Big Issue Vendor

How butterflies use shock and awe to dazzle

The secrets of our garden visitors have only recently been discovered by scientists 

We humans were born for adventure. But this summer, many of us are choosing to stay closer to home instead of navigating the complexities of a Covid-dominated summer.

Despair not: adventure abounds. It’s there in your own back yard or apartment balcony. Look about you, biologist EO Wilson suggests, at the little things that run the earth.

A few years ago, my husband and I ripped up our grass and replanted with native wildflowers. Now we have all the drama we can handle. Birds warring over mates and territory. Bees busy nectaring.

Butterflies fluttering about. You can go on a butterfly safari, just by getting some native flowering plants and finding a comfortable seat in your garden. Because if you plant it, they will come. To you. No need to go anywhere. Just place butterfly-friendly plants around you, even if only in pots on a balcony. The butterflies will find them. Then just sit back, watch, enjoy and learn.

Because there’s more to butterflies than meets the eye. Consider the butterfly proboscis. This long, thin tube in front of the butterfly’s head coils and uncoils. When the insect is flying, it’s usually coiled. But when the insect probes a flower for nectar, it uncoils.

We’ve long believed that this appendage is like a drinking straw and that butterflies “sip” nectar. Wrong. By using newly developed super-powerful microscopes, scientists have seen that the proboscis is indeed hollow inside. But it has too many holes to allow for “sipping”. Imagine trying to sip – with a flute or an oboe.

Instead, the proboscis is like a blotter, a paper towel or a sponge. The butterfly lays the uncoiled proboscis atop the material it craves. The microscopic holes running along the tube absorb whatever is there, using simple capillary action. This nourishment acquisition instrument can even send liquid out of the tube. Watch your butterfly “puddle,” laying its proboscis atop something like a stone or just dirt. There are likely nutrients there that the butterfly needs, like salts. Liquid exudes from the proboscis and dissolves those salts. Then the nutrient-filled liquid reabsorbs for the butterfly’s use. Put a rock or two in your garden. Watching is fascinating. During this process butterflies spread their wings. You may well get some very showy photographs.

Think about the glittering scales you’re enjoying. The undersurface of a butterfly’s wing is often covered with scales that contain pigments that are dull brown, tan, grey. They are uninteresting for a reason: They provide some incredible camouflage when folded, fooling predators into thinking that the butterfly is merely a dead leaf.

But the scales atop the wing have an in-your-face razzle-dazzle of joyful colour, a glittering showiness that begs for your attention. This is shock-and-awe strategy: If hiding didn’t work, then hypnotising you with lavish beauty might do the trick.

How do they do that? These iridescent scales don’t get their colour from pigments, but rather from intricate infinitesimal shapes on the scales’ surfaces. These shapes bend light in a variety of ways that produce what we humans perceive as various colours, researchers have only recently discovered.

The blue of the fabled blue morpho, for example, derives from row upon row of Christmas tree-like structures within only one scale. The green of other butterflies derives from scales that contain gyroid shapes on their surfaces.

These structures are invisible to the human eye, but you can see their effects. When you sit in your garden watching butterflies manoeuvre in the air, their colours shift and change. Via the tiny surface structures, their scales are bending the sunlight, just as soap bubbles or oil sheens do.

You might also see the butterflies interact with each other. You may watch males compete for access to flowers, plenty of space, and – you guessed it – the attentions of females. Male butterflies often chase other males in order to protect their territories.

But not to worry: the male doesn’t have all the control. Science has recently discovered that females are perfectly capable of rejecting the attention of males if they find him uninteresting. Like us, she loves beauty. She wants him to look good, at the top of his game. If she finds the male dull, she will firmly send him on his way.

Who needs long-distance travel when all the drama of the natural world is right there. All you have to do is set the stage, then take the time to look.

The Language of Butterflies by Wendy Williams is out now (Simon & Schuster, £20)