Ornithoptera alexandrae

Queen Alexandra's Birdwing
male
female
Conservation status
Endangered (IUCN 2.3)
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Lepidoptera
Family:	Papilionidae
Genus:	Ornithoptera
Subgenus:	Straatmana Deslisle, 2007
Species:	O. alexandrae
Binomial name
Ornithoptera alexandrae Rothschild, 1907

Queen Alexandra's Birdwing (Ornithoptera alexandrae) is the largest butterfly in the world.

The species was named by Lord Walter Rothschild in 1907, in honour of Queen Alexandra, wife of King Edward VII of the United Kingdom. The first European to discover the species was Albert Stewart Meek in 1906, a collector employed by Lord Walter Rothschild to collect natural history specimens from Papua New Guinea. Although the first specimen was taken with the aid of a small shotgun, Meek soon discovered the early stages and bred out most of the first specimens. It is restricted to the forests of Oro Province in eastern Papua New Guinea.

Though most authorities now classify this species in the genus Ornithoptera, it has formerly been placed in the genus Troides or Aethoptera. In 2001 the lepidopterist Gilles Deslisle proposed placing it in its own subgenus (which some writers have treated as a genus); he originally proposed the name Zeunera, but this is a junior homonym (with Zeunera Piton 1936 [Orthoptera]), and his replacement is Straatmana.^[1]

Description

Female Queen Alexandra's Birdwings are larger than males with markedly rounder, broader wings. The female can reach a wingspan of 31 cm (12.2 inches), a body length of 8 cm (3.2 inches) and a body mass of up to 12 grams (0.42 oz), all enormous measurements for a butterfly. The female has brown wings with white markings and a cream-coloured body with a small section of red fur on its thorax. Males are smaller than females with brown wings that have iridescent blue and green markings and a bright yellow abdomen. The wingspan of the males is approximately 20 cm, but more usually about 16 cm. A spectacular form of the male is form atavus, which has gold spots on the hind wings^[2].

Host plants

Larvae of this species feed on the shell from which they hatched and then start to extract nutrients from pipe vines of the genus Pararistolochia (family Aristolochiaceae), including P. dielsiana and P. schlecteri. They feed initially on fresh foliage of the hostplants and their own eggs, ultimately ringbark the vine before pupating. Plants of the Aristolochiaceae family contain aristoloic acids in their leaves and stems. This is believed to be a potent vertebrate poison and is accumulated by larvae during their development. Adults feed at flowers providing a broad platform for the adults to land on, including Hibiscus.

Biology

Mounted specimens

The female Queen Alexandra’s Birdwing lays about 27 eggs during its entire lifespan; this estimate was made by Ray Straatman by dissecting adult females. Newly emerged larvae eat their own eggshells before feeding on fresh foliage. The larva is black with red tubercles and has a cream-colored band or saddle in the middle of its body. The larvae always ringbark the host vine before moving onto adjacent leaves or vines to become a pupa, which is golden yellow or tan in colour with black markings. Male pupae may be distinguished by a faint charcoal patch on the wing cases; this becomes a band of special scales in the adult butterfly called a sex brand. The time taken for this species to develop from egg to pupa is approximately six weeks, with the pupal stage taking a month or more. Adults emerge from the pupae early in the morning while humidity is still high, as the enormous wings may dry out before they have fully expanded if the humidity drops. The adults may live for three months or more and have few predators, excluding large Orb Weaving spiders (Nephila spp.) and some small birds.

The adults are powerful fliers most active in the early morning and again at dusk when they actively feed at flowers. Males also patrol areas of the host plants for newly emerged females early in the morning. Females may be seen searching for host plants for most of the day. Courtship is brief but spectacular; males hover above a potential mate, dousing her with a pheromone to induce mating. Receptive females will allow the male to land and pair, while unreceptive females will fly off or otherwise discourage mating. Males are strongly territorial and will see off potential rivals, sometimes chasing small birds as well as other birdwing species. Flight is usually high in the rainforest canopy, but both sexes descend to within a few meters of the ground while feeding or laying blue eggs.

Threats

The Queen Alexandra’s Birdwing is considered endangered by the IUCN,^[3] being restricted to approximately 100 square kilometres of coastal rainforest near Popondetta, Oro Province, Papua New Guinea. It is nonetheless abundant locally and requires old growth rainforest for its long term survival. The major threat for this species is habitat destruction for oil palm plantations. However, it must be noted that the eruption of nearby Mount Lamington in the 1950s destroyed a very large area of this species' former habitat and is a key reason for its current rarity. Because of its rarity, this butterfly fetches a very high price on the black market.

The species is also highly prized by collectors, with illegally traded specimens selling for thousands of dollars. Although collectors are often implicated with the decline of this species, habitat destruction is the main threat. Early collectors, frustrated by the height at which adults fly during the day, often used small shotguns to down specimens, but because collectors demand high quality specimens for their collections, most specimens are reared from larvae or pupae.

The species is listed on Appendix I of CITES, meaning that international trade is illegal. At the 2006 meeting of the CITES Animals Committee some suggested it should be moved to Appendix II (which would allow restricted trade in the species), as the conservation benefits of sustainable management perhaps are higher than those of the trade ban.^[4]

References

1. ^ Deslisle, G. (2007) "Straatmana : a remplacement name for the subgenus Zeunera Deslisle 2001 (Lep. Papilionidae)" Lambillionea (Brussels) N° 2 vol 1 & 2, June 2007, p. 238
2. ^ "Endangered Species - Queen Alexandra's Birdwing Butterfly Facts". http://www.earthsendangered.com/profile.asp?view=all&ID=4&sp=52. Retrieved 2009-02-17. 
3. ^ Gimenez Dixon (1996). Ornithoptera alexandrae. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 11 May 2006. Listed as Endangered (EN B1+2c v2.3)
4. ^ CITES (2006). Earth Negotiations Bulletin. Summary of the 22nd Meeting of the CITES Animals Committee.

External links

• www.butterflycorner.net (English/German)
• Entry at Nagypal.net
• Enchanted Learning - Queen Alexandra's Birdwing