Cairns Birdwing

The Cairns Birdwing (Ornithoptera euphorion) is Australia's largest endemic butterfly species, with females reaching a wingspan of up to 16 cm. Males are usually a few centimeters smaller. A closely allied species, the New Guinea or Priam's Birdwing (Ornithoptera priamus) reaches 19 cm and is the largest butterfly species found in Australia, but it is not endemic. Cairns Birdwings are found southwards from Mount Webb and Cooktown to Mackay in Queensland. Favoured habitat is primary rainforest, although the species will breed readily in a home garden if the correct larval host plants are grown.

Males have a predominately black upper wing with emerald green flashes, however the female lacks the green coloring, having a plain black upper wing with white patches. The female is the larger of the two sexes. The larvae or caterpillars of this species breed on several species of pipe vine, including Aristolochia tagala and Pararistolochia deltantha. The latter species is more commonly used at altitude, with A. tagala used at sea level.
The leaves of the introduced Dutchman's Pipe (Aristolochia elegans) will kill the larvae of this species and several other swallowtail butterflies in Australia. It should not be planted anywhere in Queensland, New South Wales or the Northern Territory. Adults are freely attracted to flowers, including Lantana, Hibiscus and Bougainvillea. The species is abundant throughout its range and is not threatened.