iHerp Australia Issue 6 - Page 23

‘Chappell Island is literally moving with big Tiger Snakes.’ snakes are meagre and the summer is short. Judging by the number of adults with stumpy tails, I suspect the gulls are attacking them, and of course if they happen to pick up a snake that is small enough, it goes straight down the gob. In the past there were also feral cats on the island, which contributed to predation on young snakes, but according to the rangers, after a successful trapping program there is only one left. In addition, Tiger Snakes are known to be cannibalistic, so the juveniles avoid the muttonbird rookeries where most of the adults reside, and instead mainly inhabit areas of grassy tussock and large shrubs, which serve as refuge when danger approaches. So, whilst the adult Tiger Snakes have no predators, the young ones are constantly under the pump. Many of the adult snakes have scarred necks from ticks, which doesn’t add to their good looks, but they don’t seem to be infested to the point where they can not function. Apart from a small spring on the southern side, there is no permanent water on the island, so the snakes don’t have the opportunity to soak themselves to get rid of the ticks. No water means there are no frogs, and hence likewise there are no copperheads on Chappell Island. The Tiger Snakes feed largely on muttonbird chicks during the breeding season, but once the chicks are too big it’s the end of the feast. Rats and mice provide little supplement to the snake’s menu; it’s the fatty, oily and smelly chicks that constitute the main course. The window of opportunity only lasts about six weeks in the summer months before the chicks are too big for the snakes to swallow.