Document ID: chunk:federal_register_of_legislation:F2025L00287:reg:3:p52
Version: federal_register_of_legislation:F2025L00287
Segment Type: reg
Provision Reference: reg 3 (pt 52/276)
Character Range: 212715–215672

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 impacted (Carlile & O'Dwyer 2018).
The nankeen kestrel was first recorded on the island in 1969. Through much of the 1970s, kestrels were regarded as rare non-breeding visitors. The first breeding pair was reported in 1978 (Schodde et al. 1983) and by 1990 there were at least five breeding pairs (Bell 1990). They are now common and widespread across the island (M Christian 2024, pers comm 12 January). Kestrels have been reported feeding on Norfolk Island robin, Norfolk Island golden whistler, white tern (Gygis alba), grey ternlet (Anous albivittus albivittus) and sooty tern (Onychoprion fuscata) (Garnet & Crowley 2000; S Gorta 2024, pers comm 11 January). The significance of this predation is not well understood, but they are known to prefer open areas such as cleared fields.

Other impacts of introduced vertebrates
In addition to the invasive vertebrate predators, several other introduced vertebrate species negatively impact Norfolk Island's native species either through competition or by degrading habitat.

Competition

Introduced birds such as the crimson rosella (Platycercus elegans; known locally as the red parrot) and the European starling (Sturnus vulgaris) compete for nest hollows with the Norfolk Island green parrot and the Norfolk Island morepork (Hill 2002; TSSC 2016a; TSSC 2016b). Rosellas fill hollows with nesting material such that the sites cannot be used by the native species (Hermes et al. 1986). The common blackbird (Turdus merula) and song thrush (T. philomelos) have also been suggested as potential threats to the whistler and robin; however, there is little evidence to support the claim (Robinson 1988). Additionally, an increase in the population of California quail (Callipepla californica) on Norfolk Island—a possible result of successful rat control given that rats are a significant predator of the species—may impact biodiversity (Rasheed et al. 2018); however, this potential impact is currently not well understood.
The Asian house gecko, which occurs on Norfolk Island, is a potential threat to the Lord Howe Island gecko if it becomes established on Phillip Island or the other outlying islands. This widely distributed species is commensal with humans and has been implicated in the decline of native gecko species elsewhere in its introduced range (Cole et al. 2005; Csurhes & Markula 2009).

Grazing by domestic herbivores

Since European settlement there has been extensive loss of vegetation cover and diversity on Norfolk Island through cattle (Bos taurus) grazing (Neuweger et al. 2001). Cattle grazing has documented impacts on plant species such as Achyranthes arborescens, Boehmeria australis australis, Elatostema montanum, Ptisana salicina,