by Dr Hannah Rowland, Max Planck Institute for Chemical Ecology, and Dr John Skelhorn, Newcastle University
Many prey species have eyespot markings that are believed to ward off predators. But how, and does a predator’s angle of approach make them less effective? Dr Hannah Rowland and Dr John Skelhorn write for Frontiers about their research, published today in Frontiers in Ecology and Evolution, into how these protective patterns on moth wings convince birds it’s not worth attacking the insects.
Butterflies and moths with eye-like spots on their wings, called eyespots, have fascinated people for centuries. These colorful and striking patterns are more than just decoration – they serve an important purpose. In this article, we’ll explore why some butterflies and moths have eyespots, which species showcase these markings, and how eyespots help defend against predators.
Why Do Some Butterflies and Moths Have Eyespots?
Eyespots likely evolved to startle and intimidate predators When a butterfly rapidly opens its wings, a predator is confronted with what looks like a pair of large menacing eyes staring back. This flash of color surprises the predator and makes the butterfly seem dangerous, even though it poses no real threat. There are a few leading theories as to how eyespots protect butterflies and moths
Intimidation
Eyespots mimic the eyes of the butterfly or moth’s predators, like birds, lizards and frogs. The sudden appearance of large lifelike eyes makes the predator hesitate, allowing the insect time to escape. Some eyespots enhance this effect with white or light blue centers that resemble light reflecting off a real eye.
Deflection
Eyespots near the edges of the wings may divert attacks away from the insect’s head and body. A bite to the wing margin harms the butterfly less than a direct strike to its vital organs. This improves its chances of survival and escape.
Mimicry
Some eyespots imitate the pattern and colors of animals the butterfly shares its habitat with, like snakes. This startles the predator and causes it to recoil briefly. Even just a momentary pause gives the vulnerable insect time to fly away unharmed.
Butterflies and Moths With Stunning Eyespots
Many butterflies and moths across the world feature eyespots. Here are some of the most vibrant and eye-catching examples:
Peacock Butterfly
This European butterfly has four spectacular eyespots, one on each wing. The spots have metallic blue, brick red, yellow, and black rings. When a bird attacks, the Peacock butterfly flashes its wings open suddenly, surprising the predator with what looks like the eyes of a much larger animal.
Buckeye Butterfly
Several Buckeye butterfly species showcase eyespots, including the Common Buckeye and Gray Buckeye. They have two large eyespots on each wing, flanked by two smaller spots. The eyespots likely serve to startle and distract predators. Their position along the outer margins of the wings suggests they may also draw attacks away from vulnerable body parts.
Io Moth
The Io moth is a large North American species that dazzles with its bright yellow wings and hindwing eyespots. The spots have vivid black, red, and white rings for maximum effect. The Io moth flies at night so the eyespots are an especially important defense when birds and bats attack in dim light.
Polyphemus Moth
As one of the giant silk moths, the Polyphemus has a six-inch wingspan and prominent eyespots to scare off predators. The curved teardrop-shaped spots on its hindwings resemble gleaming yellow and black owl eyes. This likely deters birds and small mammals from attacking.
Madagascan Moon Moth
With its huge fuzzy wings and striking eyespots, the Madagascan Moon moth resembles an owl in flight. Enemies see the “eyes” and are startled into thinking a dangerous predator is approaching. This brief hesitation allows the giant moth to escape despite its 100mm wingspan making it an easy target.
Eyespots on Caterpillars and Other Animals
Some caterpillars and animals besides insects also use eyespots to defend themselves by mimicking predators and scaring off enemies. Here are a few examples:
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Spicebush swallowtail caterpillars have yellow and black eyespots on their heads to resemble snakes and startle birds.
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The foureyed butterflyfish has one dark eyespot on each side of its tail to divert attacks by larger fish. Predators go for the spotted tail rather than the more vulnerable head.
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Peafowl display extravagant eyespots on their tail feathers, which they flare out to intimidate rivals and impress potential mates during courtship.
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Sand lizards are covered in eyespots to mimic larger, dangerous reptiles and make predators think twice before attacking.
The Eyes Have It
Eyespots have evolved in many butterflies, moths, and other creatures through natural selection. They provide an effective defense for vulnerable species against a wide range of predators. The variety of patterns we see today demonstrates how adaptable and inventive nature can be. When you spot eyespots on an insect’s wing, take a moment to appreciate this visual marvel of the animal kingdom.
Creating the ultimate death stare
We tested the idea that forward-facing eyespots appear to gaze at predators by pitting artificial moths against newly hatched domestic chicks. We created the moths by pinning paper triangles over mealworms – a favorite food of chicks. The paper triangles were printed with eyespots in one of three configurations: either perfectly concentric circles, or with the center circle nudged to the right or left. All of the prey were designed to be equally conspicuous to the predators. To us, these appeared to gaze directly ahead or to one side. Would the direction of gaze affect the chicks’ motivation to attack?
supplied by Hannah Rowland and John Skelhorn
Next, we built three miniature catwalks (well, actually, chickwalks) to lead the chicks towards the moth. One led directly towards the prey, and the two others directed the chicks to approach the moth from either the left or right. We timed how long it took a chick to approach and attack each type of moth from each of the three directions.
Chicks were slow to approach from the left when the moth’s eyespots were shifted to the left, and slow to approach from the right when the moth’s eyespots were shifted to the right. However, when chicks approached these moths from the opposite direction, they quickly approached the moth and ate the mealworm. The chicks were slow to approach the moths with concentric circle eyespots from all three directions.
How art mirrors life when it comes to moth wings
Have you ever felt that a person in a portrait is watching you, their eyes following you about a room? This optical illusion is known as the Mona Lisa effect, after Leonardo da Vinci’s famously enigmatic painting. When artists paint their sitter’s eyes with the pupils perfectly centered, no matter where visitors stand – to the left, right, or in front of the painting – eye contact is guaranteed. Nature seems to have hit upon the same idea. But in the animal kingdom it can be a matter of life or death.
Many species of fish, butterflies, moths, praying mantids, and beetles have paired circular markings on their bodies that often appear to resemble eyes. Eyespots can deflect a predator’s attention to a prey’s non-vital body parts (a prey is much more likely to survive a bite to its tail than its head). Eyespots also can be intimidating and deter predators from attacking at all.
One explanation for this is that predators mistake eyespots for the eyes of their own predators. If this is the case, then eyespots that seem to look directly at them would be the most threatening. Much like the portraits whose eyes seem to follow you around the room, eyespots might appear to maintain eye contact with predators no matter their vantage point. On the other hand, if eyespots were displaced either to the left or right, they would only protect prey from predators approaching from that direction.
Another explanation is that eyespots have nothing to do with eyes. Predators could be deterred not because eyespots look like eyes, but simply because they are patterns that stand out. There are many conspicuous colors and patterns in the animal kingdom that are aversive to predators but look nothing like eyes – for example, the red and black patterns of ladybirds. Humans might perceive eyespots to look like eyes, but that doesn’t necessarily mean that predators do too. They may simply see ‘scary’ conspicuous markings.
12 Butterfly Species with Eyes on Wings (Eyespots) | Butterfly Adaptation
FAQ
What kind of moth has eyes on its wings?
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Name:The moth is called the Polyphemus moth, named after the one-eyed giant from Greek mythology.
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Appearance:It’s a tan-colored moth with a wingspan of about 6 inches. The most striking feature is the large, purplish eyespots on its hindwings.
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Purpose of eyespots:The eyespots are thought to be a defense mechanism to confuse or deter predators.
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Distribution:Polyphemus moths are found in North America, including the United States and Canada.
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Other moths with eyespots:While the Polyphemus moth is the most well-known, other moths, such as the Io moth (Automeris io), also have prominent eyespots on their hindwings.
What kind of butterfly has eyes on its wings?
The squinting bush brown butterfly (Bicyclus anynana) features a series of eyespots along the outer edges of it wings. The patterns vary depending on the time of year.
Are polyphemus moths rare?
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Widespread Distribution:Polyphemus moths (Antheraea polyphemus) are found across much of North America, including Canada and the United States (except for Arizona and Nevada).
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Abundant in Various Habitats:They can be found in and near forests, parks, suburban areas, orchards, and wetlands.
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Not Usually in Need of Conservation:While their populations can be affected by habitat loss and other factors, they are not generally considered to be in need of conservation efforts.
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Two broods per yearTwo broods generally hatch each year throughout the United States, one in early spring and one in late summer.
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Easy to Raise in Captivity:Polyphemus moths are relatively easy to raise in captivity, making them a popular choice for hobbyists and nature enthusiasts.
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Caterpillar FoodCaterpillar foods include leaves of broad leaved trees and shrubs including birch, grape, hickory, maple, oak, willow, and species in the rose family.
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Habitat DestructionHabitat destruction, light pollution, and parasitic wasps do cut down on their population.
How to tell if it’s a moth or butterfly?
Butterflies have a slender and more streamlined body shape, while moths have a chunkier and more robust body shape, and their bodies are often covered in fine …Mar 14, 2023
Why do butterflies and moths have eye-like patterns on their wings?
Butterflies and moths with eye-like patterns on their wings are fascinating examples of nature’s ingenuity. These eye spots serve as a defense mechanism, tricking predators into thinking they are staring into the eyes of a much larger and more dangerous creature.
What are eyespots on butterflies and moths?
Eyespots on the wings of butterflies and moths are a type of wing decoration that resembles large mammal eyes. These eyespots can be full of dark circles with or without margins, and some even have a white central section.
When do butterflies and moths show their eyespots?
Butterflies and moths may also rely on eyespots as a surprise element to keep predators away. Many species only show their eyespots when the wings are fully open, typically when they see an approaching predator. Here are 26 common butterflies and moths with eyes on their wings and learn why they have eyespots (plus other animals with eyespots).
Do moths & butterflies have circular marks on their wings?
When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. Some moths and butterflies bear circular, high-contrast marks on their wings that have long been thought to scare off predators by mimicking the eyes of the predators’ own enemies.
Do butterflies have eyes on their wings?
Yes, numerous species of butterflies and moths have eyes on their wings. Some species are particularly known for having more than 2 eyespots.
Why are butterfly & moth wings so beautiful?
Butterfly and moth wings can be stunningly beautiful. More importantly, some have colourful and elaborate patterns that serve as a defence against hungry predators.