Alexandra Hospital's winged beauties

Matthew Phan, Business Times 8 Apr 08;

IT'S a magical place where photographers gather at weekends to snap some of Singapore's rarest and most beautiful creatures.

The butterfly trail at Alexandra Hospital is Singapore's biggest open-concept butterfly garden, with more than 100 different species sighted. They include the Common Birdwing, a bright yellow and black butterfly with a wingspan of over 15 cm, which the hospital has contributed to the Istana and the Botanic Gardens.

Unlike at Sentosa there are no nets at Alexandra Hospital to keep the butterflies in - they are free to come and go as they wish.

The trick to keeping them around, says caretaker Rosalind Tan, who was chief occupational therapist at the hospital before she retired two years ago, is to grow the right plants.

The Common Birdwing, for example, may have arrived from Malaysia, flitting from green space to green space until it found the gardens from their scent, she says.

Alexandra Hospital's gardens, which collectively stretch over the size of two football fields, have at least 500 species of trees and shrubs, including some 200 butterfly shrubs. The latter are fruit trees or flowering plants that mature butterflies obtain nectar from and hosts where they lay eggs.

Each species of butterfly may feed from several plants, but its caterpillar will eat only one particular host plant, says Ms Tan. Many of these are common fruit trees such as mango, guava or banana, but there are also several weeds, such as the common snakeweed, tyler flora and stinking passion flower.

'You couldn't buy them from a nursery if you wanted to,' says Ms Tan, who obtained plant samples from the forest or from friends and cultivated them in her own garden before transplanting them in the hospital grounds.

Other plants are brought by birds, such as the mistletoe, which grows on trees but not on the ground. It hosts the Painted Jezebel, a pretty white-yellow-and-red winged butterfly that 'just appeared', she says.

Alexandra Hospital started the garden in 2002 when it decided to plant shrubs along a big drain at the edge of the hospital grounds, a 'no man's land' at the time.

Today, caterpillar host plants are grown near the drain so patients do not see them, while the flowering plants are kept nearer the hospital so butterflies flit to the peopled areas.

Ms Tan is also working with conservation biologist Ho Hua Chew to design wetlands and grasslands at the back of the hospital, to attract birds. Some 60-plus bird species have already been sighted and she is aiming for more than 100.

But her consultants on the butterfly garden were simply amateur enthusiasts, such as the Butterfly Circle, and books, she says.