This article was originally published by Mongabay and is republished with permission.
A private sector initiative is setting up urban butterfly gardens in Sri Lanka, creating butterfly sanctuaries.
The creator of the urban butterfly habitats is proposing the replication of his conservation model to support the survival of butterfly populations.
Though there is high endemism, Sri Lanka’s butterflies are threatened by multiple causes including habitat loss, deforestation, climate change and increase in alien species.
Take a lifelong love for conservation, pair it with the right support group, and what do you get? An urban butterfly garden.
A naturalist and author of several books on wildlife, Rajika Gamage’s biggest passion is to contribute to species conservation, both fauna and flora. But butterflies always have set his heart aflutter.
A decade ago, he attempted to set up an urban butterfly garden with the support of a global conservation body. But it bore no fruit. He was surprised, therefore, when the private company behind the globally famous tea brand Dilmah offered support to help him set up an urban butterfly sanctuary, a concept he pioneered in Sri Lanka.
In 2011, together with Dilmah Conservation, Gamage created an urban butterfly park on the site of what was once a garbage dump for a clothing company.
Rajika Gamage, the creator of the urban butterfly garden, sharing the ‘butterfly experience’ with young visitors. Photo courtesy of Rajika Gamage/Dilmah Conservation
While many conservationists doubted the viability of a butterfly garden in an urban setting, a determined Gamage worked with his team to convert some 660 square meters (7,080 square feet) of stinky marsh into a butterfly sanctuary. With six inches of new soil, the plot was soon landscaped to create the butterfly garden in Moratuwa, in southwestern Sri Lanka.
Here, even on the cloudiest day, more than 15 species of butterflies can be easily observed, with more than 60 species recorded since its opening in 2011.
Sri Lanka Blue Oak Leaf (Kallima philarchus) is a Nymphalid butterfly known for its spectacular shaded blue wings. With wings closed, it closely resembles a dry oak leaf.
The Sri Lanka Lesser Albatross (Appias galene) is a butterfly species endemic to the island.
“Butterflies are facing rapid extinction and need creative conservation methods,” Gamage says. “In Sri Lanka, there are butterfly houses with an indoor setup. We envisaged a conservation model with an open environment — without any form of species in captivity.”
He studied suitable host plants and nectar plants for creating a “walk-through” sanctuary, now extremely popular with children and researchers alike. Next, some 70 host plants and 20 nectar plants native to Sri Lanka were introduced to create the habitat. While some butterfly species have a single host plant, others have a few.
In choosing species, we eliminated those requiring special conditions for survival, such as forest habitats,” Gamage says. “In the very first month, we recorded five species [of butterflies], and within six months, about 12. Within the first one and a half years, we recorded over 50 species and significant butterfly populations.
Sri Lanka Tree Brown (Lethe daretis) is an endemic butterfly species restricted to cloud forests of Sri Lanka’s Central Highlands.
The butterfly presence eventually stabilized, with about 15 species a day, including seasonal migratory species. A few threatened species and more widespread ones, like the common tiger butterfly (Danaus genutia), are regularly sighted here. “It is now a sustainable ecosystem,” says Prasad Tharanga, arboretum coordinator at Dilmah Conservation. “It is important to maintain sufficient sunlight, plant height and the micro habitat for species survival.”
The garden, besides forming a natural habitat for the more common butterflies to reside in, offers a perfect setting for learning about the insects.
First described by John Westwood in 1848, the Sri Lanka Tree Nymph is endemic to Sri Lanka.
Gamage says butterflies are more important as an indicator species than as a pollinator. “Bees are better pollinators while butterflies are more important as an ‘indicative’ species. They are found in rich habitats with high levels of diversity, especially plants,” he says.
Sri Lanka has failed to recognize the importance of these species beyond their ornamental value, says Gamage.
The Crimson Rose (Pachliopta hector) is a large swallowtail butterfly.
With butterfly populations on the wane, Gamage says the rate of biodiversity loss needs to be addressed. “There is an increase in invasive plants, thus altering our plant diversity. Nectar is more difficult to find while changes in weather patterns are robbing us of marked wet seasons, when butterflies lay eggs.”
The Sri Lanka Birdwing is Sri Lanka’s national butterfly and the largest endemic butterfly, is found in large numbers in the Sinharaja Forest Reserve, while a majority of endemic butterfly species are found in the wet zone forests.
Troides darsius, the Sri Lanka Birdwing, is the largest butterfly recorded on the island. It is also the national butterfly of Sri Lanka.
Gamage offers two solutions for butterfly conservation, the first focused on urban environments. “Much of urban landscaping can be done with some uniformity, ensuring the maintenance of biodiversity. Before landscaping begins, ideally, an ecologist should work on it. We need a national approach to ensure minimum ecological balance in maintaining spaces like home gardens, work spaces and even road sides.”
The second solution: maintain butterfly conservation zones in every national park. “Visitors drive through these nature reserves to watch four-legged animals. Butterflies cannot be observed that way. We can create habitats at each national park for a walk-through butterfly experience.