Matt Hayes, Research Assistant writes:

This set of posts will look at different groups of common butterflies as well as some historical species that have been lost or suffered declines. Read to the end for tips on how to support butterflies where you live.

Family Nymphalidae

Peacock, Aglais io

This charismatic butterfly is unmistakable due to the beautiful eye-spots that decorate its wings. When closed, the peacock butterfly’s wings keep it remarkably well camouflaged, with the undersides resembling tree bark, but if disturbed it can open them in a flash, presenting any would-be predator with a frightening display of large staring eyes.

They can couple this display with a startling hissing noise, which they produce by rubbing their wings together. The noise sounds more like a snake than something you would expect from a butterfly and can be a real shock if you are not expecting it.

The peacock is one of the longest-lived species in the UK and they overwinter as adults, often congregating together in sheltered locations such as sheds and tree hollows. The species is found all over the UK and Ireland throughout most of the year, usually emerging from winter slumber from March onwards, but it can be seen earlier if a warm spell occurs. Its beautiful black, spiny caterpillars live in groups and can be found feeding on sunny nettle patches throughout June.

Red admiral, Vanessa atalanta

This species is a regular visitor to gardens all across the UK and Ireland, but it is not a permanent resident, with individuals migrating to our shores every year from mainland Europe.

Like several other butterflies in this group, when winter approaches red admirals can be seen seeking out sheltered locations to overwinter. However, at least for now, it is thought that adults rarely survive our cold winters and most travel south to warmer climates.

Therefore, the first red admirals of the season will usually not have emerged in this country and some may have come from as far as Southern Europe and the Mediterranean. After arriving in the first warm days of spring, the species begins laying eggs almost immediately. Caterpillars can then be seen on nettle patches until as late as October, before pupating and emerging as adults.

Painted lady, Vanessa cardui

This species is another migratory butterfly, which visits the British Isles every year and performs an even more impressive journey than the red admiral. Its winter breeding grounds reach as far south as Sub-Saharan Africa. As these areas start to dry out due to rising spring temperatures, the butterfly is driven north and sets out towards Europe and the UK. Once here, it then breeds and can have multiple generations before cool temperatures drive it south again.  When the full scale of this round trip is considered it is little short of awe inspiring, as these butterflies cross deserts and can travel as far as 12,000km.

As with all migrant species, numbers of the painted lady fluctuate, but in good years it can be seen almost everywhere across the British Isles. Roughly every decade there is also a ‘painted lady year’ where millions of individual butterflies make their way to our shores. The last of these years was in 2019, with the previous one in 2009 being one of the largest on record.

Painted ladies can arrive in the UK as early as March and numbers continue to build from April – June as others join them. These individuals then breed, giving rise to next generation of adults peaking in July and August, with a further brood then possible in October. Thistles are used as the main foodplants.

Comma, Polygonia c-album

This unmistakable species has a striking, ragged outline, which helps it camouflage itself as a dead leaf. The name ‘comma’ comes from a white patch of scales on its underwing, which resemble the punctuation mark.

This species has had a remarkable reversal of fortune over the last century, which, in amongst all the stories of decline, provides an encouraging story of recovery. Climate change may be involved in its resurgence as it likes warm, sunny habitats.

The comma is found throughout woodlands, hedgerows and sheltered gardens across England and Wales. It can overwinter as an adult, with the earliest individuals re-emerging in March.  Adult butterflies can then be seen on the wing almost all year through to October. The most common foodplant is nettle, where you can see its fascinating caterpillars across most of the summer. These are splashed with black and white and are thought to mimic bird droppings to dissuade would-be predators.

Small tortoiseshell, Aglais urticae

This is a widespread species that can be seen in gardens throughout most of the UK and Ireland. There are normally two generations each year in the south, but there is only one in Scotland. After overwintering, adults in the south of the UK emerge during the first warm days of spring and survive into May, laying eggs on young sunlit nettles.

These hatch and, after the caterpillars have grown to full size, give rise to the year’s first new generation of adults in June and July. These then lay eggs, which in turn give rise to the second generation between August and October, which quickly hunker down to overwinter and repeat the cycle.

Species of the Past

Large tortoiseshell, Nymphalis polychloros

If you were to look out of your window 100 years ago you might have also seen the small tortoiseshell’s larger relative, the imaginatively named large tortoiseshell. Once a common sight across the woods of Southern England, the species underwent a dramatic decline and it is thought to have been extinct as a resident in the UK for over 50 years.

At best it is now an extremely rare visitor, immigrating from the Continent. Dutch elm disease destroying the larval foodplant, climate change and other factors have been suggested as reasons for its decline. It would have been seen on the wing for much of the year and overwintered as an adult, before mating and laying eggs in the spring to start off the next generation.

Gardening for the ‘aristocrats’

Larval foodplants:

The best thing you can do to support some of our largest and showiest butterflies is to resist the urge to ‘tidy up’ the edges of your garden and maintain a sizeable nettle patch in a sunny, sheltered spot. All ‘aristocrat’ species mentioned above can feed on these and if you want you can also add a little thistle into the mix, which is more readily used by the painted lady. This patch may appear prickly and unwelcoming at first, but it will support a wealth of wildlife in addition to your caterpillars, providing them with food and shelter. If you are worried about youngsters playing in the garden, there is a non-stinging variety that can be purchased. Alternatively, you could section the nettle patch off, so that it is still visible, and then search for caterpillars together in the summer.

As many of the species in this group overwinter as adults, they remain on the wing well into autumn and emerge early in the spring. You can help them by providing flowering plants at these times of year, when other nectar sources are scarce. A few springtime primroses and autumn rudbeckias will go a long way for butterflies looking to restock their energy reserves.

As winter approaches, you may also notice peacocks, small tortoiseshells and commas trying to make their way into your house. They will be looking for somewhere to hunker down and overwinter away from the elements. Central heating is likely to disrupt their slumber so outhouses like sheds and garages are more suitable. If you do find an adult butterfly inside your house, you can gently move it to one of these locations where it can safely see out the cold weather.

Avoid tidying up your outhouses too much over winter as you may disturb any butterflies that are resting there. However, if you are careful you can search for them. They will usually be in the darkest, sheltered corners up near the roof.

---

For more detailed information on gardening for butterflies and wildlife in general please see:

Butterfly Conservation (website)

The Wildlife Trust for Bedfordshire, Cambridgeshire and Northamptonshire (website)

For more detailed information on the butterflies of the British Isles please see:

Butterfly Conservation (website)

UK Butterflies (website)

The Butterflies of Britain and Ireland (Book):

Lewington, R & Thomas, J (2014). The Butterflies of Britain & Ireland. New Revised Edition. Oxford: British Wildlife Publishing Ltd.

---