North Queensland Naturalist
North Queensland Naturalist 53: 22-68
Distribution and decline of the Golden-shouldered Parrot Psephotellus chrysopterygius 1845–1990
Gabriel M. Crowley and Stephen T. Garnett
The Golden-shouldered Parrot (GSP) Psephotellus chrysopterygius (Gould, 1857) is a distinctive threatened species that is endemic to Cape York Peninsula (CYP), and a totem for First Nations Peoples. Its distribution has contracted since European occupation. We trawl the literature and public and private archives to provide a definitive set of historical records for the period 1845 to 1990 to help establish the species' former distribution and pattern of decline, and to compare these with the progression of pastoralism across the peninsula. We assessed the positional accuracy and veracity of all records, and consolidated records that had been replicated in multiple sources. We eliminated records from outside CYP; with a positional uncertainty of more than 15 km; or with errors that could not be corrected. This filtering process rejected 42% of records from BirdLife Australia, 62% of WildNet records and 37% of records from Atlas of Living Australia, and identified numerous others as duplicates, even though they had sometimes been allocated widely different coordinates. Hence, we advise close scrutiny of each individual record used for mapping and modelling species’ distributions.
The GSP’s distribution has been obscured by confusion between the three antbed-nesting parrot species; difficulty in differentiating GSP eggs from those of Varied Lorikeets; the anecdotal nature of most records; and attempts to massage qualitative locational information into a spatially-robust format. Addressing these issues, we accepted 212 unique GSP records from 103 locations. Of these, 9.4% were verified with specimens, 64.2% were highly reliable, and 67.3% were accurate to 1 km or better.
Until the early 20th century, GSPs were abundant across CYP, breeding wherever grassland or open tea tree woodland contained suitable magnetic or conical antbeds for nesting, including across extensive alluvial and coastal plains. Nesting progressively contracted to the flat edges and seepage area in hills, where conical antbeds predominate. This decline followed the displacement of First Nations Peoples and the establishment of the cattle industry, and the resultant loss of food plants, vegetation thickening and deterioration of the magnetic antbeds. The birds disappeared within 20–70 years of property development, remaining only in areas with access to rocky country with a lower level of disturbance (particularly grazing pressure), in which the birds can most easily find food in the early wet season. Recovery will depend on excluding cattle grazing from the remnant areas of the species' distribution – or carefully managing grazing pressure where this cannot be achieved – along with feral animal control, and fire management to control woodland invasion of open vegetation. First Nations Peoples are the original custodians of the parrot and its habitat, shared their knowledge about them with the first scientific collectors, and will be essential to the species’ recovery.