Snake of the Week – Desert Death Adder Acanthophis pyrrhus

Desert Death Adder Pic. Gloria Morales

The Desert Death Adder, Acanthophis pyrrhus is found throughout the ‘true’ deserts of Australia and is (relatively) common here on the fringes of the Southern Tanami desert. We mainly see this snake in or near to the Spinifex country near rocky ridges and creeklines. And with the good rains we’ve had over the past month or so all of the snakes and lizards are more active and we fully expect to see more Death Adders and other snakes around.

We saw this (above) beautiful snake earlier this year in a creekbed in the borefield 15 or so kilometres west of town where the dogs get a run on most days. Last Sunday afternoon one of its relatives killed one of our favourite little dogs, Boot-boots.

We’d taken the dogs out for a walk and a swim in one of the waterholes filled by recent rain. As usual the dogs spent a lot of time chasing the many small lizards that scuttle at considerable speed between the spinifex clumps that dominate the base of the valleys between the rocky ridges.

The dogs spend a lot of their time out bush time scurrying after lizards between the large and incredibly spikey spinifex clumps and it is not uncommon to see a bunch of five or more dogs head-down and arse-up around a clump of spinifex while the lizard the target of their attentions sneaks off out of sight.

But when there is a snake around the dogs behave quite differently. The older dogs will give a particular yelping bark (the ’snake-is-here’ bark?) when they bail up or are on the track of a snake. Usually you can pick up those calls or different behaviours pretty quickly, but when we were out with the dogs one day earlier this week we were distracted for a few minutes before we realised that a lot of the dogs were paying a lot of attention to a spot at the base of an Acacia bush.

We got up and chased the dogs away from the bush and had a closer look at the tangle of branches and spinifex in the area and failed to spot the object of the dogs’ rapt attention at first but after a few minutes searching found a small Desert Death Adder, perhaps 40cm long, curled up in the spines of a large patch of spinifex. We’d shooed the dogs away and didn’t notice that any of them appeared to have been bitten.

An hour of so later we left for home. All of the dogs seemed fine as they clambered into the car. When we arrived home they piled out of the car with their usual vigour – except for Boot-boots, who was lying on the floor of the car, breathing heavily and in obvious pain. We took him inside and within a half-hour he was dead.

As the Clinical Toxicology Resources page at the University of Adelaide adivises:

“Overall death adder venom is highly potent, though slightly less potent than common brown snake venom, tiger snake venom and taipan venom.

Death adder venom contains potent postsynaptic neurotoxins (toxins in venom that cause paralysis or muscle weakness), but no presynaptic neurotoxins.

Death adder venom does not contain potent procoagulants (toxins in venom that interfere with blood clotting, causing consumption of the clotting protein, fibrinogen; this causes defibrination, with non-clottable blood, putting victims at risk of major bleeding).

No renal (kidney) toxins have so far been isolated from death adder snake venoms, and renal failure (kidney failure) is not a common effect of death adder snake snakebites in humans, even in cases where there is significant envenoming (envenomation).

Death adder venom does contain myotoxins that theoretically could cause myolysis (rhabdomyolysis, muscle damage), but there is no evidence this occurs in humans bitten by these snakes.

Death adder venom causes generally minor local effects at the snakebite site, such as mild swelling and pain and does not contain necrotoxins, and local tissue necrosis does not occur.”

Postscript – very soon after posting…forget to add the good news (?) is that on the weekend we were out at the water hole and again found the dogs head-down around a clump of spinifex. Sure enough, after shooing them away we found the Death Adder but then lost it in the grass clumps – thinking that it had gone down a hole. We burned some of the spinifex and the snake was soon on the move – after about 15 minutes of chasing the snake through the clumps of grass and selectively burning we were able to get it into a bag and relocate it a few kilometres away – and well clear of where we normally walk…and no more dogs were bitten.