Literature review: Impact of Chilean needle grass ... - Weeds Australia

Table 17. Endangered reptile species in south-eastern Australian native temperate grasslands. U = unlisted,V= vulnerable, E =
endangered, T = threatened.
Species Common Name ACT NSW SA Vic References
Delma impar Fischer Striped Legless Lizard V V/E E V Coulson 1990, Kukolic 1994, Sharp and
Shorthouse 1996, Eddy et al. 1998,Webster
et al. 2003, Keith 2004, O’Shea 2005,
Department of Sustainability and
Environment 2009a
Tympanocryptis pinguicolla
(Mitchell)
Eulamprus tympanum
marnieae (Lvnnberg and
Andersson)
Aprasia parapulchella
Kluge
Grassland Earless Dragon E E E Sharp and Shorthouse 1996, Eddy et al.
1998, Brereton and Backhouse 2003, Keith
2004, ACT Government 2005, Department
of Sustainability and Environment 2009a
Corangamite Water Skink - - - T Department of Sustainability and
Environment 2007
Pink-tailed Worm Lizard,
Pink-tailed Legless Lizard
E or
V
Suta flagellum Eastern Whip Snake E or
V
Varanus rosenbergii Rosenbergs Monitor E or
V
E T Sharp and Shorthouse 1996,Eddy et al. 1998,
Keith 2004, Department of Sustainability
and Environment 2009a
E or
V
E or
V
T
Eddy et al. 1998
Eddy et al. 1998, Department of
Sustainability and Environment 2009a
Delma impar, Striped Legless Lizard (Pygopodidae)
Delma impar Fischer is one of 38 species in the Pygopodidae, a family of mostly surface active, fossorial or semi-fossorial,
arthropod-eating lizards, endemic to Australia except for two species in Papua New Guinea, and most closely related to
diplodacytline Geckonidae (O’Shea 2005). It is the most southerly occurring of the 17 Delma spp., is considered to be a diurnal,
semi-fossorial species, active from September to late March or April (O’Shea 2005). It is slow growing, and could live for up to
20 years (O’Shea 2005). According to Hadden (1995) D. impar had been recorded at 125 sites from the South East of South
Australia, through eastern and northern Victoria to southern NSW and the ACT, of which possibly 45 were then considered still
capable of supporting it. Additionally O’Shea (2005) mapped recent records from the South East of South Australia. The lizard’s
rarity was considered to be due to its specificity to lowland grassland habitat and the widespread loss and degradation of such
habitats. Western (Basalt) Plains Grassland was the major vegetation type occupied in Victoria (Webster et al. 2003). Population
densities were reportedly highest in dense, relatively undisturbed native grassland, although capture rates were relatively high in
an area dominated by Nassella trichotoma and total grass cover appeared to be the best predictor of population density (Coulson
1990). Most of the extant sites (Hadden 1995) were native perennial tussock grasslands, either T. triandra in Victoria or T.
triandra and Austrostipa bigeniculata in the ACT (Kukolic 1994), but a few were dominated by the exotic perennial Phalaris
aquatica, while sites then dominated by Nassella spp. were found to no longer harbour the species (Hadden 1995). Kukolic
(1995) recorded pitfall trap captures in T. triandra grasslands with mixed native and exotic grasses and in areas more dominated
by exotic grasses at Yarramundi Reach, ACT. Hadden (1995) found that tussock cover >50% was usual at the majority of extant
sites and tussocks were considered important for shelter and as basking sites. D. impar utilises deep cracks in clay soils for
shelter, breeding and refuge, and surface rocks may be similarly used, but are not a necessary habitat component (Hadden 1995).
Fire was considered an unknown risk, while livestock grazing was considered acceptable since it occurred on nearly half the
known extant sites (Hadden 1995). Kukolic (1994) recommended that fire not be used to manage the habitat, mentioning finds of
dead individuals at Derrimut, Victoria, after control burns. Webster et al. (2003) noted that fires in spring represented a clear risk
to Victorian populations because soil cracks were seasonally unavailable. Weed invasion was listed as one of numerous threats to
its habitat (Webster et al. 2003). O’Shea (2005) found that the population at Iramoo Grassland, Victoria, was present in areas
dominated by N. neesiana and N. trichotoma as well as T. triandra areas, and persisted well in 0.5 ha areas that were deliberately
burnt. She argued that grassland structure (presence of perennial tussocks) rather than floristic criteria determined suitable
habitat.
Spiders, larval Lepidoptera, Black Field Crickets Teleogryllus commodus (Walker) (Orthoptera: Gryllidae) and cockroaches
(Blattodea) are the most frequently recorded prey items (O’Shea 2005). Coulson (1990) reported that the majority of faecal
pellets obtained from individuals at Derrimut Grassland, Vic., from mid January to early February contained unidentified larval
Noctuidae (Lepidoptera) and T. triandra fragments which were presumed to have been larval gut contents. Faecal pellets studies
by Wainer (1992) indicated prey 10-30 mm in length including locusts (Acrididae), an earwig, an ant, adult moths, as well as
items already mentioned. Invertebrates common in the habitat that were not eaten included millipedes, slaters, slugs, bugs
(Hemiptera) and beetles (Coleoptera). He also found unidentified grass seeds in the scats. Kutt et al. (1998) reported that nocutid
larvae consistuted a high proportion of the diet from November to January and crickets were predominant from December to
February, corresponding with the abundance of these taxa. The lizard appears to have a flexible foraging strategy with seasonal
food preferences, and forages in the daytime. Brumation takes place in the soil from late March or April to September (O’Shea
2005).
Victoria’s largest documented and best studied population (an estimated 600 individuals) is in the Iramoo Grassland Reserve,
Cairnlea. O’Shea (1997) provided preliminary details of alternative detection and trapping techniques for the lizard. O’Shea
(2005) found that the population at Iramoo was present in areas dominated by either T. triandra or N. neesiana and N.
trichotoma, however the exotic habitat was contiguous with the native habitat. Small scale (0.5 ha) summer and autumn fires
interspersed in larger areas of unburnt habitat appeared to have little effect on population size and structure or habitat quality.
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