Document ID: chunk:federal_register_of_legislation:F2025L00287:reg:3:p161
Version: federal_register_of_legislation:F2025L00287
Segment Type: reg
Provision Reference: reg 3 (pt 161/276)
Character Range: 605851–610149

cats on Norfolk Island and predation of nests by swamphens on Phillip Island. Loss of habitat to significant revegetation can limit areas of breeding. Offshore windfarms along the east coast of Australia may represent an emerging threat due to turbine strike.

Impact on other species
None known.

Risk assessment
The risk assessment is shown in Table 55.
Table 55 Risk assessment for Onychoprion fuscata
Risk                                                                                                               Likelihood of exposure    Consequence  Threat rating
1. Loss and fragmentation of native vegetation through past land clearing                                          Likely (51–90%)           Major        High
2. Loss and fragmentation of native vegetation through current or future land clearing                             Unlikely (11–25%)         Minor        Low
3. Degradation of native vegetation through past grazing or loss of nutrients                                      Likely (51–90%)           Major        High
4. Degradation of native vegetation through current or future grazing                                              Unlikely (11–25%)         Negligible   Negligible
5. Lack of available nest sites                                                                                    Rare (0–10%)              Negligible   Negligible
6. Predation by rodents                                                                                            Possible (26–50%)         Minor        Low
7. Predation by cats                                                                                               Unlikely (11–25%)         Negligible   Negligible
8. Predation or damage by chickens                                                                                 Rare (0–10%)              Unknown      Unknown
9. Predation by swamphens                                                                                          Almost certain (91–100%)  Major        Extreme
10. Predation by Argentine ant                                                                                     Possible (26–50%)         Major        High
11. Competition from/change of habitat because of weed invasion                                                    Unlikely (11–25%)         Minor        Low
12. Infection by pathogens already present                                                                         Unlikely (11–25%)         Negligible   Negligible
13. Impacts of potential new invasive species or pathogens                                                         Possible (26–50%)         Unknown      Unknown
14. Changes to vegetation, increased fire risk and/or direct physiological stress as a result of climatic changes  Likely (51–90%)           Major        High
15. Problems caused by small populations, including lack of genetic diversity                                      Unlikely (11–25%)         Minor        Low

Management actions
Continue control of swamphens on Phillip Island and experiment with new control approaches. Protect nesting areas from woody weed invasion. Retain status of pest-free Phillip Island through detection monitoring for introduced vertebrates and invertebrates. Use drone mapping of colony extent on Phillip Island annually in December as a proxy to detect significant changes in populations.

Relevant literature
Blakers M, Davies SJJJF & Reilly PM (1984) An atlas of Australian birds. Royal Australasian Ornithologists Union, Melbourne University Press, Melbourne.
Carlile N & O'Dwyer T (2023) Conservation of the surface-nesting Kermadec Petrel Pterodroma neglecta neglecta in the South Pacific: Clarifying breeding ecology and the threat of avian ground predators. Bird Conservation International 33, e44, 1–9.
Christian M (2005) Norfolk Island … the birds. Green Eyes Publications, Norfolk Island.
Feare CJ (1976) The breeding of the Sooty Tern Sterna fuscata in the Seychelles and the effects of experimental removal of its eggs. Journal of Zoology 179(3), 317–360.
Fullagar PJ (1978) Norfolk Island birds. Unpublished report to RAOU Congress, Norfolk Island.
O'Neill L (2006) The breeding and feeding ecology of the Sooty Tern Sterna fuscata on Lord Howe Island. PhD Thesis, Charles Sturt