The Ulysses butterfly (Papilio ulysses), also known as the Blue Mountain Butterfly or the Blue Mountain Swallowtail, is a large swallowtail butterfly, endemic to Australasia. This butterfly is used as an emblem for Queensland tourism.
The male is an iridescent blue-green with black edges. The female is more subdued in color. The body is plump and dark with a blue-green sheen. The Ulysses Butterfly has a wingspan of about 5.5 inches (14 cm). Both have a long "swallowtail."
Males are attracted to most blue objects (mistaking them for females). There are 16 known subspecies of the Ulysses. It is a protected species in Queensland, Australia.
The Ulysses butterfly inhabits a portion of northeastern Australia (eastern Queensland) and is also found in other places alike; New Guinea, the Moluccas, Bismarck Archipelago and northwestern Solomon Islands. New Caledonia is instead inhabited by the similar relative, Papilio montrouzieri.
The Ulysses butterfly typically has a wingspan of about 14 cm (5.5 in), but depending on subspecies has some variations in size. The upperside of the wings are an iridescent electric blue; the underside is a more subdued black and brown. The colours are produced by the microscopic structure of the scales, a phenomenon called structural colouration.
The female of the species is different from the male in that she has little crescents of blue in the back, upside sections of her hind wings, where there is only black for males. When the butterfly is perched the intense blue of its wings is hidden by the plainer brown under side of its wings, helping it to blend in with its surroundings. When in flight, the butterfly can be seen hundreds of metres away as sudden bright blue flashes. Males are strongly attracted to the colour blue, including blue objects which are sometimes mistaken for females.
The Ulysses butterfly inhabits tropical rainforest areas and suburban gardens. It is protected by the Australian government, although the species is not endangered. In the past, this butterfly had been threatened but planting Pink Flowered Doughwood has increased its numbers. Reduction in the number of the Euodia trees, a tree heavily used for laying eggs and for leaves eaten by caterpillars, may threaten the survival of this butterfly. Females favour small trees up to 2 metres tall to lay their eggs.
Foods for this butterfly include: kerosene wood and a variety of citrus plants. In Australia, the Ulysses butterfly's food is the blossoms of the Pink Flowered Doughwood, a tree with clusters of small pink flowers that extrude from its branches.