Document ID: chunk:federal_register_of_legislation:F2025L00287:reg:3:p51
Version: federal_register_of_legislation:F2025L00287
Segment Type: reg
Provision Reference: reg 3 (pt 51/276)
Character Range: 210063–212961

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 Island robin, the Norfolk Island green parrot, most nesting seabirds including the Kermadec petrel, reptiles, land snails and other invertebrate species (Hicks & Preece 1991; Olsen 1997; Hill 2002; Cogger 2004; Commonwealth of Australia 2005; TSSC 2016a; Brown et al. 2020; Garnett & Baker 2021). Rats are also a threat to some plant species (including Achyranthes arborescens, Melicope littoralis, Meryta latifolia and Ungeria floribunda) through consumption of seeds and fruits, which restricts regeneration (Invasive Species Compendium 2022b).
The Polynesian rat has a negative impact on the breeding productivity of petrels and shearwaters on islands in New Zealand (Pierce 2002) and probably caused the decline of the Lord Howe Island gecko and Lord Howe Island skink on Norfolk Island (Smith et al. 2001). The house mouse is also present on Norfolk Island and eats a range of fruits, seeds and invertebrates. While the impact on biodiversity is unknown, it is likely to adversely affect native flora and invertebrates.

Predation by cats

Feral and free-roaming cats have been identified as a threat to the Norfolk Island green parrot, Norfolk Island golden whistler, Norfolk Island robin, most nesting seabirds, and the Lord Howe Island gecko and Lord Howe Island skink (Olsen 1997; Hill 2002; Cogger 2004; Commonwealth of Australia 2005; TSSC 2016a; Brown et al. 2020; Garnett & Baker 2021).

Predation by other species

The activity of feral chickens represents a threat to many invertebrates, including threatened land snails and flora. Their scratching to uncover food disturbs the leaf litter and soil profiles, causing the micro-environment associated with the litter to become warmer and drier. This change has an impact on nutrient cycling by disrupting invertebrates and fungal species, which has flow on effects for the broader native ecosystem (Christian 2005). Feral chickens also consume snails and damage and remove seedlings, affecting the regeneration of native plant species (Christian 2005).
The purple swamphen—locally known as the 'tarla bird' or 'taalaberd'—was first recorded on Norfolk Island in 1888 and occurs in marsh areas where there is cover nearby (Schodde et al. 1983). There was probably no suitable habitat for the swamphen on the islands prior to European settlement (Smithers & Disney 1969). This species has established on Phillip Island where it is a significant predator of eggs and chicks of terns and petrels, with predation rates on Kermadec petrel nests prior to control efforts measured at 40% (Carlile & O'Dwyer 2018). Other seabird species such as black‑winged petrels and sooty terns are also heavily