Poison Garden: Rajah Brooke's Birdwing

Today I have a challenge for fellow Malaysians (apologies to the rest), take out your Identity Card and find this very butterfly you see below. This is her story and how she became Malaysia’s National butterfly. However, her existence is now threatened by very Malaysians.

Rajah Brooke's birdwing (Trogonoptera brookiana)

In 1855, the famous naturalist Wallace (who co-conceived the theory of evolution as Charles Darwin) discovered this large butterfly with jet black wings and iridescent green scales in Borneo. He named it after James Brooke, who was the ruler of Sarawak. The Rajah Brooke’s birdwing would become so famous and iconic, it was collected and sold all over the world, until it became an endangered species. To protect it from extinction, the Rajah Brooke was crowned the National Butterfly of Malaysia. Just so you know, the colours of the butterfly’s wings aren’t caused by pigments, but rather microscopic scales with tiny ridges, much like the surface of a CD. When light waves hit these ridges, they split into individual waves that travel at different speeds. Some light waves (colours) cancel out each other, while others get amplified. It is the greatly amplified light waves that our eyes perceive as iridescence. 

 

In Nature, the Rajah Brooke’s birdwing isn’t as defenseless as it seems. In fact, it is protected by a poison that it gained through aeons of evolution. The Rajah Brooke is closely related to the common rose butterfly, and its caterpillars only feed on birthworts (Aristolochia), which are deadly poisonous to most animals. The toxin, called aristolochic acid can permanently damage  DNA, but the Rajah Brooke is immune because its body cannot convert aristolochic acid into its deadly form. Instead, Rajah Brooke feeds exclusively on Aristolochia to accumulate aristolochic acid right into its adulthood. The bright colouration you see on the Rajah Brooke’s wings is actually a warning for poison. This is a powerful survival strategy because when one can eat something others can’t, it’s a great advantage. However, it also means that the Rajah Brooke’s survival is tightly bound to the birthworts.

 

Today, 165 years later, how many of us still remember the story of Rajah Brooke, let alone care about its survival? What’s more ironic is that Malaysia's national flower is a Hibiscus (you can also find it beside the Rajah Brooke on your IC), which has nothing to do with Rajah Brooke. In fact, when the Rajah Brooke was first discovered, people only found the male specimens in abundance, and thought that the females were extremely rare. That’s because the female Rajah Brooke fly high above in the canopy, probably around Aristolochia, which are several species of climbers native to Malaysia. It’s only the males that tend to congregate on the ground, sipping minerals they need for reproduction. If anything, there’s still a whole world out there waiting to be discovered! Recently, more and more scientists think that there are many subspecies of Rajah Brooke, confined only to patches of forests in Malaysia and Southeast Asia. The life-cycle and biology of Malaysia's National butterfly are just as inspiring and delicate as its wings. Wouldn’t it be sad if we keep them behind glass doors, or perhaps a picture is all that’s left for future Malaysians to see. Who knows, the last of birthworts may become extinct with on-going deforestation, pollution, or climate change. 

 

In this period of contagion and uncertainty, let’s take some time to slow down, and look at things that we might have overlooked in the past. There are great wonders and meanings to be discovered and shared in this One Planet, or perhaps one Nation, that we shall pass on to our future generations.