Swift Parrot (Lathamus discolor) Recovery Plan 2001-2005

Swift Parrot Recovery Team (2001)
Tasmanian Department of Primary Industries, Water and Environment
ISBN 0 7246 6283 9

Introduction

Description of Species

The swift parrot Lathamus discolor (White) is a small fast-flying, nectarivorous parrot which occurs in eucalypt forests in south eastern Australia. Bright grass green in colour, the swift parrot has patches of red on the throat, chin and forehead, which are bordered by yellow. It also has red on the shoulder and under the wings and blue on the crown, cheeks and wings. A distinctive alarm call of kik-kik-kik (usually given while flying), a streamlined body, long tail and flashes of bright red under the wing enable the species to be readily identified.

The genus Lathamus is monotypic and belongs to the subfamily Platycercinae, the broad-tailed parrots which includes the genera Platycercus, Barnadius, Purpreicephalus, Northiella, Psephotus and Neophema (Christidis et al. 1991, Higgins 1999). Although the swift parrot superficially resembles lorikeets in habit and form (nectar feeder with brush tongue), it is generally accepted that the similarities between the swift parrot and the lorikeets have arisen through convergence (Smith 1975, Forshaw 1981, Christidis and Boles 1994, Gartrell et al. 2000).

Distribution

Swift parrots breed in Tasmania and migrate to mainland Australia in autumn (Fig. 1). During winter the parrots are semi-nomadic, foraging in flowering eucalypts mainly in Victoria and New South Wales. Small numbers of swift parrots are occasionally recorded in the Australian Capital Territory, south eastern South Australia and southern Queensland.

In Tasmania, the breeding range of the swift parrot is largely restricted to the south east coast within the range of blue gum where it occupies an area of less than 500 km2. There is a smaller breeding population in the north of the state between Launceston and Smithton.

In Victoria, Swift Parrots are found in the dry forests and woodlands of the box-ironbark region on the inland slopes of the Great Dividing Range. There are a few records each year from suburban Melbourne, and in the dry forests and woodlands of the Melbourne and Geelong districts. They are occasionally recorded south of the divide in Gippsland and East Gippsland.

Until recently it was believed that in New South Wales, swift parrots forage mostly in the western slopes region along the inland slopes of the Great Dividing Range but are patchily distributed along the north and south coasts including the Sydney region. However, evidence is gathering that the forests on the coastal plains from southern to northern NSW are also extremely important. There are also records from the Australian Capital Territory in the Canberra area and the Namadgi National Park.

Recent records from southern Queensland have come from the Gold Coast, Noosa, Toowoomba, Warwick and Lockyer Valley areas and records from south-eastern South Australia have come from the Bordertown-Naracoorte area.

Population Size

There have been two surveys of the swift parrot breeding population in Tasmania, one conducted during the 1987/88 breeding season, which located an estimated 1,320 pairs (Brown 1989). Another survey was carried out during the 1995/96 breeding season, which located an estimated 940 pairs. The aim of these surveys was to attempt to locate and count all breeding birds. In the 1999/2000 breeding season a program to estimate the density of swift parrots was initiated using a fixed-stationary observer technique at 65 permanent plots across the range of grassy blue gum forest in eastern Tasmania. These plots form the basis of a repeatable survey program to monitor swift parrot population trends.

There have been eleven winter surveys in the Swift Parrot’s non-breeding range, in 1995 (one) and 1996-2000 (two in each year). The winter surveys comprise weekend counts in May and August, involving over 300 volunteers in Victoria, New South Wales and Queensland. The aim of the winter surveys is not to obtain estimates of population size, but to locate and monitor important foraging areas used by swift parrots. The greatest number of swift parrots located in a weekend survey was on August 5th and 6th 2000, when 1247 birds were recorded.

The breeding season survey data suggest that the swift parrot population is at best stable at an estimated 1000 breeding pairs but may be continuing to decline because of continued habitat loss.

 Distribution of the swift parrot in Australia
Figure 1: Distribution of the swift parrot in Australia

Habitat

During the breeding season, swift parrots occur predominantly in grassy blue gum1 forest in eastern Tasmania where they feed on the nectar from the flowers of these eucalypts (Brereton 1997). Shrubby swamp gum forest is an important food resource early in the breeding season and in years when flowering of Tasmanian blue gum is poor (Brown 1989, Brereton 1997).

Swift parrots nest in hollows in old growth trees across a range of eucalypt species. They prefer stringybark, white peppermint and blue gums with a diameter at breast height over bark greater than 0.8 m. In south-east Tasmania, all recorded nest sites are located within 8 km of the coast, away from foraging areas and often occur in shrubby dry stringybark forest, white peppermint grassy/shrubby dry forest or grassy blue gum dry forest on upper slopes and ridge tops (Brereton 1997). There are also known nesting areas in northern Tasmania in shrubby dry stringybark forest in the Gog Range and Badgers Hills.

Post-breeding habitat is mainly in the wetter forests in west and north-west Tasmania where summer and autumn flowering eucalypt species are abundant, particularly stringybark, alpine ash, white gum, mountain gum and cabbage gum.

The principal over wintering habitat on the mainland is the box-ironbark forests and woodlands inland of the Great Dividing Range in Victoria and New South Wales (Kennedy & Tzaros in press, Kennedy & Overs 2001). Box-ironbark forest is a vegetation type dominated by yellow gum, red ironbark and grey box in central Victoria, and mugga ironbark and grey box in north-east Victoria and the western slopes of New South Wales. The box-ironbark habitats occur across a range of landforms, but drainage lines account for a disproportionately high number of foraging sites. A variety of grassy woodland vegetation types are also used in these areas including white box grassy woodland, grey box grassy woodland and grey box/yellow gum woodland).

Certain forest types on the coastal plains along the eastern seaboard are also important foraging habitats. In lowland coastal forests of New South Wales, swift parrots forage in flowering swamp mahogany, spotted gum and red bloodwood. In south east Queensland and northern New South Wales, narrow-leaved red ironbark/ forest red gum forests and yellow box forest are utilised.

Swift Parrots choose larger trees for foraging within grassy blue gum forest and box-ironbark habitats (Kennedy & Tzaros in press). There is evidence that the parrots also preferentially select larger trees in the forests of the coastal plains of NSW (Kennedy 2000). Factors which contribute to the importance of large trees are that a greater proportion of large trees flower than small trees and large trees have greater canopy foliage than small trees and thus support a greater number of flowers (Wilson and Bennett 1999; Law et. al. 2000).

Table 1. Swift parrot habitats
Habitat type
Habitat
Distribution
Foraging habitat within breeding range Grassy Eucalyptus globulus forest Eastern Tasmania
Grassy/shrubby E. ovata forest Eastern and northern Tasmania
Nesting habitat Old growth forest:
E. obliqua dry forest
E. pulchella grassy/shrubby dry sclerophyll forest
Grassy E. globulus forest
Eastern Tasmania
Old growth E. obliqua dry forest Northern Tasmania
Foraging habitat within overwintering range E. microcarpa / E. tricarpa / E. leucoxylon box ironbark forest Central and Victoria
E. microcarpa grassy woodland Central and western Victoria
E. leucoxylon / E. microcarpa woodland Central and western Victoria
E. microcarpa/E. sideroxylon box ironbark forest North-east Victoria and the western slopes of New South Wales
E. albens grassy woodland Western slopes of New South Wales
E. robusta forest Coastal New South Wales
Corymbia maculata forest Coastal New South Wales
C. gummifera forest Coastal New South Wales
Eucalyptus tereticornis/E. crebra forest Southern Queensland, Northern New South Wales
E. melliodora forest Southern Queensland