DC World's Most Dangerous Animals 2of8 Tarantulas

The scary, hairy tarantula. It's prowled the earth for some 350 million years. A big spider. It's famous for its big teeth, which inject paralyzing venom into prey. They are tough predators. One species has been known to even kill birds and raid nests. Even South America's most dreaded pit viper isn't safe. But tarantulas have enemies as well. And though they will take refuge in deep burrows, they are sometimes discovered and ferreted out. Tarantulas aren't dangerous to man, but some of their relatives are. The Brazilian wandering spider bites first, asks questions later. Both pay a price for such contact. The tarantula isn't nearly as nasty, though it certainly could use a new image. Perhaps it's time to show the beauty in this beast. Maybe it's the way they creep and crawl. Or the way they take over an abandoned place, giving it a ghostly look. We have somewhere in our genes a deeply encoded fear of spiders. But unless you're a fly, there's actually very little to fear. So why not step into the spider's parlor? Their private lives are worthy of fascination, not revulsion. The way they spin silk, for example. From organs on their backsides called spinnerets, the liquid silk inside the spider's glands turns to solid thread outside the body. They all spin silk, but not all spin webs. The wandering spider doesn't like to be attached to any one place. Give this one plenty of room. It's one of only four truly dangerous spiders. This red hourglass marks another, the female black widow. She's actually quite shy and will only bite when cornered. But drop for drop, her venom is more potent than a rattlesnake's. Usually, the spider's vision is quite poor. This jumping spider is an exception. Stare at it, and all eight eyes will stare back. It uses its good eyes to hunt. Spiders belong to the arachnid family, which includes scorpions, ticks, and this non-venomous sun spider. There are some 35,000 known species of spiders, but the most impressive and largest of them are found among the tarantulas. They crawl over deserts and savannas, but prefer the hot and humid rainforests of the tropics, where they live underground and in trees. Tarantulas vary in color and size. What they all share is their hair. Lots of it. Their bodies are segmented into two parts, the abdomen in back and the cephalothorax in front. But their colors cover the rainbow. This green bottle blue has a beautiful luster. A pink starburst decorates the abdomen of the Chilean common. And the Brazilian pink has great looking legs. On average, tarantulas have about a five inch leg span. Of course, there are notably larger exceptions. No, not this one. This one, the Goliath bird eater. It's about the size of a dinner plate. Spiders like this helped fuel several legends, one being that they like to kill birds. In 1705, the German painter Maria Sabia Marion, during her voyage to Suriname, depicted a spider overpowering a hummingbird. This representation spread throughout the world and earned the tarantula the nickname the bird spider. Very few, in fact, eat birds and rarely hunt them. On occasion, though, a bird might become distracted while hatching or tending to its nest. For the most part, hummingbirds have little to fear from tarantulas. With wings that beat 80 times per second, they are extremely agile and can easily evade a stalking spider. But in the case of unguarded nests, things are different. With the parents out in search of food, the nest is left behind, unprotected. Highly specialized tree tarantulas are nimble climbers and scour for food among the trunks and foliage roofs. Nestlings, incapable of flight, run the risk of becoming the victims of many prey snatchers, including this Ecuadorian redtoe. It is more or less by accident that it will stumble on a nest during its migrations. It recognizes, through its sense of touch, that it is close to something edible. It's a cruel fate, but natural ecosystems are subject to harsh laws of survival. Other predators may likewise annihilate entire broods, losses for which the parent birds quickly compensate by laying additional clutches of eggs. Although tarantulas have been known to overpower even swift-footed animals, their vision is only mediocre. Despite their several eyes, they still have a blurred view of their surroundings, distinguishing only between light and dark. So they rely primarily on their superb sense of touch. The thick layer of body hair acts like a giant sensory organ, helping them pick up clues from the world around them. Some are furrier than others. The Honduran curly hair looks almost fresh from a blow dry. For many species in North and South America, the hairs on the abdomen provide an effective defense. Like a porcupine, the tarantula is outfitted with stinging hairs, which it won't hesitate to launch, even when only slightly irritated. The cloud can wreak havoc on any would-be attacker. The barbed hairs inflame the eyes, nose, and throat. A delicate flick from the back legs is all that's needed for the airborne assault. Of course, if the tarantula overdoes it, it eventually develops a bald spot. But it's not permanent. The hair will grow back with the next molt or shedding of its outer skin. Normally mild-mannered, tarantulas adopt a standard warning position when threatened. They rear up on their back legs and bear their fangs. As they're fairly territorial creatures, they're not afraid to show they mean business when their space is invaded, even by kin. Every tarantula is armed with two hollow fangs that act like hypodermic needles, pulling venom from nearby glands. The venom paralyzes before it kills. No human has ever been known to have died from a tarantula bite, although a lot of bad publicity over the centuries has bestowed this spider with the reputation of a killer. The early collectors in the 18th and 19th centuries mostly judged the degree of venomousness from the size of the spider's body. In fact, tarantula bites are about as painful and as dangerous to humans as a bee sting. But there was a benefit to all the misguided rumors. They induced scientists to compile more collections and to determine the variety of species. It's an ongoing process. To date, there are about 800 known species of tarantulas. But it's assumed that there are many more, mostly hidden in the seclusion of tropical rainforests, where many creatures have yet to be discovered. Time and again, we stumble across a previously unknown spider, such as this coral-colored black widow. It was discovered in Argentina in 1974. Not much is known about the effects of its venom. It's assumed, however, that its bite is life-threatening to humans. Now and then, nature's spaces open up, allowing us to get a glimpse of something completely new and odd. This arachnid was discovered in 1995. It was so strange, researchers had trouble assigning it to any group. Certain parts of the body pointed to a so-called hunting spider, but other features didn't. We are still completely in the dark about its way of life. In 1996, another species was added to South America's collection of wandering spiders. With a five-inch leg span, this new specimen is typical in size. Wandering spiders are night hunters, who prefer dark hiding places. A venomous bunch, they are also notoriously aggressive. This one's not too happy about being discovered. It's giving a clear sign to back off. The rainforests of South America provide a fountain of life for all kinds of spiders, especially tarantulas. Every year, scientists traveling to these parts document new species. No one really knows how many kinds of tarantulas there are. 800 species have been recorded, but researchers think there could be twice as many. Being shy, retiring creatures, tarantulas tend to avoid the limelight. In the rainforests, tarantulas are roughly grouped into two types, the ground dwellers and the tree climbers. The ground dwellers live quiet lives in burrows, rock crevices, and fallen logs. Once the tarantula has found a suitable home, it wallpapers it with silk. The strands don't catch prey, but rather ring like dinner bells. They pick up and amplify the sounds of footsteps of nearby insects, and the vibrations alert the spider to a potential meal. Spiders can spin different types of silk to suit their purposes. A silk with a certain kind of molecular makeup can be stronger than steel wire of the same width, or a few small biochemical changes can make the silk extremely flexible, more elastic than any synthetic material. 350 million years of earthly life have provided for virtually endless varieties. Even today, newly detected species surprise us with their unknown patterns and colors. Whatever the species, tarantulas are all fastidious groomers. Legs and feet are repeatedly combed and cleaned. It's a preventive measure against fungus and bacteria, dangerous maladies in the hot, humid rainforest. This sun tiger tarantula is a typical tree dweller. It's an expert climber. Hundreds of bristled hairs on its feet grip the bark like Velcro. The rainforest canopy at such vaulting heights is still a largely unexplored habitat. The tarantulas that live here are generally thinner, faster, and tougher skinned than the ground dwellers. With treetops towering 100 feet from the ground, just a small fraction of life here has been exposed. Only a discerning eye can distinguish between lifeless shadows and something else. This Venezuelan red stripe finds shelter inside the leaves. It's one of the smaller tarantulas. Its body is only about an inch long. Male spiders are slim, daintily built, and generally smaller than females. At the very tip of the male's two front legs are two bulbous organs with hooks attached. These organs absorb sperm, which the spider has previously deposited onto a silk web. When a male meets a female, the quarter will likely chase his potential mate feverishly in the same fashion as this Peruvian red toe. He uses his front legs to secure her fangs and keep them out of harm's way, then uses touch signals to cause the female to raise her abdomen. The male inseminates the female using its hooks. He places them in a small opening in the female's midsection and then deposits the sperm. It's a kind of indirect form of insemination. The mating process can last a few seconds or several minutes. The male must then beat a hasty retreat, lest he become her next meal. Tree-climbing tarantulas are more agile than their earthbound kin. Some are true acrobats and strong swimmers, too. But whether they live high or low, most tarantulas prefer the nightlife. It's the best time for hunting. Here in the rainforest, other creatures keep odd hours, too. Sometimes their paths cross. It's the time when giant cockroaches leave their dwellings in search of food. Or maybe it's the other way around. The tarantula is a pouncer. It captures prey by patiently lying in wait for something to crawl by. Usually, that thing is an insect. But tiny vertebrates, like this anolis lizard, must keep an eye out, too. Hungry tarantulas will pick up even the slightest vibrations of the ground. These tiny rumblings signal the arrival of a potential meal. The jaws of this Colombian lesser black penetrate like daggers, and the injected venom quickly takes effect. Tarantulas live on a liquid diet. They need to digest the food first, before they eat. Following the bite, the spider pumps enzymes into the victim, which dissolve the tissue and turn it into a kind of soup. Then the tarantula's mouth acts like a straw and slurps up the pre-digested meal. Under the cover of darkness, another dangerous hunter prowls the rainforest. This one has an attitude to match its bite. The fer-de-lance is among the most venomous snakes in South America. Like its cousin, the rattlesnake, it's deadly enough to kill humans. Almost soundlessly, it glides through the underbrush in search of prey. As it moves across the ground, the tarantula feels its vibrations. Even the dangerous fer-de-lance must continuously be on guard in nature's open spaces. Sometimes it will curl up and wait patiently for prey to wander by. But as the night wears on, this one will soon go head to head, or fang to fang, with a tarantula in a duel to the death. With the hours of the night progressing, more and more tarantulas are on the move. In the trunks and roots of the huge rainforest trees, many an eight-legged hunter lies in ambush. They are very patient. But the pit viper isn't, not on this night. Using special pits near its eyes, it's picking up the infrared signals, the body heat, of nearby animals. But this may be more than it bargained for. A life and death struggle ensues. The fer-de-lance snake is one of the deadliest in the world, but it succumbs to the tarantula's bites. It takes several minutes for the paralyzing substances to show their full impact, but the fight has already been decided. The Brazilian salmon tarantula works its jaws up and down to help break up and tenderize the meat. Then the digestive juices start to flow from the fangs. Tarantulas have incredibly slow metabolisms. This one won't have to eat again for many months. When the night fades and day breaks, the rains arrive. For a brief period, the deluge puts a damper on jungle activity. Most forest dwellers have retreated to their hideouts. The showers end as abruptly as they began, and the tarantula leaves its shelter to see what the rains have left behind. Tarantulas don't need to drink a lot, but they do need water to be able to move. Using a kind of hydraulic pressure, they push fluid into their legs to extend them. This species, the Ecuadorian blue femur, was found in 1991. Since then, it's been rarely observed, and little is known about its way of life. But like all young tarantulas, it must undergo a rite of passage called molting, and so it retreats to a protected nook. Nearly all tarantulas flip on their backs during a molt. Spiders don't have internal skeletons, so they can only grow by shedding their outer shell, or exoskeleton. Blood is continually pumped through the body cavities until the old skin starts to split. Molting can take 2 to 12 hours. It's an extremely vulnerable time for the tarantula. It can't go anywhere or defend itself until the process is complete. When they're very young, tarantulas will molt about four times a year. As they get older and bigger, they shed, on average, about once a year. Finally, all the body parts are freed, and the spider tries out its new skin. But it's in fragile shape. Even the fangs are still soft. The skin is so delicate, it can easily split, causing the spider to bleed to death. It will take several days for the outer shell to harden. Molting also provides a chance to grow back any lost limbs, like missing legs. After all these efforts, the spider is weak and dehydrated. It stopped feeding before the molt, and it will be two or more days before it can eat again. What's left behind is just a shell of its former self. Giant tropical centipedes share their territories with tarantulas. This 10-inch specimen is no exception. Despite its impressive length, it's a nimble navigator and spends most of its life patrolling the ground for food. Centipedes are among Earth's oldest terrestrial animals. These primeval creatures have existed for about 400 million years, and some can be highly venomous. Like the tarantula, this centipede is a predator. And even tarantulas aren't immune from an ambush. As quick as lightning and with all its strength, the centipede fiercely clutches the spider and drives its fangs deep inside. Just like the tarantula it's killing, the centipede has two curved, hollow fangs, which inject paralyzing venom. The centipede is a voracious eater. When it's finished, only a few spider bits and pieces will remain. Humans and tarantulas don't encounter each other very often. The one exception may be in the tropical rainforests, where large sections have been converted into plantations. Bananas, for example. Despite the invasion of their habitat, many tarantula species have adapted quite well to the changed conditions. Human presence does not appear to disturb the animals to any appreciable extent. Indeed, tarantulas are known to frequent banana collection points, most likely because the prey thereafter like to congregate here too. It may also happen from time to time that banana boxes become substitutes for burrows. And that means that sometimes the spiders hitch a ride, inadvertently, to places unknown. Even as late as the 1950s, before the advent of pesticides and chemical agents, tarantulas traveled the world. Banana cargos shipped across the oceans did not reach their destinations until after a voyage of several weeks. A large part of the tropical shipments landed in Europe. In the days when supermarkets were still a long way off, small grocers took care of the local food supply. They also handled what was then called colonial goods, which included the exotic banana. Because this much sought after produce was stored at cool temperatures, the bananas gradually ripened before they were sold. And many of the stowaways survived the odyssey as well. This unnerving sight didn't help the tarantula's reputation in those days. And its welcoming committee wasn't very welcoming. A huge monster by European standards, it was immediately disposed of. Many a newly detected species was killed that way. But preserving the specimen wasn't really a primary concern for the grocer. Serious confrontations with tarantulas are rare. Though a tarantula's bite is painful, it is never severe enough to kill a human being. But the same cannot be said about some of its bad-tempered relatives. Other spiders live among the bananas. But here, too, we must differentiate. Those building webs in the windy heights, such as this argiope, are harmless. The ones that don't build webs are the ones to watch out for. These are the wandering spiders of Central and South America. Many have a nasty disposition to go along with a nasty bite. Still, the sheer variety of species can cause confusion. It turns out this hunting spider is only a harmless double. This is the one to truly avoid. The Brazilian wandering spider, also nicknamed the banana spider, its glands are filled with a deadly neurotoxin. Those most at risk are the banana harvesters. Disregarding the small inhabitants, they cut the banana bunches from the trees by hand. Close contact with the spiders is the order of the day. And there is a great risk that the fruit bunches conceal highly venomous species. The constant vibrations drive the animal out of the bunch and ever closer to the carrier. It is only a matter of time before the easily irritable banana spider strikes with an unerring precision from a distance of almost two feet. The spider pays for the bite with its life. But after only a few minutes, the venomous effects become apparent. The venom is a neurotoxin. It strikes the peripheral nervous system, blocking the transmission of signals to the muscles. Eventually, the muscles tighten and cramp. The victim begins to sweat. His breath becomes labored. The bite wound itself becomes an area of excruciating pain, which may spread. Other symptoms can include a rapid fall in blood pressure. And in severe cases, the victim goes into shock. Before the development of an anti-venom, now widely available in South America, death from respiratory failure would occur on rare occasions. Spiders live in every nook and cranny of the planet, everywhere except Antarctica. Even in the forbidding desert, tarantulas prowl the terrain. They're just not easy to find. That's because they stay out of the sun and the heat. In the early morning, it might be possible to spot a few returning from their nightly forages. They reach their shelter as quickly as possible to escape the blazing sunlight. Sometimes they'll bivouac in a rock crevice for a time. But usually, they hide out in burrows. They'll either take over an abandoned mouse hole or dig a burrow themselves using their fangs and legs. The burrows can descend a foot or more into the ground. Despite their barren landscapes, deserts are filled with odd and extraordinary creatures. One of the most striking was discovered in 1992 in the dry territories of Central America. The Mexican flame-knee tarantula. Its bald abdomen is a clear giveaway. This one's a hair flicker. The females grow to a respectable length. Their legs may reach a span of five to six inches. Like other tarantulas, the Mexican flame-knee is territorial and sticks close to its burrow, never venturing far. The one exception is during mating season, when the males will wander for miles in search of a willing female. It's high-risk behavior. These two seem to have gotten their signals crossed. She's either misinterpreted the intentions of her gentleman caller or is simply not in a reproductive mood. Either way, he must suffer the fatal consequences for his fumbling attempts at courtship. Cannibalism is a regular part of tarantula life, one reason why these spiders live solitary lives. But tarantulas are not always their own worst enemies. There are other predators to watch out for, like the coati. This relative of the raccoon lives in South and Central America. It uses its long, flexible snout to root for grubs and other edibles. Coatis seem to have a permanently hearty appetite. They endlessly scour the ground for fruit, nuts, lizards, and bird eggs. Its sense of smell is intense, as is its hearing. Their inquiring noses can pick up the subtlest scents. Suddenly, it senses something. It's found what it's looking for. What's needed now are tactics. The scraping and scratching panics the inhabitant and drives it outside. But the veteran hunter refrains from striking it immediately. The prey is instead chased until it tires. The coati cautiously paws at the spider, hoping to avoid its painful fangs. The exhausted tarantula is finally crushed to death. For the coati, the eight-legged prey is a delicacy. Spiders are nourishing. Everything is consumed, down to the last leg. Despite the odds, the enemies, the inhospitable environment, tarantulas still manage to thrive in the desert. In 1996, a new desert species was discovered in Mexico. It looks rather inconspicuous, but that goes only for the males. The females, on the other hand, look like desert peacocks. These gender-specific colorings are actually rare among tarantulas. Like all male spiders, the main goal of this one is to lure the female from her burrow to mate. In this case, he's lucky. She seems to respond. After gingerly securing her fangs, he drums the underside of her abdomen. He then inseminates her using the hooks at the ends of his two front legs. Unfortunately, this is the end of the road for him. Even if she decides not to eat him, he has only a few months left to live anyway. Males die soon after they reach sexual maturity, after age eight or so. But the females can live 20, even 30 years. During her life, the female will mate many times to ensure many batches of eggs. Several weeks to months after mating, she begins to lay her eggs, hundreds of them. They land softly on a bed of silk that she's made. As she presses out the eggs, she also releases the male's sperm, which she had kept stored in special organs. Only now are the eggs finally fertilized. Immediately after the eggs are laid, the tarantula lines the entire nursery with protective silk. The eggs eventually disappear underneath a cocoon, a giant silk egg, which the female guards jealously. On occasion, the expectant mother will leave her burrow for a short time. But the cocoon goes with her. After about six weeks, the eggs have developed substantially. And then the spiderlings emerge. These tiny young molt at least once while still inside their silk cocoon. Their color and texture changes. Then they break out of their shell, fully developed but still small, even smaller than a housefly. Young tarantulas are left to their own devices from the first moments of their lives. Although they do stay in their mother's vicinity for a few hours, they can no longer expect her to care for them. And indeed, if they hang around too long, she'll probably eat them. Eventually, the newly spawned colony will break up, with each animal going its own way. But it's a perilous journey to adulthood. Enemies are everywhere. And many of these young spiders won't make it. Another hunter eyes the terrain, the chameleon. And of course, spiders need to watch out for their own kind. This one builds a trap door on top of its burrow. Then it lies in wait, picking up the most sensitive vibrations from above. Not every attempt is successful, but the trap door can be reset in a jiffy. And if at first you don't succeed, surprise. For those that survive, they'll take their place in the natural order, and play an important role in controlling the insect population. Meanwhile, they'll leave us alone. So why not return the favor? Why not follow the old adage? If you wish to live and thrive, let a spider run alive.