Pied Currawong - Distribution and Habitat

Distribution and Habitat

The Pied Currawong is common in both wet and dry sclerophyll forests, rural and semi-urban environments throughout eastern Australia, from Cape York Peninsula to western Victoria and Lord Howe Island, where it occurs as an endemic subspecies. In general, the Pied Currawong is sedentary, although some populations from higher altitudes move to areas of lower elevation in winter. However, evidence for the extent of migration is conflicting, and the species' movements have been little studied to date. It has adapted well to European presence, and has become more common in many areas of eastern Australia, with surveys in Nanango, Queensland, Barham, New South Wales, Geelong, Victoria, as well as the Northern Tablelands and South West Slopes regions in New South Wales, all showing an increase in population. This increase has been most marked, however, in Sydney and Canberra since the 1940s and 1960s respectively. In both cities, the species had previously been a winter resident only, but now remains year-round and breeds there. They are a dominant species and common inhabitant of Sydney gardens. More recently still, a survey of the population of Pied Currawongs in southeastern Queensland between 1980 and 2000 had found the species had become more numerous there, including suburban Brisbane. One 1992 survey reported the total number of Pied Currawongs in Australia had doubled from 3 million birds in the 1960s to 6 million in the early 1990s.

The Pied Currawong is able to cross bodies of water of some size, as it has been recorded from Rodondo Island, which lies 10 km (6 mi) off the coast of Wilsons Promontory in Victoria, as well as some offshore islands in Queensland. It has disappeared from Tryon, North West, Masthead and Heron Islands in the Capricorn Group on the Great Barrier Reef. The presence of the Lord Howe subspecies is possibly the result of a chance landing there.

The Pied Currawong's impact on smaller birds that are vulnerable to nest predation is controversial: several studies have suggested that the species has become a serious problem, but the truth of this widely held perception was queried in a 2001 review of the published literature on their foraging habits by Bayly and Blumstein of Macquarie University, who observed that common introduced birds were more affected than native birds. However, predation by Pied Currawongs has been a factor in the decline of Gould's Petrel at a colony on Cabbage Tree Island, near Port Stephens in New South Wales; currawongs have been reported preying on adult seabirds. Their removal from the islands halted a decline of the threatened petrels. Furthermore, a University of New England study published in 2006 reported that the breeding success rates for the Eastern Yellow Robin (Eopsaltria australis) and Scarlet Robin (Petroica boodang) on the New England Tablelands were improved after nests were protected and currawongs culled, and some Yellow Robins even re-colonised an area where they had become locally extinct. The presence of Pied Currawongs in Sydney gardens is negatively correlated with the presence of Silvereyes (Zosterops lateralis).

The species has been implicated in the spread of weeds by consuming and dispersing fruit and seed. In the first half of the twentieth century, Pied Currawongs were shot as they were considered pests of corn and strawberry crops, as well as assisting in the spread of the prickly pear. They were also shot on Lord Howe Island for attacking chickens. However, they are seen as beneficial in forestry as they consume phasmids, and also in agriculture for eating cocoons of the codling moth.