Indicative distribution
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.
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click here to see geographic restrictions).
The information presented in this map is only indicative and may contain errors and omissions.
Scientific name: Petalura litorea
Gazetted date:
08 Dec 2006
Profile last updated:
14 Oct 2024
Description
The Coastal Petaltail Petalura litorea is closely related to the Giant Dragonfly P. gigantea and is one of the largest dragonflies in Australia. Males have a hindwing of 5.2-5.5cm. Their abdomen is 7-7.9cm with orange petal-shaped claspers at the terminal end used to help grasp the female during mating. Females have a hindwing of 4.9-5.8cm and an abdomen of 5.9-7.4cm, without claspers. Both sexes have widely-spaced eyes and a predominantly brownish-black segmented body with contrasting light yellow linear markings along the back and sides. The larvae are also very large, up to 5cm in length. When the dragonflies emerge from the larvae, they leave behind characteristic shells (exuviae). The Coastal Petaltail is more slender than the Giant Dragonfly, with a better defined and more strongly contrasting colour pattern. There are also differences between the two species in head structure with the Coastal Petaltail more similar to the northern Petalura species than to the Giant Dragonfly.
Distribution
The Coastal Petaltail is known from Byfield (near Yeppoon in Queensland) to Bonville (south of Coffs Harbour). In NSW it is known from a very small number of locations, including Brooms Head, Tucabia, Diggers Camp and Bonville.
Habitat and ecology
- The Coastal Petaltail occupies a variety of permanent to semi-permanent coastal freshwater wetlands.
- Adults emerge from late October to late January and probably live for no more than three months.
- Adults spend most of their time settled on low vegetation on or adjacent to the swamp. They hunt flying insects on the wing over the swamp and around its margins.
- Immediately after mating, females lay eggs into suitable egg laying sites within the swamp.
- Larvae dig long branching burrows under the swamp. They are slow growing and the larval stage lasts at least 10 years.
- 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
- Loss or modification of natural swamps, wetlands and sedgelands through regulation of river flows, water harvesting schemes and changes in surface water flows and groundwater levels.
- Trampling, fouling and rooting of suitable breeding habitat by feral pigs and domestic and feral hard-hooved animals (cattle, pigs, horses, deer). Feral pigs could target Petalura larvae in burrows at certain times, as they do for burrowing crayfish. These animals can cause significant damage to peat swamp soils and vegetation.
- Weed invasion of suitable breeding habitat, particularly by invasive grasses such as Setaria sphacelata, Paspalum urvillei, and Andropogon virginicus, and shrubs such as Baccharis halimifolia and Lantana camara, which reduces habitat quality.
- Application of herbicides or pesticides in or adjacent to breeding habitat.
- Damage to critical habitat by chemical retardants, chemical additives and gels applied during fire suppression. Inappropriate use of chemical retardants can destroy sensitive vegetation and soil profile, change soil/peat chemistry, increase weed invasion, damage hydrology, and reduce water quality
- Maintenance of unsealed roads and associated drainage works within or near swamp breeding habitat has the potential to alter the hydrology and cause sedimentation, erosion, or drying of adjoining swamp habitat when surface waters are diverted.
- Modification of swamps due to climate change, particularly too frequent heavy rainfall, which can lead to increased erosion, or sea level rise potentially inundating nearby freshwater peat swamps or causing salt-water intrusion into freshwater lenses below swamps in coastal sand systems. Changes in surface hydrology result in extended periods of inundation which reduces ovipositing opportunities and is likely deleterious to the species during the long larval stage. Climate change may result in an intensification in fire regimes.
- Lack of knowledge of distribution, abundance and ecology
- Inappropriate fire regimes (too severe and too intense), including risk from uncontrolled fires and hazard reduction burns, particularly during extended drought. Drought impacts breeding habitat by surface drying of swamp peat substrates, reducing availability of suitable moist/wet substrates for egg-laying, and reducing ground water levels, which may negatively affect recently laid eggs, early-stage larvae, and established larvae in burrows. Fire during periods of drought, in particular, can result in combustion of organic-rich/peaty swamp soils and mortality of eggs and larvae, especially early-stage larvae before burrow establishment. Fire during the flying and emergence season, (spring and summer) may kill adults. Where peat combustion/oxidization occurs during and post-fire at a rate greater than the rate of peat accumulation, then long-term and potentially irreversible degradation of peat swamp ecosystems and progressive loss of breeding habitat occurs. Climate change may result in an intensification in fire regimes.
- Loss and degradation of habitat (including water impoundment, habitat destruction, drainage, groundwater extraction, pollution and pesticide use) due to coastal and agricultural development, particularly on the northern coastal parts of the species range.
- Lack of information on population size or health including if there are critical threats from disturbance as a part of major road realignments
- Uncertainty of future land management practices on private tenure where the species, or species habitat is present.
- Risk to ground water from coal seam gas extraction, lowering water tables and reducing the area of suitable habitat for ovipositing and larval burrowing
Recovery strategies
A Saving Our Species conservation project is currently being developed for this species and will be available soon. For information on how you can contribute to this species' recovery, see the Activities to assist this species section below.
Activities to assist this species
- Protect swamps from fire during burning-off or hazard reduction activities.
- Retain or reintroduce natural water flows to swamp habitats.
- Protect wetland areas from pollution particularly by minimising the use of pesticides in and adjacent to swamps.
- Control invasive weeds.
- Protect known and potential breeding habitat from modification and disturbance, particularly by feral pigs and domestic stock.
Information sources
- Clarke, G.M. and Spier-Ashcroft, F. (2003) A review of the conservation status of selected Australian non-marine invertebrates.
- Theischinger, G. (1999) A new species of Petalura Leach from south-eastern Queensland (Odonata: Petaluridae) Linzer biol Beitr. 31: 159-166
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