Butterfly migration fading away

By Ifham Nizam 

Sri Lanka has long been a land of unparalleled natural beauty, blessed with a rich biodiversity that has inspired poets, scientists, and conservationists alike.

Among its many wonders, one phenomenon stood out for its delicate charm and ecological significance: the annual butterfly migration.

For centuries, this breathtaking event marked the pilgrimage season to Sri Pada as thousands of white and yellow butterflies gracefully traversed the central highlands.

However, what was once a symbol of natural harmony has now become a fading memory.

Environmental researcher Rajika Gamage has spent years studying this migration, and his findings reveal a troubling picture. The decline of this spectacular event signals an urgent crisis—a warning about the state of Sri Lanka’s ecosystems and, ultimately, humanity’s role in their degradation.

Butterfly Migration:

An Ecological Masterpiece

The butterfly migration was more than a cultural marvel; it was a vital ecological process. From December to May, butterflies from the Pieridae family migrated between Sri Lanka’s northern and southern dry zones. While locals believed the butterflies were heading to worship at Sri Pada, science has since revealed the migration’s true purpose: a search for food, suitable host plants for larvae, and favourable environmental conditions.

Gamage describes the migration as a “bridge of life,” connecting regions and maintaining ecological balance. Butterflies are not just pretty creatures; they are keystone species, critical to the survival of ecosystems. Their migration played an essential role in pollinating plants, sustaining food webs, and ensuring biodiversity.

Role of Host Plants

A key driver of butterfly migration is the availability of host plants, which are crucial for laying eggs and nurturing larvae. Each butterfly species depends on specific host plants. For instance, butterflies in the Pieridae family rely on plants from the Capparaceae family, such as wild mustard.

“The relationship between butterflies and their host plants is symbiotic and delicate,” explains Gamage. “Without these plants, butterflies cannot reproduce, and their populations decline. The seasonal rains, often referred to locally as ‘Beli Thora Wessa,’ once supported the growth of these plants. Today, invasive species and habitat destruction have drastically reduced their availability.”

Invasion of Guinea Grass

Among the most significant threats to butterfly populations is Panicum maximum, commonly known as Guinea Grass. Initially introduced as livestock fodder, this invasive species has spread aggressively across Sri Lanka’s landscapes, outcompeting native vegetation.

“Guinea Grass is a silent killer,” warns Gamage. “It blankets vast areas, suffocating the native host plants and nectar sources that butterflies and other pollinators depend on. Its rapid spread is not just a threat to butterflies but to the entire ecosystem.”

The dominance of Guinea Grass has had a cascading effect on biodiversity. Native plants that supported not only butterflies but also other insects, birds, and small mammals, have been displaced. This disruption in the food chain threatens the survival of multiple species, highlighting the interconnectedness of ecosystems.

Cascading Effects on Ecosystems

The decline of butterfly populations is not an isolated event; it has far-reaching consequences for ecosystems. Butterflies are crucial pollinators, and their larvae are a vital food source for birds, reptiles, and other predators.

“When butterflies disappear, it’s not just about losing a species—it’s about losing the balance of the entire ecosystem,” Gamage notes. Pollination by butterflies and bees directly influences the productivity of fruit trees and crops. As pollinator populations decline, so do agricultural yields, affecting food security.

This ecological imbalance extends to soil health and water cycles, further compounding the challenges of climate change. The disappearance of butterflies is a stark reminder that even small changes in ecosystems can have significant, long-term impacts.

Cultural and Historical Significance

The butterfly migration is not just an ecological event; it is deeply rooted in Sri Lanka’s culture and traditions. For centuries, people believed the butterflies were on a sacred journey to Sri Pada. This belief reinforced a spiritual connection to nature, inspiring reverence and conservation.

However, modern society has drifted away from these values. Rapid urbanization, industrial agriculture, and deforestation have eroded the natural habitats that once supported such migrations. The cultural loss is as profound as the ecological one, severing the bond between people and nature.

Signs of a Larger Crisis

The disappearance of butterfly migrations is symptomatic of a larger environmental crisis. Sri Lanka is witnessing a decline in biodiversity, with many native species of plants and animals under threat. The unchecked spread of invasive species, deforestation, and pollution are all contributing factors.

Gamage emphasizes, “The butterfly migration is a red flag—a warning about the state of our environment. If we continue down this path, we risk triggering a cascade of ecological collapses that will affect everything, from agriculture to water resources.”

Call for Urgent Action

Addressing this crisis requires immediate and sustained action. Gamage outlines several steps that can help reverse the decline of butterfly populations and restore ecological balance:

Control Invasive Species:

 Implement targeted programmes to remove Guinea Grass and other invasive plants. This will create space for native vegetation to thrive.

Restore Native Habitats: 

Reintroduce native host plants and nectar sources to areas affected by invasive species. This can be achieved through community-based reforestation projects.

Raise Awareness:

Educate the public about the importance of biodiversity and the role of butterflies in ecosystems. Community involvement is key to long-term conservation.

Enforce Environmental Policies:

Strengthen laws and regulations to protect natural habitats from deforestation and development.

Promote Sustainable Practices:

Encourage sustainable agriculture and land use practices that prioritize biodiversity.

Shared Responsibility

The responsibility for protecting Sri Lanka’s natural heritage lies with everyone—governments, communities, and individuals. Gamage points out, “Take a moment to reflect on the plants your grandparents relied on. Many of these, such as Gotukola, Polpala,

and Mukunuwenna, were readily available in home gardens. Today, they are becoming scarce. This is a clear indication of how far we have strayed from living in harmony with nature.”

He adds, “The solutions are within our reach, but they require a shift in mindset. We must value nature not just for its beauty but for its role in sustaining life.”

The Butterfly Effect

The decline of butterfly migrations is a sobering reminder of the fragility of ecosystems. It underscores the need for immediate action to preserve biodiversity and restore balance to our environment.

As Gamage aptly concludes, “We are at the brink of the sixth mass extinction. The disappearance of butterflies is not just nature’s tragedy—it’s humanity’s failure. But it’s not too late. By acting now, we can ensure a future where butterflies once again grace our skies, symbolizing hope and harmony.”

The silent vanishing of Sri Lanka’s butterfly migration is more than a loss of beauty; it is a call to action. It challenges us to rethink our relationship with nature and take responsibility for its preservation. In saving the butterflies, we may yet save ourselves.