The ephemeral beauty of Himalayan butterflies

A fleeting inspiration is the thought that comes to mind as one watches butterflies flitting from one flower to the next, pausing to soak in the sun every once in a while, but taking off at the slightest hint of approach from the curious onlooker. Drifting on gossamer wings, in every flutter lies a story of transformation, from a humble caterpillar trudging slowly across the terra firma to a soaring specimen of ethereal beauty.

Butterflies are among the most charismatic and ecologically vital insects. Beyond their physical beauty, they are an indispensable part of the ecosystems they inhabit. As pollinators, they sustain plant reproduction and genetic diversity. Their larvae help regulate plant communities by feeding on them, while adults and caterpillars often serve as food for birds, spiders and other predators. While there are some species that undertake local or even large-distance migrations, most are sedentary, with specific habitat and climatic requirements, susceptible to the slightest of changes, due to which they serve as an important indicator of ecosystem health and climate impacts.

Out of the 1,500-odd species of butterflies recorded in the Indian mainland, nearly 67 per cent are known from the Indian Himalayan region. Such diversity is directly linked to the region’s remarkable topographical variations, which create numerous microhabitats across different elevational gradients.

Take the One-spot Grass Yellow (Eurema andersonii), which can adapt to altitudes ranging from the sea level to above 1,500 metres, or the Indian Tortoiseshell (Aglais caschmirensis) and the Dark Clouded Yellow (Colias fieldii), which can survive the extreme cold at altitudes above 3,000 metres.

The colours and patterns are by design as well. The Blue Pansy’s (Junonia orithya) bright blue upper wings with prominent eyespots are designed to ward off potential predators, while the underwings of the India Red Admiral (Vanessa Indica) mimic dead leaves for camouflage. The iridescent blue patches and light-refracting wing scales of the Paris Peacock (Papilio Paris) camouflage it against lichen-covered trees, while the Common Windmill emanates a foul smell combined with its bright colours, as a warning.

Then, there are the remarkable adaptations. Several high-altitude species like the Dark Clouded Yellow often display darker wing colouration to absorb more heat and use polarised light to navigate and locate nectar-rich flowers in overcast conditions. To avoid predation, species like the Common Windmill sequester toxins from their larval host plants, rendering both caterpillars and adults unpalatable to most predators.

Climate change poses the biggest existential threat to many Himalayan butterfly species, particularly those with narrow ecological niches as well as preference for specific host plants and microclimates. Rising temperatures force species to move higher in elevation. The Paris Peacock, once common at moderate elevations, is increasingly being restricted to higher altitudes as warming temperatures alter the distribution of its host plants. While some species can afford to migrate, those already at their highest possible elevations have nowhere to go.

Other anthropogenic activities leading to habitat degradation and fragmentation like agriculture and infrastructure expansion also contribute to population decline. The Common Windmill, dependent on forest corridors for migration, struggles when these pathways are disrupted, with isolated populations facing increased vulnerability to disease and reduced genetic diversity.

Forest fires can decimate caterpillars and pupae of species like the Chocolate Pansy (Junonia iphita), whose breeding season coincides with the period of the highest fire risk and the larvae inhabit low shrubs. Species like the One-spot Grass Yellow, whose larval stages develop in proximity to cultivated fields, suffer from pesticide use, while chemical runoff into water sources and hydropower projects that dry up wetlands affect those that congregate in marshy areas to extract minerals from the mud, like the Indian Tortoiseshell.

While the decline of charismatic megafauna and avifauna draws global attention, the silent disappearance of butterflies largely escapes public notice. These delicate creatures, despite being among our most sensitive ecological indicators, vanish without the outrage that accompanies the loss of larger species. Butterflies respond rapidly to subtle environmental shifts, with their complex lifecycles dependent on specific plant relationships, narrow temperature ranges, and precise seasonal timing. Their populations can collapse years before more resilient organisms start to show stress, making them nature’s early warning system for ecosystem degradation.

Butterflies spend most of their life in obscurity, going through the stages of egg, caterpillar and chrysalis, where they devour, grow and metamorphose before emerging as winged adults that live only for a few days or weeks. This fleeting adult phase, in which they dispense their worldly functions like mating and pollinating, embodies the ephemeral nature of life. Yet, we must not take this transience for granted, for even the smallest beings hold the threads of our planet’s ecological tapestry — threads we must protect before they unravel beyond repair.

— The writer is a climate expert and outdoor enthusiast

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