Curious Kids: What happens if a venomous snake bites another snake of the same species?



File 20170728 23784 v68xsb
Scientists usually use the word “venomous” rather than “poisonous” when they’re talking about snakes.
Flickr/Sirenz Lorraine, CC BY

Jamie Seymour, James Cook University

This is an article from Curious Kids, a series for children. The Conversation is asking kids to send in questions they’d like an expert to answer. All questions are welcome – serious, weird or wacky!


If a lethally poisonous snake bites another lethally poisonous snake of the same species does the bitten snake suffer healthwise or die? – Ella, age 10, Wagga Wagga.


Hi Ella,

That’s a great question.

If a venomous snake is bitten by another venomous snake of the same species, (for example during a fight or mating), then it will not be affected.

However, if a snake is bitten by a venomous snake of another species, it probably will be affected.

This is probably because snakes have evolved to be immune to venom from their own species, because bites from mates or rivals of the same species probably happen fairly often.

But a snake being regularly bitten by another snake from a different species? It’s unlikely that would happen very often, so snakes haven’t really had a chance to develop immunity to venom from other species.


Read more: Guam’s forests are being slowly killed off – by a snake


Scientists often collect venom from snakes to create anti-venoms.
Kalyan Varma/Wikimedia

Snakes can break down venom in the stomach

Many people believe that snakes are immune to their own venom so that they don’t get harmed when eating an animal it has just injected full of venom.

But in fact, they don’t need to be immune. Scientists have found that special digestive chemicals in the stomachs of most vertebrates (animals with backbones) break down snake venom very quickly. So the snake’s stomach can quickly deal with the venom in the animal it just ate before it has a chance to harm the snake.

People that have snakes as pets often see this. If one venomous snake bites a mouse and injects venom into it, for example, you can then feed that same dead mouse to another snake. The second snake won’t die.


Read more: Curious Kids: How do snakes make an ‘sssssss’ sound with their tongue poking out?


The eastern brown snake, which is found in Australia, is one of the most venomous snakes in the world.
Flickr/Justin Otto, CC BY

The difference between venom and poison

By the way, scientists usually use the word “venomous” rather than “poisonous” when they’re talking about snakes. Many people often mix those words up. Poisons need to be ingested or swallowed to be dangerous, while venoms need to be injected via a bite or a sting.

Some snakes can inject their toxins into their prey, which makes them venomous. However, there seem to be a couple of snake species that eat frogs and can store the toxins from the frogs in their body. This makes them poisonous if the snake’s body is eaten. Over time, many other animals will have learned that it is not safe to eat those snakes, so this trick helps keep them safe.


Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to us. You can:

* Email your question to curiouskids@theconversation.edu.au

* Tell us on Twitter by tagging @ConversationEDU with the hashtag #curiouskids, or

* Tell us on Facebook


CC BY-ND

The ConversationPlease tell us your name, age and which city you live in. You can send an audio recording of your question too, if you want. Send as many questions as you like! We won’t be able to answer every question but we will do our best.

Jamie Seymour, Associate Professor, James Cook University

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

Advertisements

A venomous paradox: how deadly are Australia’s snakes?


Ronelle Welton, University of Melbourne and Peter Hobbins, University of Sydney

Australia is renowned worldwide for our venomous and poisonous creatures, from snakes, spiders and ticks on land, to lethal jellyfish, stingrays and stonefish in our waters. Even the shy platypus can inflict excruciating pain if handled without due care.

Yet while injuries and deaths caused by venomous snakes and jellyfish are often sensationalised in the media, and feared by international visitors, a recent review found that very few “deadly” Australian animals actually cause deaths. Between 2000 and 2013, there were two fatalities per year from snake bites across Australia, while the average for bee stings was 2.2 and for jellyfish 0.25, or one death every four years. For spiders – including our notorious redbacks and Sydney funnel-webs – the average was zero.

Snakes nevertheless strike fear into many people who live in or visit Australia. When we have a higher risk of injury or death from burns, horses, bee stings, drownings and car accidents, why don’t we fear these hazards as we do the sight of a snake?

Snakes and statistics through history

James Bray, Venomous and Non-Venomous Reptiles (1897).
State Library of NSW/Peter Hobbins

When settlers arrived in Australia in the late 18th century, they believed that Australian snakes were harmless. By 1805 it was accepted that local serpents might kill humans, but they were hardly feared in the same way as the American rattlesnake or Indian cobra.

Until the 1820s, less than one human death from snake bite was recorded each year; in 1827 visiting surgeon Peter Cunningham remarked that:

…comparatively few deaths [have] taken place from this cause since the foundation of the colony.

Similar observations were made into the 1840s. What the colonists did note, however, was the significant death toll among their “exotic” imported animals, from cats and sheep to highly valuable horses and oxen.

By the 1850s, living experiments in domestic creatures – especially chickens and dogs – were standard fare for travelling antidote sellers. Given the popularity of these public snake bite demonstrations, from the 1860s, doctors and naturalists also took to experimenting with captive animals. It was during this period that official statistics on deaths began to be collated across the Australian colonies.

One sample from 1864–74, for instance, reported an average of four snake bite deaths per year across Victoria, or one death per 175,000 colonists. In contrast, during the same period one in 6,000 Indians died from snake bites each year; little wonder that around the world, Australian snakes were considered trifling.

The 1890s represented a dramatic period of divergence, though. On one hand, statistical studies in 1882–92 suggested that on average, 11 people died annually from snake bite across Australia. Similar data compiled in Victoria led physician James Barrett to declare in 1892 that snakes posed “one of the most insignificant causes of death in our midst”. On the other hand, by 1895 standardised laboratory studies, aimed especially at producing an effective antivenom, saw a global recognition that Australian snake venoms were among the most potent in the world.

In Sydney, physiologist Charles Martin claimed that Australian tiger snake venom was as powerful as that of the cobra. In 1902, his collaborator Frank Tidswell ranked local tiger snake, brown snake and death adder venoms at the top of the global toxicity table.

Over the ensuing century, this paradox has remained: why do so few Australians die from snake bites when our serpents have the world’s most potent venoms? Why aren’t they more deadly?

Deadly fear

Scientific research has delivered ever-expanding knowledge about venoms, what they do, how they work, how they affect us clinically, and their comparative “potency” based on animal studies. In response we have introduced first aid measures, guidelines, effective clinical management and treatment, which in Australia forms one of the world’s best emergency health care systems.

In contrast, countries where snakebites cause far more deaths generally face challenges in accessing affordable essential medicines, prevention and education options.

Snakes form an essential part of their ecosystems. They do not “attack” humans, mostly being shy animals, but are defensive and prefer to escape.

It would seem that venom potency is not a good measure of deadliness, and it may be a combination of our history, behaviour and belief that creates a cultural fear.

Without understating the potential danger posed by venomous snakes, what we offer instead is reassurance. As nearly two centuries of statistics and clinical experience suggest, most snake bites in Australia are survivable, if managed quickly, calmly and effectively. In fact, encounters with humans all too often prove deadly to the snakes themselves – a paradox that is within our power to change.


The authors are presenting on this topic at the upcoming Emerging Issues in Science and Society event at Deakin University’s Downtown campus on 6 July 2017. Sponsored by the Australian Academy of Science and Deakin University’s Science and Society Network.

The ConversationThe event brings together scientists with humanities and social science scholars to discuss common questions from different angles. For more information on the event and to book tickets see the event’s website.

Ronelle Welton, Scientist, University of Melbourne and Peter Hobbins, ARC DECRA Fellow, University of Sydney

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

Ants, bees and wasps: the venomous Australians with a sting in their tails


David Yeates, CSIRO

The prize for the most painful and sometimes deadly (more on that later) stings in the insect kingdom goes to … wasps, bees and ants.

There are many insects that bite, such as beetles and dragonflies, or suck your blood with long hypodermic mouthparts (mosquitoes, for instance, and sandflies). But none of these are deadly in themselves.

Mosquitoes do transmit deadly diseases, such as malaria and dengue. But it’s not the mosquito bite as such that kills; it’s the tiny parasitic microorganism that the mosquito transmits.

It’s really bees, wasps and ants – a group known as Hymenoptera – that can claim the title of deadliest insects. How did they evolve to be so painful?

How insects stings evolved

Many wasps are parasitic and developed long pointy hypodermic needles (or ovipositors) to inject their eggs into their hosts. Over evolutionary time, some of these parasitic wasps changed their lifestyle and became predatory. Some even went on to feed on pollen and nectar (bees).

A worker bee can sting a person only once.
吉輝 温/Flickr, CC BY-NC-ND

What happened to the ovipositor when wasps no longer needed to inject eggs? It became a pointy sting, a device for subduing prey with venom, as well as laying eggs.

It’s important to remember that only female wasps, bees and ants can sting; males don’t have the right apparatus.

Many of these stinging wasps, bees and ants have also become highly social insects. This means they live in large colonies such as honeybee hives, or ant nests. In these colonies, generally only a pair (a queen and a male drone, in the case of honeybees) or a few individuals reproduce.

All the rest are genetically and anatomically sterile females, and they do all the work inside and outside the hive or nest. These workers no longer need an ovipositor to lay eggs and it has become their primary weapon of choice, solely devoted to defence of the nest.

Workers use the sting to defend the wasp or bee nest, or ant colony. Queen bees lay eggs with their ovipositor and can also sting, but are usually tucked away in the nest far from harm.

Worker bees can sting humans only once – their barbed sting lodges in our skin and doesn’t retract, so the entire sting and the poison gland breaks free from the bee when it stings. The worker bee dies soon after and releases alarm pheromone, which alerts other workers that the nest is under threat.

A very good way of provoking a large number of European (or any other) wasps is to disturb their nest.
Ziva & Amir/Flickr, CC BY-NC-ND

More bees sting and release more alarm pheromones, attracting more alarmed bees … you get the picture. If you’re stung, remove the sting as soon as possible – this minimises the amount of venom injected.

A very small number of people (about one or two in every 100) can become hypersensitive after a bee sting. They become allergic to the venom, and their reaction becomes stronger when stung in future.

A highly allergic person may suffer anaphylactic shock from the sting, which can be life-threatening and requires medical treatment. A self-injecting EpiPen containing adrenalin is used to treat anaphylactic shock.

The most painful

Another common introduced stinger in Australia is the European wasp, Vespula germanica. This wasp’s sting doesn’t get stuck in our skin, so they can inflict multiple stings when annoyed or provoked. A very good way of provoking a large number of European (or any other) wasps is to disturb their nest – never do this.

A very small percentage of people can also develop an allergic reaction to European wasp stings, just like honeybee stings. In severe cases, this can cause anaphylactic shock.

Arizona entomologist Justin O. Schmidt developed the Schmidt Pain Index 30 years ago to rank the painfulness of wasp, bee and ant stings on a four-point scale.

Zero on the Schmidt pain index is the feeling of an insect that can’t sting you, such as Australia’s native stingless bees. Two is the familiar pain of a honeybee. Four is reserved for just a few heavy hitters, such as a very large spider-killing wasp, or the infamous bullet ant (Paraponera clavata) of South America.

The notorious and excruciating pain of the bullet ant lasts for 24 hours. Schmidt has been stung by more than 100 insects to create his scale, and was awarded the 2015 Ig Nobel Biology Prize for his efforts.

Some of the most common painful stingers in the Australian bush are native bulldog ants of the genus Myrmecia. These are some of the largest ants in the world and combine a painful sting with an aggressive, take-no-prisoners attitude. On top of this, many species can jump. They rate up to three on the Schmidt Pain Index.

Bulldog or jack-jumper ants have impressive long, toothed and curved jaws, but it’s the sting at the end of their abdomen that does the damage.

My most painful memory as a boy was annoying a bulldog ant nest in the Sydney bushland with a stick. Eventually a huge worker bulldog ant crawled up out of sight underneath my stick and gave me a sting on the thumb I thoroughly deserved – and will never forget.


This article is the last of our series Deadly Australia. You can see the whole series here.

The Conversation

David Yeates, Director of the Australian National Insect Collection, CSIRO

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

Deadly but cuddly? Australia’s venomous creatures don’t actually deter tourists


Bruce Prideaux, CQUniversity Australia

Part of the allure of visiting Australia is its unique animals. Cuddly koalas, inquisitive kangaroos and colourful birds are often featured in international promotions.

However, not all Australian animals are as friendly as kangaroos and koalas. Snakes, sharks, spiders, poisonous fish, marine stingers and crocodiles can cause serious injury or death.

Tourism is Australia’s largest service sector export industry, accounting for nearly 10% of total export earnings. The industry directly employs over 500,000 people.

Keeping tourists safe is important if the industry is to continue to thrive. So do Australia’s deadly animals deter visitors?

At a national level the presence of deadly animals does not appear to affect the capacity of the country to attract international tourists. After a long period of low growth, which had more to do with the high value of the Australian dollar than deadly wildlife, international arrivals are again on the rise.

Recent figures from Tourism Australia show that in the last 12 months international arrivals increased by 7% to reach 6.7 million. Spending rose by 13% to A$34.8 billion.

Keeping tourists safe

The results of just published research into swimming in the sea in Cairns give some insights into the concerns tourists have about deadly animals.

The majority of respondents were worried about dangerous marine animals, with 80% nominating crocodiles as posing the greatest danger to swimmers, closely followed by marine stingers. Concerns about sharks and stingrays were also high.

The results of the research confirmed that tourists are at least somewhat aware that they may encounter deadly animals in some areas of Australia. The vast majority of respondents (82%) reported they were aware that marine stingers might be encountered during their trip to Cairns.

However, the presence of dangerous animals did not deter people from swimming: 60% of domestic visitors and 83% of international reported going swimming. However, respondents did report taking precautions. Most (81%) chose to swim in beach enclosures and over half reported wearing a stinger-proof swimsuit while swimming.

Not all respondents particularly liked stinger-proof suits. One respondent reported that it was like wearing a full-body condom.

Apart from educating tourists about the potential to encounter deadly animals there is also a need to protect them.

In northern Queensland, as in other parts of the country, coastal communities have developed a range of strategies to protect tourists and members of the local community. Strategies generally include education, lifeguard patrols, warning signs and the installation of stinger-resistant swimming enclosures.

Measures of this nature are effective only if tourists, and locals, restrict their swimming activities to protected areas. The evidence from this research indicates that most tourists have recognised the dangers and do swim in protective enclosures.

What about the locals?

Elsewhere in Australia, the main threats are posed by sharks, crocodiles and, to a lesser extent, snakes.

In a recent article on shark attacks in Australia over the period 2002 to June 2014, Australian Geographic reported that there had been 22 fatal attacks. Almost all victims were Australian residents.

Over the same period 13 fatalities were attributed to saltwater crocodiles. Deaths from marine stingers were much lower with only four recorded fatalities

Crocodile attacks are relatively rate. However, because the coastal rivers and beaches of northern Australia that tourists find so enticing may also overlap with salt water crocodile habits, caution is required.

Protecting tourists and locals against shark and crocodile attacks is more difficult than against stingers. Once again education is a key element and based on the evidence of the low overall number of attacks each year appears to have been effective in keeping tourists, and locals, safe.

While many tourists are concerned about dangerous animals it does not deter them from visiting Australia. The message for the nation’s tourism industry is that it is important to tell tourist that there are dangerous animals and assure them that strategies have been put into place to protect them. It is also important to tell tourists that they need to adopt sensible precautions such as wearing stinger-proof swimsuits and swimming in areas that are protected.

From a destination perspective it is important to ensure that funding is sufficient to maintain protective infrastructure such as stinger nets, warning signs and consumer education programs.

It is also important to ensure that emergency services are adequately funded and that staff are trained to assist tourists who may not understand English.

This article is part of our series Deadly Australia. Stay tuned for more pieces on the topic in the coming days.

The Conversation

Bruce Prideaux, Professor of Tourism & Director, Centre for Tourism and Regional Opportunities, CQUniversity Australia

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