Scientists capture rare footage of mother skink fighting a deadly brown snake to protect her babies



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Gregory Watson, University of the Sunshine Coast and Jolanta Watson, University of the Sunshine Coast

Unlike many mammals and birds, most reptiles show little sign of being caring parents. But our new research shows one lizard species may be more doting parents than we thought – the adults risking their own safety to protect their babies.

We used cameras in the Snowy Mountains of New South Wales to study the Cunningham’s skink. We were surprised to record evidence of the lizards actively defending their newborn offspring against formidable predators. Our findings are outlined in a paper released today.

Most startlingly, we recorded a mother skink aggressively attacking a large, deadly brown snake while her babies watched on. We also witnessed 12 incidents of skinks chasing magpies away from their young.

We originally set out to record how species such as skinks will cope with climate change. But this evolved into a study of the fascinating and surprising social bonds between lizard offspring and their parents.

Adult and young skinks sun-baking together
Sun-loving skinks live together in social groups.
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What is the Cunningham’s skink?

The Cunningham’s skink (Egernia cunninghami) is a large, sun-loving, spiny lizard native to southeast Australia. It’s named after Alan Cunningham, an explorer who collected the first specimen in the Blue Mountains.

The skinks are active during the day. They feed on invertebrates such as insects, snails and slugs, as well as vegetation.

The Cunningham’s skink lives in social groups – a behaviour very rare among lizards and reptiles. In these groups, mothers give birth to live young (rather than eggs) then live alongside their kids, sometimes for several years.

The species has strength in numbers – living in a group makes it easier to spot threats, which helps the group survive.

Adult and young skinks sun-baking together
Thew offspring of Cunningham’s skinks can stay with the parents for several years.

The mother of all discoveries

Using video and thermal imaging, we observed the skinks on 32 days over three years.

Among reptiles, evidence of parental protection in their natural environment has been rare and typically anecdotal. We witnessed four birthing sessions, and then monitored skink encounters in the presence of their offspring.




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Videoing nature can be tricky. Often, the action takes place away from where you’ve directed your camera. So when we saw a snake, it was a scramble to get a free video camera and start recording.

We witnessed two separate encounters with an eastern brown snake. The first involved the snake sneaking up on six-day-old skinks basking in the sun (see footage below). We recorded the mother running towards the predator and biting it for several seconds. The snake writhes around before the mother releases her grip and returns unharmed to her young.

The following year, we encountered two adult skinks attacking another eastern brown snake in bushes. Juvenile skinks were nearby. The skinks bit tight to the snake’s body, and the snake dragged them for more than 15 metres before the skinks released their grip.

Snakes were not the only predator vanquished by the protective skink parents – Cunningham’s skinks regularly chased magpies away from their young. We observed 12 encounters between skinks and magpies. In each case, an adult skink aggressively chased and/or attacked the magpie after the bird came close to the group.

Thermal camera image showing the mother skink attacking the snake while her babies watch on
Thermal camera image showing the mother skink attacking the snake while her babies watch on.

What does this all mean?

Some animals rarely interact with others of the same species, even their offspring. In fact, available data suggests infanticide – where mature animals kill young offspring of the same species – can occur among some skink species.

We saw no such behaviour among the Cunningham’s skink, or aggression towards each other.

While the aggression of the adult skinks towards predators took place in the presence of young, the adults may have been exhibiting self-defence or territorial behaviour. Regardless, the attacks on predators in the presence of newborns does reflect parental care, either directly or indirectly. Our future field excursions will hopefully shed more light on this.

Understanding the factors that bring parents and offspring together, and keep them together, is important in our broader understanding of social evolution – that is, how social interactions of species arise, change and are maintained.

It will also help us understand how animals cooperating with and caring for each other can benefit both the individual, and the whole.




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The Conversation


Gregory Watson, Senior Lecturer, Science, University of the Sunshine Coast and Jolanta Watson, Lecturer in Science, University of the Sunshine Coast

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Like alchemists with killer precision, brown snakes make different venoms across their lifetime


Timothy N. W. Jackson, University of Melbourne

It’s spring in Australia and that means reptiles are starting to move about again. Including snakes.

The venom of the eastern brown snake (Pseudonaja textilis) is, drop for drop, one of the most potent of any venoms tested on laboratory mice.

Venoms work by targeting the bitten animal with deadly chemicals. And our recent research shows toxins in the venom of eastern brown snakes change as the snakes grow from juveniles to adults. It’s the first example of a significant age-related change in venom from an Australian snake.

It’s a beautiful example of evolutionary adaption, in which the chemistry of the snake’s venom appears to change in parallel with its diet.


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What is snake venom?

Venoms are typically a mixture of different toxins, each of which attacks the system of a potential prey animal or predator in a different way.

Sometimes toxins work together, each making the other more powerful, and sometimes they work completely independently, engaging in chemical warfare on multiple fronts.

Brown snake venom contains many toxins, but there is one toxin above all others that is responsible for the life-threatening effects of bites to humans. This toxin is a “haemotoxin”, which means it attacks the blood.

The haemotoxin starts clotting the blood at an extremely elevated rate, using up all of the coagulation factors, which clot the blood under normal circumstances. When all these are used up, the victim is at risk of bleeding to death.

In the worst case scenario this toxin, perhaps working with others, gives the system such a shock that people collapse within a short period of time following the bite. In this situation, immediate CPR can be the difference between life and death.

Why venom evolved

Venom is a tool that has evolved in snakes to help them secure a meal: it gives them a chance of overpowering animals that would otherwise be very difficult for them to subdue. Venom and its toxins are therefore “designed” (by evolution) to mess up the normal operations of a prey animal’s body.


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The best toxins for this purpose may differ according to the specific type of prey animal (e.g. mammal or reptile), or the condition of that prey animal (e.g. whether it is active or inactive) when the snake finds it. As a result, we often find snakes that feed upon different types of animals have different toxins in their venoms.

This starts to get really interesting when you consider brown snakes, because adult brown snakes seem to have quite different diets from baby brown snakes.

Testing a venom hypothesis

Age-related shifts in venom chemistry have already been demonstrated for the venoms of a few species of pit vipers from the Americas, but not for anything even remotely related to Australian brown snakes.

This wasn’t because people hadn’t looked – several species of Australian snake had been investigated, but no evidence of a significant age-related change in venom had been found for any of them. This made sense to me, because none of those snakes dramatically change their diets throughout their lives.

Brown snakes are special – as far as we know the juveniles eat lizards almost exclusively, whereas the adults are generalists that eat a lot of mammals.

Baby snake venom is different

When we compared venom in adult and baby brown snakes, we did indeed find them to be different. Baby brown snake venom seems to entirely lack haemotoxins: instead, it’s almost exclusively composed of neurotoxins – toxins that attack nerve junctions.

What this suggests is that the haemotoxins that are so dangerous to humans (and lab mice) aren’t very effective against the lizards that baby brown snakes eat. We can make this dietary link with a degree of confidence because many other Australian snakes that feed exclusively on lizards have similar venom – no haemotoxins, only neurotoxins.


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We don’t yet know what this means from a clinical perspective. It may be that baby brown snake venom is less dangerous to humans than adult brown snake venom, but the opposite might also be true – brown snake antivenom might be less effective against the venom of the babies.

There has been at least one fatal bite from a very small brown snake in Australia, so they must be treated with respect at any age.

The ConversationAs always, the best policy for snakes is to leave them alone and let them go about their business, and to teach children to do the same – snakes want no more to do with us than we want with them.

Timothy N. W. Jackson, Postdoctoral Research Fellow, Australian Venom Research Unit, University of Melbourne

This article was originally published on The Conversation. Read the original article.