When its wings are closed, the dead leaf butterfly looks exactly like a dried autumn leaf – probably the best camouflage a butterfly could ever want. But when those wings are open, a brilliant color pattern is revealed making it one of the world’s prettiest wings.
Image credit: Rahul K. Natu/TBC
Also known as the orange oakleaf butterfly (Kallima inachus), the dead leaf butterfly is found in Tropical Asia, from India to Japan, but mostly in South East Asia, including in Vietnam, Laos, Taiwan, and Thailand.
When they are closed, the butterfly’s wings are shaped like a leaf. In this position, nothing but the cryptic underside markings are visible, making the animal look like a dried leaf. Even the veins are darkened to make it resemble the veins of a leaf, so the resemblance to a dried leaf is indeed extremely realistic.
When the wings are open, a black apex is exhibited along with an orange discal band and a deep blue base. Here’s what it all looks like in action:
But it doesn’t all end there, because this amazing little creature even changes its look with the seasons. Thanks to a phenomenon known as polyphenism, the dead leaf butterfly has separate dry-season and wet-season versions.
These season-induced alterations do not only differ in coloration – the wet-season form tends to be smaller than the dry-season form.
A wet-season ‘version’ on the left, and a dry-season ‘version’ on the right
Image credit: Rahul K. Natu/Wikimedia; Sumita Roy Dutta/Wikimedia
As for the other, colored, side of the wings: they also change with the seasons.
Below, you can see a wet-season example on the left, and a more muted, violet-toned dry-season form on the right.
Image credit: 岡部碩道/ Wikimedia; J.M.Garg/Wikimedia
The exact reason for the two existence of these distinct season-dependant forms remains a mystery. According to some scientists, it shows that the dead leaf butterfly – along with a number of similar tropical butterfly species – has managed to strike the perfect balance between hiding completely, and employing some neat anti-predator strategies.
Through the dry season, tropical butterflies tend to be less active so, as long as they stay perfectly still, they only need some camouflage to remain unspotted by predators. As the dead leaf comparison image above shows, the dry-season patterning is almost completely uniform, meaning the animal can stay completely hidden.
During the wet season, however, when they are more active, the dead leaf butterflies sport eyespot patterns to deter ants, birds, spiders, and wasps from trying to eat them.
The eyespot pattern is clearly visible here:
Finally, the footage below shows how the eye holes appear to ‘light up’ as the butterfly moves its wings: