Hemiaspis damelii
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Elapidae
Genus: Hemiaspis
Species:
H. damelii
Binomial name
Hemiaspis damelii
(Günther, 1876) [2]
Synonyms[3][4]
  • Hoplocephalus damelii
    Günther, 1876
  • Denisonia dæmelii
    — Boulenger, 1896
  • Drepanodontis daemelii
    — Worrell, 1961
  • Hemiaspis damelii
    — Cogger, 1983

Hemiaspis damelii is a species of venomous snake in the family Elapidae. It is a relatively small species of elapid with a mean snout-vent length (SVL) of 42.6 to 60 cm (16.8 to 23.6 in).[5] The species is endemic to eastern Australia and is most commonly found across central inland New South Wales through to the interior of south-eastern Queensland.[5][6][7] Common names for this species include ngabi, grey snake and Dämel's Snake. The specific name, damelii, is in honor of German entomologist Edward Dämel, who collected Australian specimens for Museum Godeffroy.[8]

Description

H. damelii is a relatively small snake with an average snout-to-vent length (SVL) of 50 centimetres (20 inches).[6] Minor size differences occur between sexes, with the males averaging a slightly larger size than females.[9] It is olive to grey dorsally, and white to yellowish white ventrally, often flecked with dark grey.[9][5][7] In some grey snakes, each scale may be tipped with black anteriorly, particularly on the flanks.[7]

It has smooth dorsal scales which are in 17 rows at mid-body, 140-170 ventral scales, and 35-50 subcaudals which are single (undivided).[7] This species also has a paired (divided) anal scale.[7] Juvenile grey snakes have a distinctive black head which fades or sometimes completely disappears as the snake matures, occurring from the top of the head to the second scale row behind the parietals.[7]

Distribution and habitat

The distribution and ecology of H. damelii is poorly known.[5] Existing records of the grey snake are most commonly found in south-eastern Queensland and north-central New South Wales, however small populations have also been found to occur in north-eastern South Australia and south-western New South Wales.[5] It tends to favour dry sclerophyll forests and woodlands on clay soils where water bodies or gullies are present. It shelters under rocks, logs and other debris, as well as in cracks in soil.[10]

Reproduction and life cycle

The breeding period for H. damelii occurs from January to March. During Spring (September-October) adult females' ovarian follicles increase in size following ovulation in preparation of the breeding season.[9] H. damelii has a relatively high fecundity, partly due to its large maternal snout-vent length (SVL), which has been found to significantly correlate with litter size.[10] Litter size can range from 4-16 live young which are born fully formed[10] (viviparous). The newborns take an average of 12 months to mature after birth.[10]

Diet

The diet of H. damelii consists predominately of terrestrial anurans.[9] It has also been found to consume some scincid lizards, however this is quite rare.[9]

Behaviour

H. damelii is active during the night, beginning to move around sunset and remaining active for 1-2 hours after, using this time to hunt and feed.[9]

Venom and symptoms

The venom of H. damelii is fairly mild and is unlikely to cause fatalities in humans; however, a bite from a larger specimen may be very painful.[7] The venom contains procoagulants and causes local pain and swelling.[11]

Conservation status and threats

In Queensland, H. damelii is listed as an endangered species under the Nature Conservation Act, 1992.[5] It is also listed as endangered on the IUCN Red List of Threatened Species due to population decline.[5] The key processes threatening H. damelii include the impacts of feral animals such as cats and foxes via predation, cane toads through ingestion and feral pigs through habitat destruction and competition for food resources.[10] Increasing pasture improvement and cultivation are also destroying habitat through the disruption of soil structure in cracking clay soils.[10] Changes to waterways and the hydrological cycle are also impacting grey snakes which rely on these floodplains and water sources.[10]

Recent floods in NSW have helped researchers find 30 individual snakes. The venomous snake has only been seen a handful of times in the past 65 years. [12]

References

  1. ↑ Vanderduys, E.; Wilson, S.; Hobson, R.; Venz, M.; Sanderson, C. (2017). "Hemiaspis damelii ". IUCN Red List of Threatened Species. 2017: e.T102709908A102709925. doi:10.2305/IUCN.UK.2017-3.RLTS.T102709908A102709925.en. Retrieved 20 November 2021.
  2. ↑ "Hemiaspis damelii (Günther, 1876) - Grey Snake". Atlas of Living Australia. Retrieved 2 August 2014.
  3. ↑ Boulenger GA (1896). Catalogue of the Snakes in the British Museum (Natural History). Volume III., Containing the Colubridæ (Opisthoglyphæ and Proteroglyphæ) ... London: Trustees of the British Museum (Natural History). (Taylor and Francis, printers). xiv + 727 pp. + Plates I-XXV. (Denisonia dæmelii, p. 339 + Plate XVIII, figure 3).
  4. ↑ Species Hemiaspis damelii at The Reptile Database www.reptile-database.org.
  5. 1 2 3 4 5 6 7 Michael, Damian R.; Bourke, Gaye; Paris, Dena; Wassens, Skye (2020). "A range extension for the endangered Grey Snake Hemiaspis damelii (Günther 1876) in the Murrumbidgee catchment, southern NSW". Australian Zoologist. 40 (4): 652–655. doi:10.7882/AZ.2020.008. S2CID 212865650 – via Royal Zoological Society of New South Wales.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  6. 1 2 Australian Reptile Online Database (2019). "Grey snake Hemiaspis damelii ". Australian Reptile Online Database (AROD). Retrieved 25 October 2020.
  7. 1 2 3 4 5 6 7 Cogger, Harold (March 2014). Reptiles and Amphibians of Australia (7 ed.). Collingwood, Victoria: CSIRO. pp. 1385–1386. Retrieved 22 October 2020.
  8. ↑ Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). The Eponym Dictionary of Reptiles. Baltimore: Johns Hopkins University Press. xiii + 296 pp. ISBN 978-1-4214-0135-5. (Hemiaspis damelii, p. 64).
  9. 1 2 3 4 5 6 Shine, Richard (March 1987). "Food habits and reproductive biology of Australian snakes of the genus Hemiaspis (Elapidae)". Journal of Herpetology. 21 (1): 71–74. doi:10.2307/1564381. JSTOR 1564381. Retrieved 22 October 2020.
  10. 1 2 3 4 5 6 7 "Grey snake". Queensland Government Department of Environment and Science. 2019. Retrieved 25 October 2020.
  11. ↑ "Hemiaspis damelii ". Clinical Toxinology Resources. The University of Adelaide. www.toxinology.com.
  12. ↑ "Night research helps scale up estimates of grey snake population in NSW floodplains". ABC. Retrieved 2022-04-09.

Further reading

  • Günther A (1876). "Descriptions of new species of Reptiles from Australia collected by Hr. Dämel for the Godeffroy Museum". Journal des Museum Godeffroy 5: 45-47. (Hoplocephalus damelii, new species, p. 46).
  • Wilson S, Swan G (2013) A Complete Guide to Reptiles of Australia, Fourth Edition. Sydney: New Holland Publishers. 522 pp. ISBN 978-1921517280.


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