red admirals in the garden and have seen 3 today and most of last week. They have been seen regularly every day over the last week.



nurturingnature July 26, 2016 at 7:24 am

How lovely, I have not seen many at all this year Tele. Thanks for sharing. Cheers, George


Helen July 26, 2016 at 9:16 am

Just say I’m in the Staines on Thames area on the river side.


nurturingnature July 27, 2016 at 9:10 pm

Saw 1st RA in the garden today!Cheers, George


Michelle November 8, 2016 at 10:47 pm

I have just found a red admiral flying around my light, 10.40pm 8 nov 2016 it has gone cold recently so think its come in to warm up. Let me know how best to help it in the winter. Should I let it carry on living in my house. I have house plants but not many flowers inside. Should I let it out, on its way to do what nature intended. Thku


nurturingnature November 9, 2016 at 4:00 pm

If you can gently gather it up and place it outside in a shed, garage, similar on a roof, wall, ceiling etc, away from predatory mice, in a cool dark place. HTH Cheers George


Rosy Jones November 11, 2016 at 4:16 pm

A red admiral (possibly two) was seen flying from a beech tree in the sunshine in Nork Park (TQ239590) today (11/11/2016)


nurturingnature November 11, 2016 at 11:06 pm

Wow! Lets hope it finds a suitable hibernation site before the weather declines. Thanks for sharing. Cheers George


shelley November 16, 2016 at 10:40 am

I just observed a red admiral flapping lazily around my garde (today is 16th nov) I have never seen one out this late though it is a freakishly mild sunny day.
At first I thought it wasjust positioning itself on various nettle patches to catch sunlight & warm itself but on closer observation it was laying eggs! in november…has anyone else observed this or is this unusual behaviour?


nurturingnature November 16, 2016 at 10:04 pm

Hi Shelley, I have not seen this myself as the weather here has not been favourable. Go to Butterfly Conservation web site and email them re this…Richard Fox may also be interested he works for them. Thanks for sharing, George


w miller January 22, 2017 at 9:17 am

we live in aberlour morayshire and for 20 years now we have noticed red admirals appearing in our basement cellar now in . january 2017 .I think they are in the space behind the old plasterboard am I DOING RIGHT BY OPENING THE DOOR AND SETTING THEM FREE IN THIS MINUS 4 WEATHER OR KEEP THEM INSIDE.


nurturingnature January 25, 2017 at 11:41 am

Keep them inside unless they willingly go outside. Its early for them to be awake and you being where you are there will unlikely be enough food around them to survive. HTH, Cheers, George


w miller January 25, 2017 at 12:07 pm

I forgot to say we also have just found a small tortoiseshell and we put it in a cardboard box open at the top. We put it at the back of our cellar where it is cooler, is that ok. Many thanks. Dusty.


Lindsay Mason September 9, 2017 at 9:13 am

As I type I am watching around a dozen Red Admirals coming and going to the fruit that I have hung in my Elder. I originally hung up a string of halved apples for the birds (which totally ignored them!) and then, as the apples fermented, began to see the odd butterfly landing there for a feed. I now have apples, oranges and pears, in various stages of ripeness, hanging up and there are more butterflies coming to them all the time. It’s wonderful to see them fluttering about and then gorging on the fruit – and probably getting a little tipsy too! How long can I expect to see them visiting and will they survive the autumn/winter? Many thanks, Lindsay


nurturingnature September 17, 2017 at 7:37 pm

Lindsay, great thanks for sharing this. I hope more people do this, the butterflies will either fade away or hibernate. Cheers, George


Gina September 24, 2017 at 2:30 pm

On 29th August I found a Red Admiral on the grass near to some nettles in my garden. One wing was perfect but the other was very stunted. I picked it up and put it in foliage near the nettles. What could have caused this ?


nurturingnature September 27, 2017 at 7:45 pm

That Gina is very difficult to answer! Could be a number of reasons…perhaps it was a late merger from a cocoon and needed time for the other wing to open up. Who knows? Cheers, George


Kim October 29, 2017 at 4:43 pm

For the past couple of weeks, when walking on the north shore of the Isle of Wight, by the Solent, I have seen individua Red Admiral butterflies flying by the water’s edge. Are they migrating?


nurturingnature October 30, 2017 at 7:21 pm

Nice question Amy, you could well be right. Thanks for sharing, George


Karen November 17, 2017 at 8:00 am

I was a stallholder in our local town, Orpington, Kent, for their Christmas Lights Switch On yesterday, 16th November. A Red Admiral butterfly started fluttering in and out of my gazebo from about noon and eventually settled on one of my inside roof straps about 2pm where is stayed until I took the gazebo down at 9.30pm. Not knowing what to do with it I put it into a large container with loads of air holes and a piece of cut up orange. Glad we did as there was a heavy frost overnight. Plan to release it later when it warms up. Hopefully it will have a little longer life.


nurturingnature November 17, 2017 at 7:00 pm

Thanks for sharing Karen. Good luck with the release! Cheers George


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