Birdwing butterflies - what are they?
The birdwing butterflies tend to be rare but spectacular butterflies. The name 'birdwing' comes from the Latin name Ornithoptera.
The butterflies live in rainforests around south-east Asia and Australia, where they soar above the forest canopy like birds.
There are about 10 species of birdwing butterfly. This includes the largest butterfly in the world, the Queen Alexandra, which can have a wing span of up to 30cm (12 inches).
What do they eat?
The birdwings feed on the nectar from flowers of the Pipe Vines, Aristolochia species.
These grow many metres above the forest floor. As a result, the butterflies rarely come to ground level.
Many species of birdwing feed on a particular species ofvine. This limits their distribution to where the right vines are found.
How do they live?
- The adult butterflies mate.
- Eggs are laid on the food plant.
- The caterpillar hatches and feeds.
- As it grows the caterpillar sheds its skin.
- Once big enough, the caterpillar stops feeding and pupates.
- After about 2 weeks the wonderful adult butterfly emerges…
Why are they in trouble?
Because of their size and great beauty, birdwings are highly prized by collectors. A single specimen of the Queen Alexandra can fetch thousands of dollars.
However the biggest threat to the butterflies is from habitat destruction. Logging activity and palm oil plantations erode away the remaining rainforest habitat.
Why should we care?
Birdwings are an important part of their habitat:
- They are food for other animals.
- They are pollinators of plants.
- They can be an important form of income for local people through schemes such as 'butterfly ranching'.
What can be done?
The best way we can protect birdwing butterflies is to preserve their habitat.
This way the many thousands of unique plants and animals that also live with the butterflies will be protected.
Butterfly ranching - Helping to conserve the birdwing butterfly
Papua New Guinea is part of New Guinea - a large island in the South West Pacific Ocean. Much of the Island is covered in virgin rainforest, and this is home to many species of birdwing butterfly. The government of Papua New Guinea has a unique section to its wildlife law - it is the only country whose constitution designates insects as a renewable natural resource.
During the 1960s there was an escalation in the international trade of butterflies. This was having an effect on wild populations (although habitat loss was, and still is, a much greater threat). For Papua New Guinea it was also a loss of potential income, as all the profit went to foreign dealers.
To control the butterfly trade in Papua New Guinea a number of events occurred:
- Birdwing butterflies were legally protected to restrict the commercial collection of wild populations.
- The Insect Farming and Trading Agency (IFTA) was set up to monitor and control the insect trade.
To provide income for local people, and to protect wild populations, the IFTA set up 'butterfly ranching' schemes. This is done by providing interested villages with the food vines of birdwing butterflies, on which wild butterflies lay their eggs. The caterpillars then feed on the vines until they pupate. The pupa are collected and placed in protected hatching cages. Once reared the adult butterflies are then sold to collectors and artists.
This process of rearing butterflies:
- Protects the wild populations and their habitat
- Promotes an understanding of butterfly biology
- Brings income to local farmers.
The balance between conservation and economics is very tricky - too many butterflies and the prices drop!
However butterfly ranching in Papua New Guinea has been a successful, but small scale, project. The buying of 'ranched' or 'farmed' butterflies is helping to protect the wild populations of birdwing butterflies and their habitat.
The birdwing butterfly illustrations used here are from The Icones Ornithopterorum by the naturalist R. H. F. Rippon, whose entomological and molluscan collections are housed here at Amgueddfa Cymru - National Museum Wales.
Article Date: 23 July 2007