Document ID: chunk:federal_register_of_legislation:F2025L00287:reg:3:p137
Version: federal_register_of_legislation:F2025L00287
Segment Type: reg
Provision Reference: reg 3 (pt 137/276)
Character Range: 536198–539932

food for nesting females (Greene 2003; Ortiz-Catedral et al. 2009).
Nests in hollows of living trees often within two metres of the ground or at ground level among tree roots. Adults return to the same nest site each season but will also use other sites within their territory.
Diet is a variety of seeds, fruits, flowers, pollen, sori, sprout rhizomes and bark, taken from at least 30 native and introduced plant species.
Active foraging is mostly at heights of 2–7 metres, although the parrots also feed on the ground, especially in winter (Waldman 2016). They have some overlapping dietary preferences with the crimson rosella, although there are seasonal differences (Simmonds 2019).

Habitat
The breeding range is thought to be largely restricted to the Mt Pitt section of the national park, though successful nesting has been recorded outside the park (D Gautschi 2024. pers comm 12 January). The species forages in the park and adjacent forested areas and orchards.

Threats
The main factors responsible for the decline of the species were clearance of vegetation for agriculture, particularly trees with suitable nesting hollows, and predation from introduced predators. Change in forest structure due to weed invasion is likely to also have reduced the area of suitable habitat available to the species (Garnett et al. 2011; TSSC 2016a). Predation of eggs and chicks by rats and cats, a shortage of suitable predator-free nest sites, and nest hollow competition from introduced crimson rosellas (which have a population three times that of the Norfolk Island green parrot (TSSC 2016a; Skirrow 2019)) are the main factors limiting population recovery (Macgregor et al. 2021), while disease may be a significant cause of mortality in certain circumstances (Hill 2002). The purple swamphen, a self-introduced species that arrived on the Norfolk Island Group before 1888, may prevent re-establishment on Phillip Island (Heinsohn 2019).

Impact on other species
None known.

Risk assessment
The risk assessment is shown in Table 47.
Table 47 Risk assessment for Cyanoramphus cookii
Risk                                                                                                               Likelihood of exposure    Consequence  Threat rating
1. Loss and fragmentation of native vegetation through past land clearing                                          Almost certain (91–100%)  Moderate     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                                      Almost certain (91–100%)  Moderate     High
4. Degradation of native vegetation through current or future grazing                                              Likely (51–90%)           Minor        Medium
5. Lack of available nest sites                                                                                    Almost certain (91–100%)  Moderate     High
6. Predation by rodents                                                                                            Almost certain (91–100%)  Major        Extreme
7. Predation by cats                                                                                               Almost certain (91–100%)  Major        Extreme
8. Predation or damage by chickens                                                                                 Rare (0–10%)              Negligible   Negligible
9. Predation by swamphens                                                                                          Rare (0–10%)              Moderate     Negligible
10. Predation by Argentine ant