Document ID: chunk:federal_register_of_legislation:F2025L00287:reg:3:p206
Version: federal_register_of_legislation:F2025L00287
Segment Type: reg
Provision Reference: reg 3 (pt 206/276)
Character Range: 757745–761993

2021 was 350 individuals.
The distribution is shown in Map 39.

Ecology
This species takes 18 years to mature from seed, but plants mature more quickly when propagated from cuttings.
The predatory moths Pectinophora scutigera and Anisoplaca cosmia may reduce reproductive success by destroying seeds (Groeneveld 1989).
H. insularis is pollinated by nectar feeding birds (Groeneveld 1989).

Habitat
Grows on the northern slopes of Phillip Island.

Threats
H. insularis is threatened by small population size and restricted distribution, and subsequent increased risk of extinction through natural events such as cyclones, slips and drought. Existing population has been totally derived from two individuals. Weed invasion and competition (particularly from African olive [Olea europaea cuspidata]) is a significant threat, which may be exacerbated by extended dry periods. Phytophthora cinnamomi is potentially a major risk.
Map 39 Distribution of Hibiscus insularis
Green outlines indicate reserves within which the species occurs. Points show recorded locations (Mills 2009b).

Impact on other species
None known.

Risk assessment
Risk assessment undertaken for Critically Endangered trees/shrubs as a grouping. The risk assessment is shown in Table 95.
Table 95 Risk assessment for Critically Endangered trees/shrubs as a grouping
Risk                                                                                                               Likelihood of exposure    Consequence  Threat rating
1. Loss and fragmentation of native vegetation through past land clearing                                          Almost certain (91–100%)  Extreme      Extreme
2. Loss and fragmentation of native vegetation through current or future land clearing                             Rare (0–10%)              Negligible   Negligible
3. Degradation of native vegetation through past grazing or loss of nutrients                                      Almost certain (91–100%)  Extreme      Extreme
4. Degradation of native vegetation through current or future grazing                                              Possible (26–50%)         Moderate     Medium
6. Predation by rodents                                                                                            Likely (51–90%)           Moderate     Medium
7. Predation by cats                                                                                               Rare (0–10%)              Negligible   Negligible
8. Predation or damage by chickens                                                                                 Likely (51–90%)           Moderate     Medium
9. Predation by swamphens                                                                                          Rare (0–10%)              Negligible   Negligible
10. Predation by Argentine ant                                                                                     Possible (26–50%)         Minor        Low
11. Competition from/change of habitat because of weed invasion                                                    Possible (26–50%)         Minor        Low
12. Infection by pathogens already present                                                                         Possible (26–50%)         Moderate     Medium
13. Impacts of potential new invasive species or pathogens                                                         Unlikely (11–25%)         Minor        Low
14. Changes to vegetation, increased fire risk and/or direct physiological stress as a result of climatic changes  Possible (26–50%)         Minor        Low
15. Problems caused by small populations, including lack of genetic diversity                                      Almost certain (91–100%)  Moderate     High

Management actions
Undertake propagation and planting within suitable areas on Phillip Island. Establish native tree shelter belts (such as white oaks) to replace the weed species that currently shelter the main population on Phillip Island. Undertake targeted weed control and ongoing maintenance, while maintaining a strict herbicide ban in the vicinity of the main population.

Recovery target
The recovery target is shown in Table 96.
Table 96 Recovery target for Hibiscus insularis
EPBC