Document ID: chunk:federal_register_of_legislation:F2025L00287:reg:3:p50
Version: federal_register_of_legislation:F2025L00287
Segment Type: reg
Provision Reference: reg 3 (pt 50/276)
Character Range: 207323–210307

threatening processes, and 75% of the known extinctions since the global European expansion have occurred on islands (Fernandez‑Palacios et al. 2021). Tallied taxonomically, 94% of birds, 90% of reptiles, 54% of mammals and 68% of vascular plants known to have gone extinct once inhabited islands (Fernandez‑Palacios et al. 2021). The major threatening processes on oceanic islands are anthropogenic: habitat fragmentation and loss, invasive species, and introduced pathogens (Borges et al. 2020). After habitat loss, invasive species are the main cause of ecological disintegration globally and are likely the main cause of ongoing extinctions in island ecosystems (Tershy et al. 2015; Munstermann et al. 2022).
Typical of small oceanic islands, the Norfolk Island Group has suffered significant species loss due to the impacts of human habitation and the introduction of exotic species. Since European settlement six species of endemic land birds have become extinct, and several species of land snails, at least one plant species and one endemic land bird are presumed extinct. Some seabird species which were once abundant on Norfolk Island now only occur in small numbers on Phillip Island.
While pressures are considered individually by the plan, it is unlikely that a pressure is ever acting in isolation. The ecological changes observed are most frequently a reaction to multiple pressures acting in combination and having an additive, synergistic or antagonistic effect. Many pressures are ongoing and have long-term effects, and cumulative impacts occur if pressures are acting simultaneously or in the same location at a different time. The compounding effects of pressures erode ecosystem resilience, and it is this cumulative impact that has led to most of the decline in threatened species observed (Kearney et al. 2023). While it is unlikely that managing a single pressure will improve the trajectory of threatened species, it is important to understand each pressure individually and establish appropriate pressure-specific management actions and targets.
The pressures identified in this section apply to the Norfolk Island Group as a whole and multiple populations of taxa covered by the plan. Note that 'pressures' and 'threats' are used interchangeably with the same meaning in this plan.

Predation by invasive vertebrates
There are several introduced vertebrate species that pose significant threats to the native species of Norfolk Island. These include rodents, free-roaming cats and feral chickens (Gallus gallus) as well as species native to mainland Australia such as the purple swamphen (Porphyrio porphyrio) and the nankeen kestrel (Falco cenchroides).

Predation by rodents

There are three introduced rodent species on Norfolk Island: the black rat (Rattus rattus), the Polynesian rat (R. exulans) and the house mouse (Mus musculus).
Predation by the black rat has been identified as a specific threat to the Norfolk Island golden whistler, the Norfolk