Biodiversity

Species Profile and Threats Database


For information to assist proponents in referral, environmental assessments and compliance issues, refer to the Policy Statements and Guidelines (where available), the Conservation Advice (where available) or the Listing Advice (where available).
 
In addition, proponents and land managers should refer to the Recovery Plan (where available) or the Conservation Advice (where available) for recovery, mitigation and conservation information.

EPBC Act Listing Status Listed as Vulnerable as Christinus guentheri
Recovery Plan Decision Recovery Plan required, included on the Commenced List (1/11/2009).
 
Adopted/Made Recovery Plans Norfolk Island Region Threatened Species Recovery Plan (Director of National Parks (DNP), 2010) [Recovery Plan] as Christinus guentheri.
 
Lord Howe Island Biodiversity Management Plan (NSW Department of Environment and Climate Change (NSW DECC), 2007b) [Recovery Plan] as Christinus guentheri.
 
Policy Statements and Guidelines Survey guidelines for Australia's threatened reptiles. EPBC Act survey guidelines 6.6 (Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC), 2011m) [Admin Guideline].
 
Federal Register of
    Legislative Instruments
Declaration under s178, s181, and s183 of the Environment Protection and Biodiversity Conservation Act 1999 - List of threatened species, List of threatened ecological communities and List of threatening processes (Commonwealth of Australia, 2000) [Legislative Instrument] as Christinus guentheri.
 
State Government
    Documents and Websites
NSW:Lord Howe Island Gecko - profile (NSW Office of Environment and Heritage (NSW OEH), 2012ab) [Internet].
State Listing Status
NSW: Listed as Vulnerable (Threatened Species Conservation Act 1995 (New South Wales): December 2013 list) as Christinus guentheri
Non-statutory Listing Status
IUCN: Listed as Vulnerable (Global Status: IUCN Red List of Threatened Species: 2013.1 list)
Scientific name Christinus guentheri [59250]
Family Gekkonidae:Squamata:Reptilia:Chordata:Animalia
Species author (Boulenger,1885)
Infraspecies author  
Reference  
Other names Phyllodactylus guentheri [1679]
Distribution map Species Distribution Map

This is an indicative distribution map of the present distribution of the species based on best available knowledge. See map caveat for more information.

Illustrations Google Images

The Lord Howe Island and Norfolk Island populations may be two species (Cogger 2014).

The Lord Howe Island Gecko is a pale olive-grey to dark brown, heavily built reptile growing to 8 cm, weighing around 12 g. It is peppered with dark brown spots and a series of six paler, W-shaped tranverse markings, continuous with the paler flanks. The tail has a dull, russet-red mid-dorsal stripe, is whitish/yellow-brown below and peppered with dark brown spots. The species has smooth, small scales, and long, slender fingers and toes (Cogger 2000, NSW OEH 2012ab).

The Lord Howe Island Gecko occurs on Lord Howe Island (in a small area near the main settlement), islands off Lord Howe Island (Blackburn (Rabbit) Island, Roach Island and Balls Pyramid) and islands off Norfolk Island (Phillip Island, Nepean Island and two small rocky islets, Moo-oo Rock, Bird Rock and Green Pool Stone) (Cogger et al. 1993, 2006; NSW OEH 2012ab). The species was apparently extinct from Norfolk Island before human settlement and is only known from sub-fossil remains (Cogger 2014).

An extensive survey of Norfolk Island, Phillip Island, Nepean Island and some small islets off Norfolk island was undertaken in 1978 (Cogger et al. 1983) and in 2005 (Cogger et al. 2006, 2006a). Densities in some areas on Phillip Island are very high, with 34 individuals captured from the lower branches of one small tree in a half-hour period. A population estimate for Fisherman's Hut Rock (part of Phillip Island) based on a three-night mark-recapture program was 679 individuals. Day surveys of the same area found only 10 individuals. The population for Phillip Island is estimated to be between 99 000 and 176 000 (Cogger et al. 2006) and is thought to have increased since the elimination of rabbits (Oryctolagus cuniculus) on the island in 1986 (Cogger et al. 1993).

The species has not been systematically surveyed on Lord Howe Island in recent times, with the last published report being that of Cogger (1971) (DSEWPaC 2011m).

The Lord Howe Island Gecko occurs in closed forest, low open woodland, tussock grassland and rocky islets. The species prefers rocky areas that offer protection, with crevices, rock slabs or boulders embedded in the soil (NSW OEH 2012ab).

On Blackburn Island, the species is common among gentle slopes of loose basalt boulders on the leeward side, especially around the bases of low, windswept trees. Fewer individuals live on the windward side, where there are few boulder piles.

On the Lord Howe Island mainland, the species is restricted to a single, rare habitat type behind Lagoon Beach and at the base of Malabar. The habitat consists of honeycombed beachrock partially embedded in the soil, surrounded by Howea palm forest, in which there is a thick layer of humus formed by leaf litter. The surfaces of the rocks are pitted with holes averaging 1-2 cm in diameter, tunnelling deep into the matrix of the rock. Some tunnels join to form larger chambers. The tunnels appear to provide the only safe shelter site from vertebrate predators. The surrounding humus provides many invertebrate prey items (Cogger 1971).

On Phillip Island, the species occurs over all parts of the island, wherever cover offers protection from the sun. Maximum densities occur on grassy coastal cliffs and among trees and vegetation on boulder slopes in the central valley. In these habitats, the species shelters under rocks, fallen timber and other debris. There may be a difference in habitat preferences of males and females on this island: males predominate in relatively clear slopes beneath White Oak (Lagunaria patersonia) and females predominate in the boulder slopes beneath thickets of the introduced African Olive (Olea africana). In one study, the majority of eggs were found in African Olive thickets (Cogger et al. 1983).

On Nepean Island, the species is abundant throughout the island, sheltering beneath surface rocks, litter and rocky crevices during the day. At night, individuals forage on open sand, rocky cliffs, grassy areas and in the littoral and adjacent splash zones. The largest numbers occur near White Oak thickets (Cogger et al. 1983).

On Bird Rock and Moo-oo Rock, the species shelters beneath rocks partly embedded in the soil, in rock crevices and in particularly high densities near White Oak thickets (Cogger et al. 1983).

The following threatened species may co-oocur with the Lord Howe Island Gecko (NSW OEH 2012ab)

Species Common Name EPBC Act status
Cyanoramphus cookie   Norfolk Island Green Parrot Endangered
Oligosoma lichenigera Lord Howe Island Skink Vulnerable
Advena campbellii Campbell’s Helicarionid Land Snail Critically Endangered
Mathewsoconcha grayi Gray’s Helicarionid Land Snail Critically Endangered
Mathewsoconcha phillipii Phillip Island Helicarionid Land Snail Critically Endangered
Quintalia stoddartii Stoddart’s Helicarionid Land Snail Critically Endangered

Little is known about the age at sexual maturity, life expectancy and natural mortality rates of the Lord Howe Island Gecko. In one study, the adult sex ratio on Phillip Island is close to 1:1, while on Nepean Island it is 1 male : 1.42 females. The adult to juvenile ratio on these islands was 1:0.06 and 1:0.26 respectively (Cogger et al. 1979).

A survey on Lord Howe Island in June 1966 failed to find any gravid (egg-carrying) females (Cogger 1971). Surveys conducted in the Norfolk Island complex in November found some gravid females, while others retained physiology that indicated recent oviposition. Males have been found undergoing active spermatogenesis in November (Cogger et al. 1979).

Clutch size varies from one to three eggs, with a mean of 1.32 (n = 15) (Cogger et al. 1979). Eggs are soft when laid, taking the shape of the surfaces they touch and often adhering to the rock or each other, becoming thick, brittle and calcareous (Cogger 1971). Clutches of up to seven eggs appear to be evidence for communal nesting (Cogger et al. 1983). On Lord Howe Island, eggs are placed in the tunnels in honeycomb beachrock, with new eggs laid upon the shells of hatched eggs (Cogger 1971). On Phillip Island and Nepean Island, nests were found in soil beneath small to large boulders or under fallen timber (Cogger et al. 1983).

Five eggs collected from Lord Howe Island in June were taken to a laboratory and left in a dry jar on a bench experiencing temperatures of 19 °C to 29 °C. Although the laying date was not known, the minimum incubation time for the eggs was from 30 to 39 weeks (Cogger 1971). In another study, eggs collected from Phillip Island and Nepean Island in late November and incubated in the laboratory had a minimum incubation time of 11-12.5 weeks, while one egg laid in the laboratory in December hatched after 13 weeks (Cogger et al. 1983).

Tail loss is common on Phillip Island, with original tails usually only found on juveniles. Loss is believed to be due to intraspecific interactions under high density situations, rather than predation. The only terrestrial predators on Phillip Island are crabs and large centipedes (Cogger et al. 1979).

Two important seasonal sources of food on Phillip Island are nectar, including that of the White Oak (Lagunaria patersonia) and the Swan Plant (Gomphocarpus physocarpus), and the fruit of the succulent herb, Pigface (Carpobrotus sp.) (Cogger et al. 1979, 1983; Stevenson cited in Cogger et al. 1993). Gut contents of specimens collected from Phillip Island included bracts or leaves from flowering plants, anthers and seeds (Cogger et al. 1983). Invertebrates also form a major part of the diet, with the following items occurring in over 20% of the stomachs examined from Phillip Island: spiders, mites, beetles, moths, caterpillars, flies, ants and wasps (Cogger et al. 1983).

Nocturnal activity appears to be unrestricted by the need to thermoregulate, with the thermal activity range for the species differing little from the ambient temperature range (Cogger et al. 1983).

To detect the presence of the Lord Howe Island Gecko, it is recommended that spotlighting be undertaken in the warmer months of the year (November to February). The peak activity period for the species is probably mid-spring to mid-summer. It is a nocturnal species, active on trees and on the coastal rocks, with a peak activity between sunset and the first three hours after dark. It shelters by day under a variety of rocky habitats and presumably also in the hollows of trees (DSEWPaC 2011m).

Cogger and colleagues (1983, 2006, 2006a) successfully undertook day searches under loose rocks, detecting the species at Philip and Nepean Islands and on several smaller offshore islets. Further night spotting on Philip Island resulted in significantly greater numbers of observations.

The Lord Howe Island Gecko is the only native gecko within its range. However, the Asian House Gecko (Hemidactylus frenatus) was first recorded on Norfolk Island in 2005 and was probably an accidental introduction. While these two species are not known to co-occur, there is a high risk that the Asian House Gecko might invade Norfolk’s offshore islands and impact on the ecology of the native gecko. They are very different in size and markings, but the Asian House Gecko may also be distinguished from the Lord Howe Island Gecko by lacking a greatly enlarged pair of terminal pads under the tip of each toe (Cogger 1971; Cogger et al. 2006, 2006a).

Threats to the Lord Howe Island Gecko on Lord Howe Island include:

  • habitat disturbance through weed invasion, trampling and clearing (NSW OEH 2012ab)
  • predation by rat (Rattus spp.), cats (Felis catus) and pigs (Sus scrofa) on the main island (Cogger et al. 1993)
  • accidental introduction of non-native invertebrates (e.g. Red Imported Fire Ant (Solenopsis invicta) or Yellow Crazy Ant (Anoplolepis gracilipes)) or rats on to offshore islands (NSW OEH 2012ab)
  • competition for food resources with the introduced Grass Skink (Lampropholis delicata), which was first detected in the early 1990s and spread from the settlement to the northern hills and Intermediate Hill (Cogger 2004).

Threats to the Lord Howe Island Gecko on islands offshore of Norfolk Island include:

  • accidental introduction of the Asian House Gecko or rats to Phillip and Nepean Islands (Cogger et al. 1979)
  • historic predation by the Pacific Rat (Rattus exulans) which may have been the major cause of decline on Norfolk Island (Cogger et al. 1993)
  • historic habitat destruction by rabbits, pigs and goats (Capra hircus) on Phillip Island; pigs and goats died out naturally, and rabbits were eliminated from the island in 1986 (Cogger et al. 1993).

Activities that could be undertaken to assist the survival of the Lord Howe Island Gecko include (NSW OEH 2012ab):

  • control and eradication of introduced rodents
  • establishment of rodent baiting stations on key offshore islands to prevent establishment of rodents
  • prevention of habitat disturbance caused by weed invasion, trampling and clearing
  • continuation of the vegetation regeneration program on Blackburn Island
  • implementation and monitoring of quarantine plans
  • monitoring the status of populations
  • research into the impacts of the introduced Grass Skink on the food resources of the Lord Howe Island Gecko
  • research into the ecology and genetics of species to provide information to assist in its conservation.

On Lord Howe Island there is an ongoing intensive mouse (Mus musculus) and rat control program (Lord Howe Island Board 2009), a ban on importation of cats (no cats now occur on the island) (NSW DECC 2007b) and the eradication of pigs in the early 1980s (NSW DECC 2007b).

Management undertaken in the Norfolk Island group includes elimination of rabbits on Phillip Island in 1986 and exclusion of rats from a large section of Norfolk Island National Park (Cogger et al. 1993). Ongoing management actions identified for the Norfolk Island group include continued weed control and habitat restoration work on Phillip Island, particularly removal of African Olive and re-establishing stands of White Oak; and establishment of effective quarantine protocols for Phillip Island. Should rats and cats be controlled on Norfolk Island it may be possible to re-establish the Lord Howe Island Gecko there (DNP 2010).

The highly insectivorous diet of the Lord Howe Island Gecko (NSW DECC 2007b) exposes them to the risk of ingesting brodifacoum (used in rodent baiting) if they feed on invertebrates carrying brodifacoum from baits. However, the risk of secondary poisoning is low (Wilkinson & Priddel 2011).

Management documents relevant to the Lord Howe Island Gecko can be found at the start of the profile. Another important management plan is the draft Lord Howe Island rodent eradication plan (Lord Howe Island Board 2009).

The following table lists known and perceived threats to this species. Threats are based on the International Union for Conservation of Nature and Natural Resources (IUCN) threat classification version 1.1.

Threat Class Threatening Species References
Climate Change and Severe Weather:Habitat Shifting and Alteration:Habitat loss, modification and/or degradation Norfolk Island Region Threatened Species Recovery Plan (Director of National Parks (DNP), 2010a) [State Recovery Plan].
Ecosystem/Community Stresses:Ecosystem Degradation:Decline in habitat quality Norfolk Island Region Threatened Species Recovery Plan (Director of National Parks (DNP), 2010a) [State Recovery Plan].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or habitat degradation Oryctolagus cuniculus (Rabbit, European Rabbit) Christinus guentheri in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage (DEH), 2006ey) [Internet].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or predation Felis catus (Cat, House Cat, Domestic Cat) Christinus guentheri in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage (DEH), 2006ey) [Internet].
Norfolk Island Region Threatened Species Recovery Plan (Director of National Parks (DNP), 2010a) [State Recovery Plan].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or predation Rattus exulans (Pacific Rat, Polynesian Rat) Christinus guentheri in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage (DEH), 2006ey) [Internet].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or predation Rattus rattus (Black Rat, Ship Rat) Christinus guentheri in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage (DEH), 2006ey) [Internet].
Norfolk Island Region Threatened Species Recovery Plan (Director of National Parks (DNP), 2010a) [State Recovery Plan].
Lord Howe Island Biodiversity Management Plan (NSW Department of Environment and Climate Change (NSW DECC), 2007b) [Recovery Plan].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition, predation and/or habitat degradation Hemidactylus frenatus (Asian House Gecko) Norfolk Island Region Threatened Species Recovery Plan (Director of National Parks (DNP), 2010a) [State Recovery Plan].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Grazing, tramping, competition and/or habitat degradation Capra hircus (Goat) Christinus guentheri in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage (DEH), 2006ey) [Internet].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Grazing, tramping, competition and/or habitat degradation Sus scrofa (Pig) Christinus guentheri in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage (DEH), 2006ey) [Internet].
Invasive and Other Problematic Species and Genes:Invasive and Other Problematic Species and Genes:Predation, competition, habitat degradation and/or spread of pathogens by introduced species The threat posed by pest animals to biodiversity in New South Wales (Coutts-Smith, A.J., P.S. Mahon, M. Letnic & P.O. Downey, 2007) [Management Plan].
Invasive and Other Problematic Species and Genes:Problematic Native Species:Competition, predation and/or habitat degradation Lampropholis delicata (a skink) Lord Howe Island Biodiversity Management Plan (NSW Department of Environment and Climate Change (NSW DECC), 2007b) [Recovery Plan].

Cogger, H., G. Muir & G. Shea (2006). A survey of the terrestrial reptiles (Christinus guentheri and Oligosoma lichenigera) of Norfolk Island - March 2005: 1. Executive Summary and Background Document. [Online]. Australian Government Department of the Environment, Water, Heritage and the Arts, Canberra. www.environment.gov.au/biodiversity/threatened/publications/pubs/norfolk-island-reptiles-summary.pdf.

Cogger, H., G. Muir & G. Shea (2006a). A survey of the terrestrial reptiles (Christinus guentheri and Oligosoma lichenigera) of Norfolk Island - March 2005: 2. A qualitative assessment of the relative abundance of the Norfolk and Lord Howe Island reptiles. [Online]. Australian Government Department of the Environment, Water, Heritage and the Arts, Canberra. www.environment.gov.au/biodiversity/threatened/publications/pubs/norfolk-island-reptiles-abundance.pdf.

Cogger, H.G. (1971). The reptiles of Lord Howe Island. Proceedings of the Linnean Society of New South Wales. 96 (1):23-40.

Cogger, H.G. (2000). Reptiles and Amphibians of Australia - 6th edition. Sydney, NSW: Reed New Holland.

Cogger, H.G. (2004). Draft recovery plan for the threatened lizards Christinus guentheri and Oligosoma lichenigera on the island complexes of Norfolk and Lord Howe Islands. Canberra: Department of the Environment and Heritage.

Cogger, H.G. (2014). Reptiles and Amphibians of Australia - 7th edition. Collingwood, VIC: CSIRO Publishing.

Cogger, H.G., E.E. Cameron & R.A. Sadlier (1979). The terrestrial reptiles of islands in the Norfolk Island complex. The Terrestrial Reptiles of Islands in the Norfolk Island Complex. Page(s) 1-122. ANPWS. ANPWS, Canberra.

Cogger, H.G., E.E. Cameron, R.A. Sadlier & P. Eggler (1993). The Action Plan for Australian Reptiles. [Online]. Canberra, ACT: Australian Nature Conservation Agency. Available from: http://www.environment.gov.au/biodiversity/threatened/action/reptiles/index.html.

Cogger, H.G., R.A. Sadlier & E.E. Cameron (1983). The terrestrial reptiles of Australia's island territories.:50-52. ANPWS. ANPWS, Canberra.

Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC) (2011m). Survey guidelines for Australia's threatened reptiles. EPBC Act survey guidelines 6.6 . [Online]. Canberra, ACT: DSEWPaC. Available from: http://www.environment.gov.au/epbc/publications/threatened-reptiles.html.

Director of National Parks (DNP) (2010). Norfolk Island Region Threatened Species Recovery Plan. [Online]. Canberra, Director of National Parks Department of the Environment, Water, Heritage and the Arts. Available from: http://www.environment.gov.au/biodiversity/threatened/publications/recovery/norfolk-island.html.

Lord Howe Island Board (2009). Draft Lord Howe Island Rodent Eradication Plan. Lord Howe Island Board, Lord Howe.

NSW Department of Environment and Climate Change (NSW DECC) (2007b). Lord Howe Island Biodiversity Management Plan. [Online]. Sydney, NSW: NSW Department of Environment and Climate Change. Available from: http://www.environment.gov.au/biodiversity/threatened/publications/recovery/lord-howe/index.html.

NSW Office of Environment and Heritage (NSW OEH) (2012ab). Lord Howe Island Gecko - profile. [Online]. Available from: http://www.environment.nsw.gov.au/threatenedspeciesapp/profile.aspx?id=10879.

Wilkinson, I.S. & D. Priddel (2011). Rodent eradication on Lord Howe Island: challenges posed by people, livestock, and threatened endemics. In: Veitch, C.R., M.N. Clout & D.R. Towns, eds. Island invasives: eradication and management. Page(s) 508-14.

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This database is designed to provide statutory, biological and ecological information on species and ecological communities, migratory species, marine species, and species and species products subject to international trade and commercial use protected under the Environment Protection and Biodiversity Conservation Act 1999 (the EPBC Act). It has been compiled from a range of sources including listing advice, recovery plans, published literature and individual experts. While reasonable efforts have been made to ensure the accuracy of the information, no guarantee is given, nor responsibility taken, by the Commonwealth for its accuracy, currency or completeness. The Commonwealth does not accept any responsibility for any loss or damage that may be occasioned directly or indirectly through the use of, or reliance on, the information contained in this database. The information contained in this database does not necessarily represent the views of the Commonwealth. This database is not intended to be a complete source of information on the matters it deals with. Individuals and organisations should consider all the available information, including that available from other sources, in deciding whether there is a need to make a referral or apply for a permit or exemption under the EPBC Act.

Citation: Department of the Environment (2014). Christinus guentheri in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Sun, 24 Aug 2014 06:11:52 +1000.