“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.”
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.
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.
While Sri Lanka has failed to recognize the importance of these species beyond their ornamental value, other countries hold patents for endemic butterflies, such as the crimson rose (Pachliopta hector), says Gamage.
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 Ceylon rose (Pachliopta jophon) and Ceylon birdwing (Troides darsius) are presently included in the appendices of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).
The Ceylon birdwing, 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.
This story first appeared on Mongabay
South Africa Today – Environment
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