iHerp Australia Issue 7 | Page 4

All that glitters is not The golden Tiger Snake of Tasmania. Simon Fearn reveals that there is real gold in ‘them thar hills’, but warns potential prospectors to be wary of forgeries. Tasmania’s cool and highly variable climate has undoubtedly played a significant role in selection for dorsal colouration in Tiger Snakes (Notechis scutatus).These large snakes thrive under conditions which must be close to the lower limits of their thermal tolerances, particularly in relation to reproduction. There is therefore a general overall tendency for melanism throughout Tasmania, but especially in cool, high rainfall areas of the west and southwest, as well as the extensive central plateau where it can snow at any time of the year. Banding on Tasmanian specimens is also generally less defined than many mainland Tiger Snakes, and band width is typically reduced to between half and one and a half scales. A significant proportion of predominantly black specimens display banding that ranges from bold contrasts of brown, orange, yellow or white to barely discernible cross bands that can only be perceived in strong sunlight. On many melanotic specimens banding is reduced to yellow or white edging on the first few rows of dorsolateral scales. Completely melanotic Tiger Snakes can occur anywhere in Tasmania, and although in the minority, are more common in the Central Highlands. In warmer, low- lying and particularly coastal habitats in eastern Tasmania a bewildering array of colour variations can be encountered; from rich yellows to shades of tan, brown, grey, silver and some that appear almost greenish under appropriate lighting. The vast majority of these animals display darker cross band- ing, but in the forests of the Great Western Tiers, in the foothills of the central plateau, the author has Left: wild yellow Tiger Snake exhibiting prominent banding from Railton. Photo by M. Wapstra. Above right: ‘washed out’ Tiger Snakes raised without UV light. These are from the late Phillip Goss's collection. The lower snake would be predominately greyish-black with indistinct yellow bands if raised outdoors. Photo by S. Fearn. Right: this large Tiger Snake has been raised indoors and would be horribly sunburnt if put outdoors in summer. Photo by S. Fearn.