Copperheads, Austrelaps Worrell, 1963

Australian copperhead snakes

Distribution map of Copperhead Snakes
Distribution map of Copperhead Snakes

The copperheads are inoffensive elapids from southern Australia. They are cool-climate snakes and A. ramsayi (highlands copperhead), the species with the northernmost distribution, occurs exclusively in upland areas. A. superbus (lowlands copperhead), on the other hand, is one of only three species of snake that occurs in Tasmania (the other two are also elapids). Although all three species of copperhead should be considered potentially dangerous, these snakes are reluctant to bite without extreme provocation and human bite accidents have been rare.

Distribution: South-eastern mainland Australia (New South Wales, Victoria and South Australia), Tasmania and offshore islands.

Distinguishing characteristics: Body slender but muscular, scales smooth in 15-17 smooth rows at midbody, lowest lateral rows enlarged, subcaudal scales and cloacal plate entire, patterning unicolour or with lowest lateral scale row paler, eyes moderately large with round pupils.

Australian species: Three, all endemic.

Habitat: Copperheads are typically found near water in grasslands, swamps and marshes, forests and agricultural areas, lowland and highland.

Activity: Either nocturnal or diurnal, often active in cool weather.

Diet: Copperheads feed almost exclusively upon lizards and frogs, but like many elapids they are opportunists and may occasionally feed upon snakes and reptile eggs. Very infrequently, they may feed upon mammals and invertebrates.

Reproduction: All three species are ovoviviparous, producing an average of 15 neonates.

Venom: The venom of all three species of copperhead is neurotoxic and contains both post- and pre-synaptic neurotoxins. At least one human bite victim has suffered from life-threatening systemic neurotoxicity as the result of copperhead envenomation (this victim recovered following the administration of antivenom). The venom of these snakes also contains myotoxins and haemotoxins, although clinically significant myotoxicity or blood disturbances have not been documented.

The recommended treatment for Austrelaps envenomation is Seqirus (bioCSL) Tiger Snake Antivenom (TSAV).

Austrelaps labialis (Jan, 1859)

Pygmy Copperhead

Distribution: SA (southern Mt Lofty Ranges).

Islands: Kangaroo Is., SA.

Length: 0.8-1.2 m

Distinguishing characteristics: Dorsal scales smooth, in 15, rarely 17 rows at midbody, lowest lateral rows enlarged; ventrals 130-155; cloacal plate entire; subcaudals 35-55, all single; six supralabials; temporolabial scale not or only slightly contacting lower postocular scale.

Colouration & patterning: Dorsum dark brown, olive-brown, to black or dark grey, paler in juveniles, with black bars on the pale lips; venter cream to grey.

Habitat: Swamps and marshes, creeks and stream-sides, grasslands, high elevation forests, woodlands near water, sand dunes, and agricultural habitats.

Activity: Nocturnal or diurnal, active even in cool weather.

Diet: Predominantly ectothermic prey: lizards and frogs.

Reproduction: Ovoviviparous, with litters of 7-15 neonates.

Austrelaps ramsayi (Krefft, 1864)

Highlands Copperhead

Distribution: NSW (east & southeast); Vic (extreme east).

Length: 1.3-1.7 m

Distinguishing characteristics: Dorsal scales smooth, in 15, rarely 17 rows at midbody, lowest lateral rows enlarged; ventrals 150-170; cloacal plate entire; subcaudals 35-55, all single; six supralabials; temporolabial scale broadly contacting lower postocular scale.

Colouration & patterning: Dorsum ranging from yellow-brown, to reddish-brown or dark brown, even black, the enlarged lateral scales being yellow, cream or red, lips strongly barred, juveniles often paler than adults; venter cream to grey.

Habitat: Swamps, marshes, riverbanks and cool montane heathland.

Activity: Nocturnal or diurnal, active even in cool weather.

Diet: Predominantly ectothermic prey: lizards, and frogs, occasionally snakes.

Reproduction: Ovoviviparous, with litters of 9-31, average 17, neonates.

photo of Austrelaps ramsayi, the Highlands Copperhead
Austrelaps ramsayi, the Highlands Copperhead (Photo - Stephen Zozaya)

Austrelaps superbus (G√ľnther, 1858)

Lowlands Copperhead

Distribution: NSW (extreme southeast); SA (extreme southeast); Tas (north & centre); Vic (south & east).

Islands: Bass Strait: Furneaux Group (Flinders, Cape Barron, & Clarke Is.) & New Year Group (King & Hunter Is.), Tas.

Length: 1.3-1.7 m (largest specimens on King Island, Bass Strait)

Distinguishing characteristics: Dorsal scales smooth, in 15, rarely 17 rows at midbody, lowest lateral rows enlarged; ventrals 140-165; cloacal plate entire; subcaudals 35-55, all single; six supralabials; temporolabial scale not or only slightly contacting lower postocular scale.

Colouration & patterning: Dorsum dark brown, reddish-brown, black or grey, enlarged lateral scales yellow, red or cream, lips weakly barred; venter cream or grey.

Habitat: Lowland swamps, marshes, sand dunes with tussock grass, heathlands woodlands and sclerophyll forests.

Activity: Nocturnal or diurnal, active even in cool weather.

Diet: Predominantly ectothermic prey: lizards, and frogs, occasionally snakes or small mammals. In Tasmania, where lowlands copperheads occur sympatrically (in the same habitat) as tiger snakes, the copperheads feed almost exclusively on ectothermic prey, whereas tiger snakes have a far more diverse diet, including large quantities of birds and mammals.

Reproduction: Ovoviviparous, with litters averaging 15 neonates.