I was strolling down the forest track in Eaglenest Wildlife Sanctuary. A wonderful protected area in West Kameng district of Arunachal Pradesh, Eaglenest is one of India’s best known birdwatching destinations. But my preference for this biodiversity haven is not just for its birds, but also for its butterflies, moths, amphibians and reptiles. Every trip that I have made to Eaglenest has thrown up some surprises. On this particular visit, I was surveying the area’s butterflies. It was a bright sunny day — a rarity in Eaglenest, where a cloudy day is par for the course most seasons.
My saunter down the forest track was broken by the briefest of glimpses of a brown and blue butterfly that flew past me. It must have been a blue crow butterfly, I muttered to myself. As the butterfly wafted past me, it flew into a nearby tree and promptly disappeared from sight! I was intrigued. If it indeed was the blue crow, then it had magically camouflaged itself.
I moved closer to the tree and searched for the butterfly, but I could not find it. Puzzled, I continued to stand near the tree when the blue ‘butterfly’ again flew past me. This time, I ran after it keeping a close eye on the insect.
When it settled some distance away, I noted carefully where it sat. This time, I knew the precise location of the insect. As I got close, I realised that I had been fooled. The insect I was watching was not a butterfly at all. It was a moth, mimicking a butterfly!
The moth, a Burnet moth (Amesia Sanguiflua), belongs to a family of moths called Zygaenidae. The moth had lovely blue wings, which made me mistake it for a blue crow. However, when the moth sat down, it folded its forewings over its blue hind wings. Its brown colour camouflaged it really well on the tree’s branches!
Burnet moths are bitter tasting to predators and hence avoided by them. This day flying burnet moth, not satisfied with the bitter-tasting strategy, also decided to copy a butterfly, and the bitter tasting blue crow butterfly at that.
As the images alongside show, the burnet moth (the mimic), bears a markedly good resemblance to the blue crow butterfly (the model) in colouration and patterns.
In addition, as the moth demonstrated, it copies the blue crow perfectly in flight! This provides the day flying moth additional protection from its predators.
Many butterflies and moths mimic other butterflies and moths to increase their chances of survival.
The butterfly or moth being copied is called the model, while the insect doing the copying is the mimic.
In fact, not all models are butterflies or moths. Some moths mimic wasps and even spiders!
Isn’t the natural world truly amazing?
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