Hazards in the Wet Tropics No

Tropical Topics A n i n t e r p r e t i v e n e w s l e t t e r f o r t h e t o u r i s m i n d u s t r y Hazards in the wet tropics No. 31 November 1995 Small is significant Notes from the One of the first questions commonly asked by visitors to the wet tropics is about dangerous snakes. However, one of the most dangerous animals in the wet Editor tropics — the cause of at least 20 deaths in Australia in the first half of this This issue of Tropical Topics looks at century — is one of which few people are aware and which is so small its a variety of the things which may bite, approach is almost never noticed. It is the Australian paralysis tick (Ixodes sting, kick, suck or poison visitors to holocyclus) also known as the scrub tick. the wet tropics. Many people believe that the rainforest is full of snakes and Ticks are essentially large mites which bushwalking all members of the group other animals just waiting for a chance need to feed on blood and are should be checked for the following to attack them. In fact, they are most attracted to their hosts by movement six days for signs of ticks — usually a unlikely to be harmed, especially if and by the carbon dioxide exhaled by minor irritation and lump. they keep to the tracks and do not try mammals. Dropping on to their victims to sample ‘bush tucker’. from grass or leaves, they quickly find If one is found a dab of petrol, lighter a dark moist spot such as the upper fluid, kerosene, turpentine or Probably the greatest dangers for thighs, armpits, behind ears or on the insecticide may cause the animal to visitors to the wet tropics are not in scalp where they attach themselves drop off. Otherwise, grasp the tick as the rainforest but in nearby water. Hot and begin to feed. A female needs near to the person’s skin as possible and tired from their walks they may three feeds of blood during its life but and pull it off, taking care not to put themselves at risk on slippery it is usually the third feed of the large squeeze the body which might then rocks and in fast-flowing or croc- adult female which causes trouble. inject more saliva. If the mouthparts inhabited rivers. Many will be only (The adult male feeds on female ticks.) remain, they can be flicked out with a too ready to splash into the summer sharp blade, but there is no need to sea, unaware of the danger posed by From time to time, as the tick feeds, it cut the skin. box jellyfish. It is important that guides injects unwanted fluid from the blood and others in the tourism industry back into the host’s body, along with Reaction to the toxin wears off slowly warn visitors, particularly those from its own saliva. This saliva contains a (even increasing for a while following overseas, of these dangers. powerful toxin and the output removal). Happily, due to awareness of increases as the tick’s body enlarges. the problem and the availability of an Some terminology antitoxin, deaths from ticks are now A venomous animal uses a bite or Small children begin to show the very rare. sting to introduce a toxin into another effects of the toxin after about three animal. A poisonous animal, such as days when their walking tends to a pufferfish or toad, contains toxins become unsteady. This muscle which may be absorbed if the animal paralysis spreads to their arms and is eaten. The term toxic covers both. then, if no help is given, to their chest muscles, at which stage they may die Strictly speaking, anti-venom for from respiratory failure. The snakes is termed antivenene and for devastating effect of its saliva on spiders antivenin. For the sake of some hosts is of no obvious use to the simplicity all are referred to as anti- tick and seems to be purely a quirk of venom in this newsletter. nature. Its normal native host, the bandicoot, is immune. Tour operators may wish to laminate page 7 and make it available in coaches, It is important to be aware of the offices and so on to encourage potential impact of paralysis ticks, An adult tick is at first oval, flat, environmentally-friendly behaviour. especially on children (and pets) and yellowish and the size of a match particularly during the peak season, head. As it feeds it darkens and swells from June to December. After to the size of a pea (above). Venomous snakes The bad news and the good news There are approximately 140 species of land snake in The good news is that Australian snakes are responsible for Australia. Some 70 percent of them are venomous, making relatively few human deaths. In fact, statistically, you are as Australia possibly the only country in the world where likely to die from a snake bite in France as you are in venomous snakes outnumber non-venomous species. Australia! Most dangerous Australian snakes are shy and However, of these only about 20 species (all in the elapid unaggressive. Also, the availability of anti-venom and the family) are considered dangerously venomous to humans. A adoption of effective first-aid measures have undoubtedly further dozen or so may be dangerous to children. saved many lives in recent decades. Dangerous snakes in the wet tropics Avoiding trouble Happily, most of the snakes which visitors to wet tropics rainforests are likely Venom is a modified saliva used to to see are non-venomous pythons and tree snakes. (Pythons are, however, incapacitate prey. It allows the capable of delivering nasty, if non-venomous, bites when antagonised.) snake to target a range of animals Nevertheless, some dangerous snakes inhabit the wet tropics. which would otherwise be too big to tackle. Venom also begins the Taipan (Oxyuranus scutellatus) reptiles. It is quick to retreat and if process of digestion and speeds it The taipan is fast and agile, with very cornered tends to make bluff attacks, up, important for cold-blooded long fangs (up to 13mm). In the past a preferring not to waste its venom. This animals whose stomach enzymes bite was invariably fatal. It is mainly an venom is not very toxic and fatalities could stop working if external inhabitant of tropical woodlands and are rare in adults, although it could be temperatures drop below critical cane fields, its liking for rats and mice dangerous to children. levels. The third function of venom bringing it into contact with humans. It is to act as a deterrent. is not naturally aggressive and will Eastern or common brown snake always prefer to retreat from a human (Pseudonaja textilis) A snake does not wish to bite but will attack ferociously if cornered. This snake is found in a variety of humans and waste venom on prey habitats and is common in open forest too large to consume. Most will Northern death adder (Acanthophis and cultivated land of the Tablelands. remove themselves if at all possible praelongus) When threatened it may rear up and and, even when cornered, will often bite aggressively, delivering one of the withhold venom when biting. The most potent snake venoms, albeit in golden rule is not to meddle with small quantities. Its liking for rats and snakes and wear boots and jeans mice brings it into contact with when in snake country. humans and it is a leading cause of serious snake bite in Queensland. First aid The most important action to take Rough-scaled snake (Tropidechis following a snake bite is to prevent carinatus) the poisons from moving into the Found close to water in moist forested general circulation. The venom country and often at high altitudes, initially spreads through tissues this snake is nervous and easily close to the bite and collects in Death adders prefer dry forest, provoked. Its venom is quite toxic and lymphatic vessels from which it grassland and sandy scrubland. Well- has caused human fatalities. Bush moves to the blood stream. The camouflaged, this snake lies in ambush walkers should be aware that this lymphatic vessels run very close to in the leaf litter waggling the worm-like snake often suns itself on rocks and the skin so an elastic bandage, or end of its tail to lure lizards, birds and knee-high bushes, especially after rain. clothing, wrapped firmly around the rodents within striking distance of its bitten limb can slow down the head. Unlike most snakes, it does not Small-eyed snake (Cryptophis progress of the venom. Since the move away when humans approach nigrescens) flow results from muscle movement and strikes swiftly with a potent This nocturnal snake lives in wooded a splint to immobilise the limb will venom when trodden on. areas including rainforests, feeding help. The old-fashioned methods of mainly on small reptiles. Bites can be cutting the wound and using Red-bellied black snake (Pseudechis painful and cause headaches. At least tourniquets are OUT! porphyriacus) one man has died as a result so it This snake is usually found around should be treated with caution. • Always carry an elastic bandage water and damp coastal forests where when in the bush. it feeds on aquatic animals and small • If bitten, do not panic or rush around. Move as little and as calmly as possible. • Do not try to kill or capture the snake which is then likely to cause more damage.

Load more