Queen Alexandra’s birdwing  (Ornithoptera alexandrae)

Classified as Endangered (EN) on the IUCN Red List (1) and listed on Appendix I of CITES (3).

With an enormous wingspan of up to 28 centimetres, Queen Alexandra’s birdwing is the world’s largest butterfly. Vibrantly coloured, this magnificent butterfly displays marked sexual dimorphism (2) (4). The attractive male has blue-green iridescent streaks across the largely black wings, with a scattering of contrasting yellow spots. The larger female is somewhat duller, with a brown colour across the wings and yellow blotches on the tips. On both sexes, the head and thorax is black and the abdomen is a striking yellow (2). Like the adult, the caterpillar of Queen Alexandra’s birdwing is conspicuously coloured, with a dark, wine-red body, numerous contrasting bright red spines, and two large, yellow central spines. During metamorphosis, this butterfly forms a light brown, ground-coloured chrysalis (5).

Endemic to northern Papua New Guinea, east of the Owen Stanley Mountains, Queen Alexandra’s birdwing has an extremely small range (6).

Queen Alexandra’s birdwing is found in the lowland rainforests of Papua New Guinea, up to 900 metres above sea level (5) (6).

A monophagous species, Queen Alexandra’s birdwing feeds only from the vine species Aristolochia schlechteri. This vine also plays a central role in reproduction, as the butterfly lays a single egg on the underside of one of the leaves. After some 11 to 13 days the caterpillar hatches and eats almost constantly, rapidly increasing in size (5). The vine contains a toxic substance which, although not poisonous to the caterpillar, makes the caterpillar distasteful to potential predators. This trait is advertised by the caterpillar’s bright, conspicuous colouration, but if consumed by a naive predator, the toxin may cause severe vomiting (6). The caterpillar’s rapid growth is accompanied by six moults, in which the caterpillar grows new skin and sheds the former, before forming a chrysalis, in which metamorphosis takes place over a period of some 40 to 45 days. Once emerged, the adult butterfly remains dependant upon the same vine, feeding from its flowers with an elongated proboscis (5).

As one of the world’s most beautiful butterflies, Queen Alexandra’s birdwing is extremely attractive to collectors. Fetching thousands of dollars per butterfly, this rare species has suffered severely from over harvesting (4). Recognising a dramatic decline, in 1966 the Papua New Guinea government gave Queen Alexandra’s birdwing legal protection from collectors. Consequently, trade in this butterfly has been somewhat reduced, but illegal collection continues to threaten this species. Today however, the greatest threat to Queen Alexandra’s birdwing is the loss of its lowland rainforest habitat. Historically, forests were cleared for subsistence farming and logging, and large tracts of forest were destroyed by the volcanic eruption of Mount Lamington in 1951. Presently, the main cause behind forest loss is the expansion of the palm oil industry, compounded by the development of rubber and cocoa plantations (7).  

Threatened by illegal trade and habitat loss, the survival of Queen Alexandra’s birdwing is dependant upon the successful implementation of conservation measures. To abate trade pressure, Queen Alexandra’s birdwing is listed on Appendix I of the Convention on International Trade in Endangered Species (CITES), and as an Annex A species in the EU Council Regulation on trade of wild species, both of which prohibit international trade (2) (3). Furthermore, the Papua New Guinea government has provided financial aid to local communities to develop butterfly nurseries.  These licensed farms aim to sustainably trade wild butterflies, whilst providing local communities with an additional income and improving the long-term survival prospects of many rare butterfly species (8). In addition, a large wildlife management area has been created, protecting much Queen Alexandra’s birdwing habitat. Assuming these measures continue successfully, there is significant hope that the beautiful Queen Alexandra’s birdwing will continue to grace the forests of Papua New Guinea (7). 

View information on this species at the UNEP World Conservation Monitoring Centre.

For more information on Queen Alexandra’s birdwing, see: 

• The American Museum of Natural History: 
  http://www.amnh.org/sciencebulletins/biobulletin/biobulletin/story823.html