26 February 2011

Butterfly of the Month - February 2011

Butterfly of the Month - February 2011
The Purple Duke (Eulaceura osteria kumana)

The short month of February is almost coming to an end, and the rainy weather that kept many a butterfly photographer in Singapore cooped up at home is also changing for sunny humid days. It will be butterfly season again soon, and members of ButterflyCircle started the year with great excitement, recording two new species to the Singapore Checklist - the Malay Dartlet and the White Banded Flat, and just as this article is being prepared, at least 2 other species have been observed!

Singapore, the Little Red Dot at the end of the Malay Peninsula, is thus far blessed with protection from natural disasters like earthquakes and typhoons. Even the 2004 tsunami, considered the deadliest tsunami in history, spared Singapore because of its location where it was shielded by Sumatra and Malaysia. The deadly tsunami, which was triggered by a 9.0 Richter scale quake which had its epicentre in the Indian Ocean near the west coast of Sumatra, killed at least 150,000 people across 11 countries and made millions homeless. And yet, Singapore was spared from the killer waves, despite its proximity to Sumatra.

The month of February, which is also the month in which I was born in 1959, is usually associated with the gemstone Amethyst. This gemstone is a purple-violet variety of quartz and ancient civilisations believed that the stone protected its owner from drunkenness! They were also believed to heal people and keep them cool-headed. Amethyst is usually associated with the colour purple and is the birthstone for the month of February.

The February born shall find,
Sincerity and peace of mind,
Freedom from passion and from care,
If they, the amethyst will wear.
- Gregorian Birthstone Poems

A male Purple Duke perches on the underside of a leaf

This month, we feature a Singapore butterfly with purple in its common name - the Purple Duke (Eulaceura osteria kumana). This species belongs to the subfamily Apaturinae, of which there are only two species found in Singapore. It is the sole representative of its genus in Singapore.

A male Purple Duke sunbathes with its wings opened flat

The male is pale purple brown above with a white discal band increasing in width from the forewing to mid-tornal area of the hindwing. The underside is tinged bluish-violet in a side light, and features ocelli in the sub-tornal area of both wings. The female is dull ochreous brown with obscure white markings on both wings. In flight the female resembles one of the females of the Euthalia or Tanaecia species.

A female Purple Duke shows the upperside of its wings as it sunbathes

The Purple Duke is a forest-dependent butterfly, and is not found outside the nature reserves of Singapore. It prefers shaded habitats in the forest understorey, and rarely leaves the safety of the forests.

The Purple Duke's typical perched pose, on the underside of a leaf. Note that the violet-blue sheen on the wings is sometimes more obvious when light from the flash hits the wings at a certain angles

The butterfly can be seasonally common, where up to half a dozen or more individuals can be seen flying around low shrubbery amongst shaded forest paths. It has a rapid flight and zips from perch to perch quickly. Both sexes of the Purple Duke have a unique habit of flying rapidly from its perch and settles on the undersides of leaves. If disturbed, it will take off and zips under another leaf to hide.

There are occasions, however, that the butterfly perches on the uppersides of leaves and occasionally open its wings flat to sunbathe, especially in the cool morning hours when the sun is just beginning to warm up the environment.

A newly-eclosed female Purple Duke opens her wings to sunbathe amongst low shrubbery

The Purple Duke's caterpillar host plant is a common forest plant, Gironniera nervosa, which is shares with another butterfly species, the Grey Sailor. The early stages of the Purple Duke has been recorded in Singapore and can be found on an earlier blog article here.

A female Purple Duke feeds on the ripened fruits of the Singapore Rhododendron

And so we end this 28-day February in the year 2011 as we look forward to the remaining months of the year with exciting new butterfly discoveries for Singapore!

Text by Khew SK : Photos by Sunny Chir, Chng CK, Federick Ho, Khew SK, Loke PF, Nelson Ong, Johnny Wee & Wong CM