Introduction

Globally the introduction and spread of invasive species is a leading cause of biodiversity loss. Invasive species are particularly destructive to island species and ecosystems. Nearly two-thirds of recent extinctions (Jones et al. 2016) and 75% of all recorded terrestrial vertebrate extinctions occurred on islands and most were caused fully or in part by invasive species (McCreless et al. 2016). Currently, 40% of species threatened with global extinction are from island. Eradication of invasive mammals has recently been modelled as having the potential to prevent up to 75% of extinctions of threatened species on islands (ibid).  

Exotic rodents, particularly ship rats and perhaps mice, have been a key (and often the critical) cause of extinction, extirpation (local population loss) and decline of many native species, adverse changes to island ecosystems, as well as economic damage to island peoples’ livelihoods and potentially to their health (DEWHA, 2009). Ship rats alone are responsible for the severe decline or extinction of at least 60 vertebrate species (Towns et al. 2006), and currently endanger more than 70 species of seabird worldwide (Jones et al. 2008). They suppress plants and are associated with the declines or extinctions of flightless invertebrates, ground-dwelling reptiles, land birds and burrowing seabirds (Towns et al. 2006). Mice have also been shown to impact on plants, invertebrates and birds (Angel et al. 2009).  

On LHI, rodents are implicated in the extinction of at least five endemic birds and at least 13 invertebrates (DEWHA, 2009). They are also recognised in the LHI Biodiversity Management Plan (DECC, 2007) as a threat to at least 13 other bird species, 2 reptiles, 51 plant species, 12 vegetation communities and numerous threatened invertebrates on the island (ibid) including the listed threatened species in the table below.

Lord Howe Island Biodiversity Management Plan 2007

Listed Species Currently Impacted by Rodents on the LHIG

TSC Act Listed Species Currently Impacted by Rodents on the LHIG (from DECC, 2007 and Carlile et al. 2016)
CE = Critically Endangered, E = Endangered, V = Vulnerable
 Common NameScientific NameEndemicTSC Act
BirdsBlack-Winged PetrelPterodroma nigripennis-V
Flesh-Footed Shearwater Ardenna carneipes-V
Grey TernletProcelsterna cerulea-V
Kermadec PetrelPterodroma neglecta -V
Little ShearwaterPuffinus assimilis-V
Lord Howe WoodhenHypotaenidia sylvestrisYesV
Masked BoobySula dactylatra-V
Providence PetrelPterodroma solandri-V
White-bellied Storm PetrelFregetta grallaria-V
ReptilesLord Howe Island GeckoChristinus guentheri-V
Lord Howe Island SkinkOligosoma lichenigera-V
InvertebratesLord Howe Island PhasmidDryococelus australisYesCE
Lord Howe PlacostylusPlacostylus bivaricosusYesE
Whitelegge’s Land SnailPseudocharopa whiteleggeiYesCE
Masters’ Charopid Land SnailMystivagor mastersiYesCE
Mt Lidgbird Charopid Land SnailPseudocharopa lidgbirdiYesCE
Magnificent Helicarionid Land SnailGudeoconcha sophiae magnificaYesCE
Lord Howe Island EarthwormPericryptodrilus nanusYesE
Lord Howe Island Wood-feeding CockroachPanesthia lataYesE
PlantsLittle Mountain PalmLepidorrhachis mooreanaYesCE
Phillip Island Wheat GrassElymus multiflorus var. kingianus-CE

Birds

Typical of remote oceanic islands, the terrestrial vertebrate fauna of the LHIG is dominated by birds. One hundred and eighty two species of birds are recorded from the LHIG, of which 20 are resident landbirds, 14 are breeding seabirds, 17 are regular visitors and 120 are vagrants (McAllan et 2004). At the time of European settlement the native avifauna consisted of 26 species of land […]

Reptiles

Two species of reptile (the Lord Howe Island Gecko Christinus guentheri and the Lord Howe Island Skink Cyclodina lichenigera) complete the indigenous terrestrial vertebrate fauna of the LHIG at the time of European settlement. The two reptiles also occur on Norfolk Island. Both reptile species on Lord Howe Island are currently impacted by rodents: Lord Howe Island Gecko Christinus Guentheri Pale olive-grey to dark brown gecko, […]

Invertebrates

The terrestrial invertebrate fauna of the LHIG is characterised by relatively high species richness and high endemism with up to 60% of some groups comprising endemic species. More than 1600 terrestrial invertebrate species have been recorded, including 157 land and freshwater snails, 464 beetles, 27 ants, 183 spiders, 21 earthworms, 137 butterflies and moths and 71 springtails. The rate of discovery of new species remains high, indicating that numerous endemic […]

Plants

There are 239 species of indigenous vascular plant recorded from the LHIG, of which 113 (47%) are endemic. The high degree of endemism is illustrated not only at the species level, but also at the generic level, where there are five endemic vascular plant genera (Negria, Lordhowea, Howea, Lepidorrhachis and Hedyscepe) (Hunter 2002). The non-vascular flora of terrestrial and freshwater habitats (bryophytes, lichens and freshwater algae) is less […]