Document ID: chunk:federal_register_of_legislation:F2025L00287:reg:3:p131
Version: federal_register_of_legislation:F2025L00287
Segment Type: reg
Provision Reference: reg 3 (pt 131/276)
Character Range: 517921–520683

It almost certainly occurs on other rocky islets but it has not been found on the main island and probably became extinct there prior to European settlement (Cogger et al. 2006). Early European reports expressed surprise at the absence of reptiles on the main island; however, remains of this species have been identified on the main island from deposits dating back to 6,500 BP (Cogger et al. 1979).
Cogger et al. (1979) suggested that a conservative estimate for the population on Phillip Island would be 100,000 individuals. The subsequent removal of rabbits and recovery of vegetation on Phillip Island has provided additional suitable habitat for this species. A 2005 survey suggested this species was likely more abundant on Phillip Island than in 1978, with a population estimate of between 99,000 and 176,000 (Cogger et al. 2006). The growth in range and abundance was considered due to revegetation and expanded habitat.
The distribution within the Norfolk Island Group is shown in Map 16.
Map 16 Distribution of Christinus guentheri
Green shading indicates the islands on which the species has been recorded (Cogger et al. 2006).

Ecology
A nocturnal species that shelters under rocks, in splits in trees, and under man-made shelter during the day. It feeds on beetles, spiders, moths, ants and other insects among the leaf litter; it also hunts in trees and feeds on the nectar of some flowers. It uses rock boulders and rock crevices for shelter and egg-deposition sites. Lays a clutch of 1–3 eggs, and incubation is about 80 to 90 days. Females probably have multiple clutches as gravid females have been reported in November and in March. It forms a significant portion of the prey for the Phillip Island centipede (Cormocephalus coynei; Halpin et al. 2021b), but predation is unlikely to be impacting overall population levels.

Habitat
The species occurs in a range of habitats including primary forest, secondary regrowth forest and lightly grassed or bare rocky islands that are exposed to extreme climatic and physical conditions (Cogger et al. 2006). It has been observed at night on both shrubs and trees but especially on flowering white oak (Lagunaria patersonia) and Phillip Island hibiscus (Hibiscus insularis), where it feeds on the nectar (Cogger et al. 2006). It can also be found on Norfolk Island pine (Araucaria heterophylla) and on the weed species African olive (Olea europaea cuspidata), but it is largely absent from all but the edges of the dense groves of immature olives. Most geckos make only relatively short journeys onto bare ground from the cover of edge vegetation or rock screes.

Threats
The presence of rats and cats on Norfolk Island probably prevents this species from establishing there. The main threats are the