Justification of Red List Category
Recent evidence strongly suggests that the population of this species is well over 10,000 individuals and although there are projected declines in nest hollows of 20-29% for one part of the population over the next three generations (19 years), there is not believed to be sufficient evidence of the link between hollow availability and parrot abundance such that the total population could be predicted to decline at a rate approaching 30% in the three generations. The species is consequently listed as Least Concern. If it is demonstrated that the loss of dead trees is likely to cause significant future declines in the global population, the status of this and other nest hollow-dependent species would warrant reconsideration.
An expert review panel considered it highly likely that the population in 2010 exceeded 10,000 mature individuals, probably by many thousands (Garnett et al. 2011). A study systematically sampling 23,000 km2 of parrot habitat on the western slopes in 2001 (Manning et al. 2007) found nearly 1,500 parrots in 53 out of 81 well-separated sites. Furthermore they were reported from throughout the landscape, not just where there were corridors of trees as had previously been thought essential for the species. A simple extrapolation of these results gives a total population of over 400,000 individuals. While no member of the Australian Threatened Species Committee thought this number likely, they thought it highly unlikely the total could be as low as 10,000. The total is thus placed here in the band 10,000-19,999 mature individuals but may prove to be higher.
The Atlas reporting rate increased by 61 per cent between the averages for 1977-1981 and 1998-2009.
Polytelis swainsonii is endemic to Victoria and New South Wales, Australia. It has undergone a substantial historical range contraction, and bioclimatic modelling of suitable climatic conditions within its range supports this and suggests that it now occupies a relatively small part of its former range (Manning et al. 2005). In Victoria, it is now largely confined to the Nathalia area, especially Barmah State Forest, birds having disappeared from central and southern areas in the early 1900s, and it has substantially declined in northern Victoria by 1930. In New South Wales, it has declined in the Parkes district since the 1960s. However, its range may have extended to Deniliquin and in northern New South Wales over the same period, and apparent increases have been noted in Canberra. The breeding population was estimated at fewer than 5,000 pairs in the early 1990s and, owing to a likely decline, was thought to number c.6,500 mature individuals in 2000. A study systematically sampling 23,000 km2 of parrot habitat on the western slopes in 2001 (Manning et al. 2007) found nearly 1,500 parrots in 53 out of 81 well-separated sites. Furthermore they were reported from throughout the landscape, not just where there were corridors of trees as had previously been thought essential for the species. A simple extrapolation of these results gives a total population of over 400,000 individuals. While such a figure is unlikely, it is also highly unlikely the total could be as low as 10,000, and an expert review panel considered it highly likely that the population in 2010 exceeded 10,000 mature individuals, probably by many thousands (Garnett et al. 2011). Variation in the recorded abundance of the species, due to its movements, may mask population trends, and compounds the reliability of population estimates (Manning et al. 2007). However, the Atlas reporting rate increased by 61 per cent between the averages for 1977-1981 and 1998-2009, and there is no evidence that increases in Canberra in the last decade have been accompanied by losses elsewhere in the range. The South-West Slopes of New South Wales appear to have become the most important area for the species, perhaps as habitat in other areas deteriorates (Manning et al. 2007).
It nests in the New South Wales and Victorian Riverina in loose colonies in riparian woodland of river red gum Eucalyptus camaldulensis and forages in box woodland. On the slopes of the Great Dividing Range, it forages and nests in box-gum woodland, preferring highly modified, open habitat such as scattered paddock trees on private agricultural land (Manning et al. 2004, 2006). Nesting birds on the South-West Slopes show clear preferences for Blakely's red gum trees E. blakelyi, dead and aging trees in general, and larger trees, as all of these factors are correlated with the presence of suitable nest hollows (Manning et al. 2004). The species also shows a preference for lower elevations in this area, which are dominated by agriculture (Manning et al. 2006), in contrast to the poorer soils and lower temperatures of higher elevations (Manning et al. 2007). In the Riverina, it feeds on the seeds of herbaceous plants, switching to lerp, mistletoe berries, eucalypt flowers and grass seed in winter, and forages up to 15 km from the nest. In contrast, it appears that the most important habitats for breeding birds on the South-West Slopes are within 3 km of nest-sites (Manning et al. 2006).
Range contraction is largely the result of clearing for agriculture. Decreases in the species's abundance are linked to land clearing that does not leave scattered trees in the landscape (Manning et al. 2007). Remaining habitat is often fragmented, with feeding and breeding habitats divided. Regeneration is commonly prevented by high grazing levels by stock and rabbits or inappropriate fire regimes. Scattered box-gum woodland is threatened by limited regeneration, rural tree dieback, removal of trees and firewood collection (Manning et al. 2007). In breeding areas the majority of nest trees are often on private land, with scattered paddock trees in mixed agricultural land of vital importance on the South-West Slopes. Nest-site fidelity means that birds continue to use traditional breeding sites despite habitat loss and degradation (Leslie 2005). Many nest trees are dead, particularly on inland slopes, and have no replacements when they fall or are cut for firewood, potentially resulting in competition with other species, particularly the Common Starling Sturnus vulgaris. There are limited provisions for the protection of dead trees, and due to continued illegal removal and natural loss of old trees a decline in nest site availability is inevitable (Manning et al. 2004). In areas of low occupancy, the availability of food in the breeding season, and not that of nest hollows, may limit population size (Leslie 2005). In the Riverina, altered flooding regimes may compromise the health and extent of riparian woodlands where this species nests (C. Tzaros and M. A. Weston in litt. 2003). Illegal trapping occurs, but is a far less significant threat than habitat loss. Birds are also killed on roadsides and possibly suffer from pesticide poisoning. The abundance and distribution of the species appears to be affected by changes in plant productivity, as influenced by climate (Manning et al. 2007). It is therefore susceptible to climate change and its interaction with fragmentation (Manning et al. 2007).
Conservation Actions Underway
CITES Appendix II. All populations were surveyed in the 1980s, and regular surveys of Barmah State Forest and along Murray, Murrumbidgee and Edward Rivers have been instigated. Annual community-based surveys occur in northern Victoria and southern New South Wales (C. Tzaros and M. A. Weston in litt. 2003). Guidelines have been developed for forestry in riparian breeding habitat, but these have sometimes been inadvertently ignored.
40 cm. Bright green parrot with long, graduated tail. Adult male bright green with diagnostic bright yellow face sharply demarcated by bright red band across lower throat. Mainly grey undertail. Adult female duller than male with bluish-green on face, grey undertail feathers with conspicuous rose-pink edges. Juvenile similar to adult female, but with paler bill. Voice Not well known. One call is prolonged warbling note terminating abruptly or rolling, grating currack currack. Hints Easier to find during breeding season. Dispersive at other times of year.
Text account compilers
McClellan, R., Benstead, P., Pilgrim, J., Garnett, S., Symes, A., Taylor, J., Palmer-Newton, A., Hermes, C.
Manning, A., Weston, M.A., Tzaros, C.
BirdLife International (2020) Species factsheet: Polytelis swainsonii. Downloaded from http://www.birdlife.org on 24/09/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 24/09/2020.