This week we’re celebrating all things butterfly by listing 5 facts you might not have known about this majestic metamorphic insect. We hope these facts will inspire you to take part in the Big Butterfly Count – a survey you can do in your own garden or local green space to help Butterfly Conservation keep track of species of butterfly in the UK.
So, without further ado, did you know that…
1. Butterflies can’t fly if they’re cold
Butterflies actually need to maintain a surprisingly high body temperature if they want to fly around. For a butterfly to operate at an optimal level, its body temperature needs to be around a staggering 30°C (86°C). If it is too cold, the butterfly will be rendered completely immobile.
Maintaining a high internal temperature is a tough task for an insect with cold blood. Butterflies warm up by ‘basking’ in the sun, staying still on vegetation with their wings spread in direct sunlight. Their wings contain a network of small capillaries and this activity heats the blood in butterflies’ veins, allowing for transport of warmed blood throughout their small bodies.
2. Butterfly wings are actually transparent
First of all, butterflies don’t have just two wings, they have four (made up of two hindwings and two forewings). These wings are made up of two layers of the protein chitin, sandwiching a layer of capillaries. The chitin is covered with modified hairs called ‘scales’ that contain pigments (such as our very own melanin, found in brown butterflies) that reflect light in different colours. Over time, some of these colourful scales will rub off, exposing the transparent membrane.
It is a myth that rubbing these off by hand will prevent butterflies from flying, however it might leave the translucent membrane more prone to tears, which might hinder flight. Butterfly wings are very delicate so make sure to avoid touching them if possible.
Note: The Glasswinged butterfly (Greta oto) provides an example of what butterflies might look like if the scales on their wings did not reflect light in this way. You won’t see one in Britain as they are mainly found in Mexico, Panama and Colombia, but it’s worth checking out nonetheless.
3. Butterflies taste with their feet
Butterflies have senses of taste, smell and touch and their taste receptors are actually located on their feet. More precisely, they use chemoreceptors on the tarsi to detect different chemicals when they land on flowers and plants.
Actually, the reason for these sensors are more complex than just detecting sweet nectar. A female butterfly will use its sensors to determine whether its caterpillars will be able to eat the leaves they have landed on. Using its receptors, female butterflies can detect both attractive and toxic traits of plants in order to choose the most suitable plant for their eggs. For this reason the taste sense in some species of butterfly is only switched on in females.
4. Butterflies don’t actually eat anything
That’s right, butterflies don’t eat anything and don’t possess the mouth organs to do so. They can only drink, using a long protruding tube called a proboscis. In fact, this is one of the first parts of a butterfly’s body to develop during metamorphosis. You may see butterflies fresh from metamorphosis testing out their proboscis by uncoiling it and coiling it back up again repeatedly.
Butterflies mostly drink nectar as you would imagine, but they also drink from muddy puddles, rotten fruit and even dead animal carcasses. Nectar provides them with the glucose they need for energy, but other liquids are necessary at times to provide them with minerals and salts.
Interestingly, they don’t defecate either. Although caterpillars eat almost constantly and excrete frequently, butterflies do not have the means to do so. Occasionally a butterfly drinks too much nectar and sprays a fine liquid from their abdomen, but this liquid is almost pure water.
5. It’s really easy to attract butterflies to your garden
You’ve probably heard that Buddleia, aka butterfly bush, is the best plant for attracting butterflies to your garden, but do you know why? The answer lies in the fact that its nectar is favoured by the largest number of butterfly species. Eighteen species in total are partial to this Victorian invader, including some you might see on St Nicks, such as Comma, Gatekeeper and Peacock. This is part of the reason why we have so much Buddleia on St Nicks Nature Reserve, particularly on the Butterfly Walk.
There are other popular, and less invasive, plants favoured by different species of butterfly, such as Lavender or Oregano. Adding more of these butterfly-friendly plants to your grden will help the nation to develop green corridors, allowing for previously isolated butterfly populations to move to new areas with better food sources in order to colonise and breed. This could help to secure the future of our butterflies.
Bonus facts: finally for your pleasure, here are 5 of our favourite butterfly species that you can look for right now!
Small Skipper (Thymelicus sylvestris)
These butterflies are relatively small, but they are interesting because they straddle the blurred line between butterfly and moth. Like moths they have thick, hairy abdomens and slightly duller colouring.
The most unusual trait of a skipper is the way it sits at rest. Much like a moth it rests with its wings in spread out, however it sits with its orange and brown forewings angled above its hindwings in a rather unusual fashion.
Ringlet (Aphantopus hyperantus)
Right now, somewhere in the UK, a keen butterfly etymologist is guaranteed to be talking about the high number of Ringlets that have been sighted this year. It’s been an amazing year for them and York has been no exception. Although at first you might confuse them with other species from the brown family, such as the Meadow Brown or the Speckled Wood, if you look closely you can identify them by their distinctive ringlet shapes on the hindwings and white fringes on the wing edges.
Because of the dark colouring of ringlets, they are able to warm up much more quickly than other species, allowing them to fly on overcast days.
Comma (Polygonia c-album)
The jagged and uneven edges to the wings of this butterfly make it extremely distinctive. The colour of the underside of the wing makes it look like a withered leaf, allowing it to rest within dead leaves when hibernating. The name comes from the small white marking on its underside, which is shaped like a comma. Although more commonly spotted in summer, you might also see the Comma awaken on a warm winter’s day.
Have a look on around the edges of the woodland areas on St Nicks, where you might find the Comma feeding on thistle, bramble or knapweed.
Small Tortoiseshell (Aglais urticae)
Small Tortoiseshells may be common, but their courtship methods are rather unusual. Male Tortoiseshells set up territories close to nettle patches, which is the main food source for Tortoiseshell caterpillars. The male will then “drum” his antennae on the hindwings of the female, making a sound that, although feint, is audible to the human ear. The female will fly a little distance away, the male will catch up and the process repeats itself. This can go on for several hours.
Although once thought of as one of the most common butterflies to see in Britain, Small Tortoiseshells have suffered a harsh decline over recent years. In fact its relation the Large Tortoiseshell, which was a common sight in Victorian Britain, is now considered to be extinct in the British Isles, with only 150 recorded sightings since 1951.
Common Blue (Polyommatus icarus)
This is the most common of the blue butterflies within the Lycaeindae family, known for their rapid flight. Males have wings with a distinctive blue upperside and spend a lot of time patrolling their territories looking for females. In contrast, duller, browner females have a more sedentary lifestyle, preferring to drink, rest and lay their eggs. In the evening Common Blues are known to form communal roosts with several individuals perched together, sometimes on the same grass stem.
At St Nicks you might look for this butterfly in the summer meadow feeding on Birdsfoot Trefoil.
All of these butterflies have been found at St Nicks in recent months, so if you come along to our Summer Nature Walk on 9th August you might just see them for yourselves!