The truth behind this year's snake season – The Advocate

Australia’s reputation as home to some of the world’s deadliest animals is as ubiquitous as its connection to beer and barbecues. But is it based on reality?
The truth, particularly when it comes to snakes, is much more complex, Melbourne University researcher Timothy Jackson says.
“We certainly don’t have any of the world’s most dangerous snakes (by death rates), because in Australia we have, say, three snakebite deaths a year,” Dr Jackson told AAP.
“But worldwide there are over 100,000 snakebite deaths per year.”
However, Australia’s reputation is not entirely unjustified, the toxinologist noted.
“Some of these snakes have incredibly toxic venom.”
Saturday, November 19, was Australia’s first Venomous Bites and Stings day, which aims to raise awareness about Australia’s venomous creatures and the importance of applying correct first-aid to victims of toxic bites and stings.
Australia is the only continent in the world where venomous snake species, of which there are 20, outnumber the roughly 120 non-venomous snake species.
But they haven’t always been here.
The elapid family of snakes – which worldwide include cobras and mambas and in Australia include eastern browns, tiger snakes and taipans – came to Australia from Asia via landbridges and Melanesia around 20 million years ago.
The elapidae thrived in their new lands, which at that time hosted only a few species of pythons and blind snakes for competition.
“And so this particular family just took advantage of the absence of other snakes and became our most diverse family,” Dr Jackson said.
“So we now have over 100 species on land from that family.”
Some studies indicate the snakes that arrived here were amphibious, and their success evolving on and around the Australian continent is reflected in sea snake species further north.
“We have another radiation of marine snakes, the so-called true sea snakes, that comes out from within the Australian radiation of the elapids.
“So most of the world’s sea snakes, even though they’ve gone and spread back through Asia, are actually Australian snakes.”
The myriad evolutionary factors behind Australian snakes’ potent venoms are hard to pin down, but one hint lies in the bite of the world’s most venomous snake, the inland taipan.
“It’s a boom or bust animal,” Dr Jackson said.
“It lives in a semi-arid environment. It goes for long periods of time without much food around.”
When the weather is right, inland taipans start breeding in large numbers and gorge themselves on rodents.
“They want to be able to kill these rodents really rapidly, subdue these rodents really rapidly and also only use a small amount of venom … they don’t want to use it all in one go.
“They want to be ready to, perhaps in the next week, feed on a dozen rodents or something like that during that time of year when the rodents are plentiful. They want to fatten themselves up.”
Dr Jackson said it was difficult to objectively qualify venom potency since studies were only performed on lab mice.
“The snake continually is evolving this more toxic venom, the natural prey is evolving the degree of resistance, and we don’t capture any of that biological reality,” he said.
Dr Jackson said he had seen about 40 tiger snakes in his Melbourne suburb this spring, but admitted it was difficult to pin this down to an increase in snake populations.
“It’s obviously super wet in a lot of parts of the country.”
Water was spreading prey like frogs out further, and tiger snakes were following their stomachs, while floods were giving snakes less real estate to hide, rest or sun themselves.
“Generally speaking, seeing more snakes doesn’t mean there are more snakes. It just means that they’re more conspicuous,” Dr Jackson said.
Professor Bill Nimorakiotakis, a retrieval specialist working in remote areas with the Royal Flying Doctors Service, said the season so far had been significant in terms of snake bites.
“I’ve certainly, on a clinical perspective, been seeing more people present with snake bite, including those patients being in-venom,” Dr Nimorakiotakis told AAP.
Interestingly though, more than 50 per cent of snake bites were actually “dry bites”, venomless bites designed to ward off larger threats.
“It’s more a bite to tell him to p*** off rather than I’m going to eat you sort of type of thing.”
“Snakes consume or need to consume a lot of food to produce that energy to make the venom.”
Dr Nimorakiotakis said in the case of a snake bite, immobilisation and a pressure bandage around the bite site should be applied until the patient gets to hospital.
“A good elastic bandage, start at the fingertips, exposing the fingertip so we make sure that there’s circulation going to the fingertips and you go as high as you can, and the next thing is to immobilise it,” he said.
Dr Nimorakiotakis said Australia had the best treatment protocols and antivenoms in the world, having begun producing antivenoms in the 1930s – the key was getting patients safely to hospital.
“If someone collapses, what they should be doing is CPR,” he said.
“We know for a fact, those patients that have been bitten by a snake who have collapsed and have had early CPR do okay, so it’s a transient thing.”
It is unknown why such collapses were transient.
“We need to get them to a health facility where we can give them antivenom but we need to keep them alive to get to that facility.”
For more information on up-do-date first aid techniques and education materials, go to https://www.bitesandstings.com.au/
Australian Associated Press
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