Appendix 1. Summaries of selected exemplar species details and literary references as relevant to invasiveness on Barrow Island, as a basis for elicitation workshops, which in combination formed the underlying ecological model for each exemplar species.

Exemplar species / Rattus rattus L. / Mus musculus subsp. domesticus L. / Lepidodactylus lugubris (Duméril and Bibron, 1836) / Litoria rubella (Gray, 1842) / Cryptoblepharus ustulatus (Horner, 2007) / Antaresia perthensis (Stull, 1932)
Exemplifies / Rattus exulans and
Rattus norvegicus (both already globally invasive species). / Suncus murinus (widespread invaders of the Indian Ocean), and
other small murine and marsupial species native to mainland Australia. / Hemidactylus frenatus (recorded at the nearby port in Dampier (Biota Environmental Sciences Pty Ltd 2006)), and
other gecko species (e.g. Gehyra) native to mainland Australia. / Chaunus [Bufo] marinus (although this species has not yet reached the Pilbara region (Phillips et al. 2008)), and other frogs native to mainland Australia. / Other skinks native to mainland Australia. / Other snakes native to mainland Australia.
Occurrence / Native to India; now widespread throughout tropical and temperate zones of the world, as well as sub-Antarctic Islands. R. rattus has been widely distributed on Australian Islands (Abbott and Burbidge 1995). Morris (2002) provides a detailed history of the Black rat on Barrow and surrounding Islands. / Mus musculus spread from south central Asia to every continent (and many oceanic islands) except Antarctica (Caughley et al. 1998; Pocock et al. 2005). In Australia, M. domesticus are distributed over the entire mainland and Tasmanian island as well as many off shore islands (Singleton 1995). / L. lugubris is a species that comprises four major clones (Harfmann Short and Petren 2008), and as such is referred to as a complex.
L. lugubris originated in south east Asia and spread across the Pacific recently, probably via human transport (Moritz et al. 1993). / Occupies most of Australia, except the far south, and also occurs in southern New Guinea (Cogger 1996). / This species has recently been named, therefore there is limited information available specific to this species. Cryptoblepharus plagiocephalus and C.megastictus are reasonable ecological homologues, and their ranges include arid regions of mainland Australia. / A. perthensis is distributed in mid-western Western Australia, centered on the Pilbara region (Cogger 1996).
General description and biology / Medium sized brown-grey rat, there are three colour morphs; for further physical descriptions see (Key et al. 1998; Watts 1995). Burrowing social species (Alpin et al. 2003; Dowding and Murphy 1994; Pye et al. 1999); predominantly nocturnal and omnivorous (Clark 1982; Copson 1986; Key et al. 1998; Watts and Braithwaite 1978). Reproductive fecundity results in rapid population growth (Caughley and Krebs 1983)
Home ranges of 0.5 to 1.0ha (Dowding and Murphy 1994). / Moderately large brown-grey mice (Alpin et al. 2003; Singleton 1995) . Opportunistic colonizers well adapted to live in a range of feral and commensal habitats (Alpin et al. 2003), generally occurs in low densities but has plague cycles (Pocock et al. 2004). Omnivorous and can be social (Caughley et al. 1998). In commensal populations they have a polygynous mating system with a social group territoriality and are male dispersed (Patris et al. 2002). / The diet of L. lugubris consists of insects (Petren and Case 1996). Most productive foraging occurs near lights (Petren and Case 1996). L. lugubris has been found to reproduce throughout the year in a subtropical area (Ota 1994). Females have two eggs per clutch (Cogger 1996). / L. rubella breeds after summer rains on the Australian mainland (Cogger 1996). Eggs (40 to 300) are laid on static water (Tyler et al. 1994) and larval period is short. L. rubella can be found in a range of habitats from wet coastal forests to arid deserts (Cogger 1996), and has adapted to arid environments (Main and Bentley 1964; Tyler et al. 1994). Advertisement call is a long harsh, vibrant loud screech, sounds like a seagull (Tyler et al. 1994). Diet consists of insects (Tyler 1994). / Cryptoblepharus spp. are small smooth-scaled climbing skinks, that are active and seek small insects for food, on vertical surfaces such as tree trunks, rocks, and walls (Cogger 1996; Horner 2007; Storr et al. 1981).
Skinks are generally carnivorous and largely eat insects. C. ustulatus has 3 to 4 eggs once or twice per year. / A. perthensis has smooth scales and is a small python (Cogger 1996).
A. perthensis have been found inhabiting the tunnels of giant termitaria and feeding on geckos (Cogger 1996). Diet consists of lizards and small mammals.
It is thought that reproductive age takes many years to reach for A. perthensis and it is uncertain how often they breed (Shine and Slip 1990).
Invasive characteristics / Highly fecund, short gestation, young reach sexual maturity in a short time after birth, and can breed thoughout the year (Alpin et al. 2003; Caughley et al. 1998; Watts 1995). Utilizes a large range of habitat types and a large variety food sources (Watts and Braithwaite 1978). Rats can swim in open water (Innes 2005; Russell et al. 2005). / Reproductive fecundity results in rapid population growth, see (Alpin et al. 2003; Caughley et al. 1998; Moro and Morris 2000b; Singleton 1995)They actively disperse (Pocock et al. 2005), often hide in their food supply, and do not require water and can reproduce in transit (Pocock et al. 2005). / Parthenogenic species have the ability to found new populations from single individuals. L. lugubris is bold and seem to thrive in human altered environment. Geckos can stowaway as both adults and eggs (Biota Environmental Sciences Pty Ltd 2006) / L. rubella is a relatively robust hardy frog (Tyler et al. 1994) able to cope in arid environments (Main and Bentley 1964; Tyler et al. 1994). / C. ustulatus is small, cryptic and well suited to an arid environment, therefore likely to successfully establish on BarrowIsland. / It is thought that reproductive age takes many years to reach for A. perthensis.
Impacts / Numerous studies globally that show indigenous species declines and extinctions associated with R. rattus (Clark 1980; Jones et al. 2008; Towns et al. 2006) including species of mammals, birds, reptiles and amphibians. / Their presence attracts birds of prey, putting predator pressure on other native species, they compete with native species for food, remove seed potentially altering vegetation composition, contribute to soil erosion, and transmit disease (Caughley et al. 1998; Pocock et al. 2004). / Invasive geckos displace residents by monopolising limited resources and that this competitive advantage may be enhanced in human altered habitats which are structurally simple (Case and Bolger 1991; Greer 1989; Harfmann Short and Petren 2008; Petren and Case 1996, 1998). / There are no published data on the consequences of L. rubella as a non-indigenous species. Cyclorana cultripes, the only frog recorded at Barrow Island (Butler 1970), or other species occupying similar habitat could potentially be displaced. / There are no published data on the consequences of C. ustulatus as an MIS, Skinks naturally occur in low densities, and it is probable that would be slow to colonise a new area. C. ustulatus is a rocky dwelling species and not likely to displace the indigenous tree dwelling C. plagiocephalus. / There are no published data on the consequences of A. perthensis as a non-indigenous species. However, other non-indigenous species of snakes have had serious impacts on islands in other parts of the world (e.g. Bioga irregularis (Fritts and Rodda 1998)).
Detection / Due to neophobic, trap shy, and atypical behaviors of new arrivals, detection of rats at low densities can be difficult (Clapperton 2006; Dilks and Towns 2002; Russell et al. 2008; Russell et al. 2007; Russell et al. 2005).
Surveillance devices and baits have been described (Pye et al. 1999; Spurr et al. 2007; Tobin et al. 1997; Weihong et al. 1999). / Mus spp. are generally detected by types of live trapping (Krebs et al. 1994; Moro and Morris 2000a, b), or cameras (Wanless et al. 2007), although traps shyness may be a problem (Krebs et al. 1994). / L. lugubris is generally observed under lights feeding at dusk (Petren and Case 1996). / L. rubella requires open water to breed, and has a conspicuous moisture conserving posture and perches. These distinctive behaviour may aid in its recognition and detection. / Skinks generally like basking in the sun, but shy away from noise and movement associated with human activities.
Cryptic species can be difficult to detect due to their behaviours. / A. perthensis is usually sighted on roads or crossing road, and the best time for sighting the species is during feeding time at night.
Eradication / There are many accounts of successful eradication of R. rattus, when in large numbers - usually by trapping and baiting (rodenticides) (Howald et al. 2007; MacKay and Russell 2005; Micol and Jouventin 2002; O'Connor and Eason 2000; Russell et al. 2009). Re-invasions can be rapid (MacKay and Russell 2005; Russell et al. 2009). / Population control is usually by baiting (rodenticide) (Caughley et al. 1998; MacKay et al. 2007). / To the knowledge of the authors’ no control methods have been reported. / To the knowledge of the authors’ no control methods have been reported. / To the knowledge of the authors’ no control methods have been reported. / To the knowledge of the authors’ no control methods have been reported.

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