Ornithoptera euphorion

The wingspan can be up to 15 cm (5.9 in) in females, and 12.5 cm (4.9 in) in males. A closely allied species, the New Guinea or Priam's birdwing (Ornithoptera priamus) reaches 19 cm (7.5 in) and is the largest butterfly species found in Australia, but it is not endemic. O. euphorion is quite closely related to O. richmondia, differing by its greater size and more extensive green markings in the male. Males have a predominantly black upper wing with emerald green flashes, however the female lacks the green colouring, having a plain black upper wing with white patches. The female is the larger of the two sexes. There was a spectacular and rare genetic mutation of this butterfly, where single aberrant female produced less than 40 aberrant progeny. The females were pale instead of dark, and the males were golden instead of green.

Cairns birdwings are found southwards from Mount Webb and Cooktown to Mackay in Queensland. Its favoured habitat is rainforest of the Queensland wet tropics region, including riverine forest, and particularly near the coast. It is also often seen in Cairns, attracted to the flowers of Lantana, Hibiscus and Bougainvillea in suburban gardens. The species is abundant throughout its range and is not threatened.