Orthetrum caledonicum, the blue skimmer, is a common Australian dragonfly. Males have a powder blue thorax and abdomen pruinescent blue when mature. The females are brownish grey in colour while the teneral are yellow with black markings. They are medium in size, with a body length of 4.5 cm (2 in) and a wingspan of 7 cm (3 in). The species is widespread throughout mainland Australia and extending to Tasmania. It is also found in New Guinea, New Caledonia, Loyalty Islands and Lesser Sunda Islands. It inhabits a range of still and flowing water habitats including temporary waters.