November 21 – Eight Legs, Eight Times the Fun

Today’s factismal: There haven’t been any deaths from spider bites in Australia since 1981.

The Sydney funnel-web spider is a fearsome beast. Though it is just about two inches long, it has fangs that are longer than a snake’s and strong enough to piece a toenail! Even more fearsome is its venom; many experts count it as the most powerful spider venom in the world. Once it enters a human body, it can quickly cause paralysis and shut down the heart and other vital organs. And yet, despite the fact that this amazing arachnid lives in and around Australia’s most populous city, it hasn’t killed anyone since 1981.

Oh, sure, there have been plenty of people bitten by the critter in the past 32 years. These spiders like to wander at night (especially the males) and are very aggressive when cornered. They will frequently bite anything that they perceive as an attacker, and will do so several times, injecting a fresh dose of venom each time. So why haven’t they killed anyone? You can thank science for that.

The world's deadliest spider (My camera)

The world’s deadliest spider
(My camera)

In 1981, an anti-venom was developed that keeps the spider’s venom from killing people. The venom is made by milking live spiders (many of which are caught by volunteers {brave ones}) up to seventy times for their venom. That venom is then injected into a large animal, such as a horse; the horse then produces antibodies that attack the venom. A couple of pints of the animal’s blood is then taken and refined to make the antivenom, which is stored and given to people who were bitten.

But creating an antivenom is only half of the solution; the other half is education and prevention. If you’d like to help with that part, then why not take the House Spider Survey? The researchers are trying to learn what people think about spiders and to track common house spiders in order to help keep us safe when we encounter them. To take part, sling a web over to: https://www.societyofbiology.org/get-involved/biologyweek/house-spider-survey

November 20 – Great Bite Shark

Today’s factismal: The white tip shark may be deadlier to humans than the great white shark.

When it comes to bad press, the great white shark is king. It is featured in movies (from the classic Jaws to the classically-bad Sharknado), aquariums, and the record books (with the highest number of documented attacks on people – 272). But it turns out that the great white may just be a victim of its own publicity; the real man-killer of the seas may be the white tip shark.

Like the great white shark, the white tip shark is a ferocious predator. It likes to feast on squid, octopodes, and bony fish such as tuna (sorry, Charlie!). But, unlike the great white shark, the white tip shark doesn’t live near the shore; instead, it spends most of its time far out in the pelagic (open) ocean. And one of its favorite things to do is to follow ships, hoping for a little tasty trash of perhaps a nice, juicy sailor to fall overboard. And when it does, that’s when the white tip shark goes into a feeding frenzy so vicious that Cousteau once called them “the ocean’s most dangerous predator”.

And that habit of following ships served the shark well on July 30, 1945. That’s when the USS Indianapolis was torpedoed by a Japanese destroyer. Within 12 minutes, the ship went down and some 896 sailors went into the water. Because this was wartime, the Indianapolis had left port without enough lifeboats for everyone. As a result, most of the sailors were forced to abandon ship with no lifeboat and no life jacket; they would spend the next three days swimming for their lives – literally. And if exposure, dehydration, and exhaustion weren’t enough dangers, the sailors were soon attacked by sharks. Over the next three days, some 559 sailors would die. In this one event, the whit tip shark may have killed more people than all of the great white shark attacks put together. But because there wasn’t any firm evidence that they were responsible, the official record doesn’t give them credit for the attacks. And so, even though the white tip shark is deadlier in truth, the great white holds the official record.

But the white tip shark also has a problem: people eat a lot more of them than they do people! The long fins of the white tip shark make it especially prized for shark fin soup. As a result, it has become vulnerable over much of its range. If you’d like to help keep the white tip shark from going the way of the dodo, or just want to keep one from munching on your toes, then swim on over to the Shark Trust where you can learn all kinds of neat things about all kinds of neat sharks!
http://www.sharktrust.org/

November 18 – Dingoes Ate My Post

Today’s factismal: The dingo was introduced to Australia 4,000 years ago by Polynesian traders.

Invasive animals and plants are a problem everywhere, but they are particularly pernicious in Australia. That’s because the “island continent” has been isolated from the rest of the world for so long that most of its species lack defenses against the invaders. To make a bad situation worse, many of the invaders come from regions with more intense evolutionary competition and so have learned to do more with less; as a result, they simply out-compete the native species.

That’s why rabbits have run rampant across southern Australia and why camels clomp through the western deserts. (Amusing side note: the camels in Australia are such pure breeds that they are imported into Arabia where the camels suffer from in-breeding.) That’s why cane toads are wrecking the rain forest and why feral cats have become public health menace number one in the cities. And it is especially why dingoes have wiped out so many native species.

The dingo is a feral dog that has evolved over the 4,000 years since it was accidentally introduced to Australia by passing Polynesians. It has adapted well to Australia’s drier regions, developing fluffier ears to screen out the sand and a sandy brown coat to blend in with the background. And, over the years since it first appeared on Australia’s shores, it has adapted very well to hunting the local wildlife. Though it will attack sheep and cattle (two more introduced species that verge on being invasive), it really likes to munch on rabbits (yeah) and kangaroos (boo) making both a boon and a bane. Indeed, there are actually a few programs devoted to preserving the dingo which is in danger of being driven out of some parts of Australia.

Of course, Australia isn’t the only place with invasive species. If you’d like to find out if that new weed is an invasive or would like to report an invasive species, then head on over to My Invasive:
http://www.myinvasive.com/