Giant Dragonfly - profile

Indicative distribution

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Key:

known

predicted

The areas shown in pink and/purple are the sub-regions where the species or community is known or predicted to occur. They may not occur thoughout the sub-region but may be restricted to certain areas. ( click here to see geographic restrictions). The information presented in this map is only indicative and may contain errors and omissions.

Scientific name: Petalura gigantea

Conservation status in NSW: Endangered

Commonwealth status: Not listed

Gazetted date: 30 Jan 1998

Profile last updated: 04 Mar 2024

Description

The Giant Dragonfly is the third largest dragonfly in Australia and one of the largest dragonflies in the world. Males have an abdomen length of 6 - 7.5 cm, a wingspan up to 11 cm and petal-shaped claspers at the end of the abdomen. Females have an abdomen length of 8 - 9.5 cm and a wingspan up to 12.5 cm, and no claspers. Both sexes have widely-spaced eyes and have a predominantly brownish-black segmented body with light yellow markings along the back and sides. The larvae are also very large, up to 5 cm in length. When the dragonflies emerge from the larvae, they leave behind characteristics shells (exuviae).

Distribution

The Giant Dragonfly is found along the east coast of NSW from the Victorian border to northern NSW. It is not found west of the Great Dividing Range. There are known occurrences in the Blue Mountains and Southern Highlands, in the Clarence River catchment, and on a few coastal swamps from north of Coffs Harbour to Nadgee in the south.

Habitat and ecology

Live in permanent swamps and bogs with some free water and open vegetation.
Adults emerge from late October and are short-lived, surviving for one summer after emergence.
Adults spend most of their time settled on low vegetation on or adjacent to the swamp. They hunt for flying insects over the swamp and along its margins.
Adults fly over the swamp and along its margins hunting for flying insects.
Males sometimes congregate waiting for females to mate with.
Females lay eggs into moss, under other soft ground layer vegetation, and into moist litter and humic soils, often associated with groundwater seepage areas within appropriate swamp and bog habitats. The species does not utilise areas of standing water wetland, although it may utilise suitable boggy areas adjacent to open water wetlands.
Larvae dig long branching burrows under the swamp. Larvae are slow growing and the larval stage may last 10 years or more.
It is thought that larvae leave their burrows at night and feed on insects and other invertebrates on the surface and also use underwater entrances to hunt for food in the aquatic vegetation.

Regional distribution and habitat

Click on a region below to view detailed distribution, habitat and vegetation information.

Threats

Climate change effects such as reduced groundwater, increases in fire frequency and intensity, higher temperatures, and more extreme weather events leading to erosion and degradation of habitat. A progressive contraction and loss of suitable mire habitat for this species, across its range, is predicted.
Inappropriate fire regime (particularly increased fire frequency) caused by bushfire hazard reduction activities and backburning (during wildfire). More intense fire regimes may directly threaten the species (egg and early larval stages particularly), and result in incremental, long-term loss of peat, and contraction and degradation of these mire ecosystems.
Loss of groundwater resources (including perched swamp aquifers) and reduced water quality from longwall mining.
Clearing and development of land through urbanisation resulting in loss of habitat and/or habitat degradation such as reduced water quality, erosion, sedimentation, nutrient enrichment and weed invasion.
Disturbance caused by wildfire and bushfire hazard reduction fire management activities such as construction of access tracks and fuel breaks, slashing, mowing and mechanical hazard reduction.
Groundwater extraction (domestic, agricultural, commercial and public water supply bores).
Increased sedimentation caused by construction, maintenance, and lack of maintenance of unsealed roads and tracks.
Increased stormwater runoff and reduced water quality from impermeable road surfaces entering swamp headwaters leading to erosion and habitat degradation.
Establishment or extension of forestry plantations leading to a reduction in available groundwater during early growth stage.
Weed invasion causing degradation of habitat, including increased shading from invasive shrubs, climbers and pine wildings.
Damage (vegetation removal, disturbance, turbidity) to habitat by domestic stock, feral cattle and pigs.
Walking trails and tracks through swamp habitat and unauthorised use of off-road vehicles, including trail bikes.
Agricultural activities (including grazing) resulting in loss of habitat and habitat degradation such as reduced water quality, erosion, sedimentation, drainage, nutrient enrichment, pesticide application, and weed invasion.
Inappropriate application of pesticides on or adjacent to swamps.
Lack of knowledge of range-wide genetic structure and dispersal ecology.

Recovery strategies

A targeted strategy for managing this species has been developed under the Saving Our Species program; click here for details. For more information on the Saving Our Species program click here

Activities to assist this species

Retain or reintroduce natural water flows to swamp habitats.
Protect swamps from pollution.
Minimise the use of pesticides in and adjacent to swamps.
Reduce urban runoff, sewerage overflows, illegal stormwater connections and groundwater extraction.
Prevent access to swamp habitats by off-road vehicles, bushwalkers or other trampling agents through signage, fencing or re-routing of tracks.
Undertake weed control as required using bush regeneration techniques that will not damage the sensitive swamp habitat.
Exclude pigs and cattle from swamp habitat.
Manage fire trails and unsealed roads to reduce sedimentation impacts.

Information sources

NSW Scientific Committee (1998) Giant dragonfly - Endangered species determination - final. DEC (NSW), Sydney.
Watson, J.A.L., Theischinger, G. and Abbey, H.M. (1991) The Australian Dragonflies: a guide to the identification, distributions and habitats of Australian Odonata. CSIRO, Canberra & Melbourne.

IBRA Bioregion	IBRA Subregion	Known or predicted	Geographic restrictions region

New England Tablelands	Northeast Forest Lands	Known	None
New England Tablelands	Stanthorpe Plateau	Known	None
New England Tablelands	Tenterfield Plateau	Predicted	None
NSW North Coast	Karuah Manning	Known	None
NSW North Coast	Macleay Hastings	Known	None
Other State	Jervis Bay Territory	Known	None
South East Corner	East Gippsland Lowlands	Known	None
South Eastern Highlands	Bungonia	Predicted	None
South Eastern Highlands	Kanangra	Known	None
South Eastern Highlands	Oberon	Known	None
South Eastern Queensland	Clarence Sandstones	Known	None
South Eastern Queensland	Scenic Rim	Known	None
Sydney Basin	Burragorang	Known	None
Sydney Basin	Ettrema	Known	None
Sydney Basin	Jervis	Known	None
Sydney Basin	Kerrabee	Predicted	None
Sydney Basin	Moss Vale	Known	None
Sydney Basin	Pittwater	Known	None
Sydney Basin	Sydney Cataract	Known	None
Sydney Basin	Wollemi	Known	None
Sydney Basin	Wyong	Known	None