Reasons Tarantulas Dance?
When people think about tarantulas, they hardly think about a spider doing a cute little dance. It is a common behavior that occurs after a tarantula has caught its prey and it really looks like the spider is proud of itself! The tarantula will often go high on its tiptoes and start moving in a little circle, often spinning its abdomen (which looks more like its butt) around in circles while making webs with its spinnerets.
Some believe that tarantulas might do this to help them lay down webbing so they can “listen” (through vibrations) for potential threats while they are eating (since their fangs are occupied). With their web around them, while they eat, they might be able to sense vibrations or an incoming threat (or perhaps more prey items) more easily.
Some suggest it may be more of a hygiene thing to prevent any prey guts of remnants from messing up their living area since they are very tidy creatures. Others believe they do this tarantula dance to make a sort of “feeding mat” to either save leftovers for later (I’ve seen Spidey do this before) or to help them hold prey while they digest it (since this can take a pretty long time sometimes!).
Mating of Tarantulas
For the first five to eight years of their lives, males live in a burrow, eating insects and maybe a mouse or snake. Tarantulas are wait-and-see predators; it is quite a solitary life. Then one day, they just pick up and leave in search of a willing female.
Male tarantulas are not mature until they reach age five, or eight, or ten depending on the species. Typically, in all of spider Dom, males are much smaller and do not live very long at all compared to females, which can make it to age 30. One reason for the size differential is that it takes a great deal of metabolic energy for females to produce and carry eggs, far more than it costs males to produce sperm.
. That is one reason they team up. Predators like birds or tarantula hawk wasps are likely to only grab a few meaty tarantulas as snacks, and the rest can continue their mission.
Because they spend most of their lives underground, tarantulas do not have many defenses, but they can bite or flick hair from their abdomens on to predators, causing itching and burning. When they are out in the world, it is a numbers game. The more they stick together, the more likely it is that one of the crew is going to score.
Urban sounded mind-boggled by the difficulties they face, without a map, blind, at night, for miles, and you only have a certain number of days to do this before you are going to die.
To find a female in a burrow about a foot underground, the male tries to detect vibrations. If he somehow succeeds, he will tiptoe in or knock on the web covering her burrow. His genitalia, known as pedipalps is right by his face, like two boxing gloves.
They use this glove-like apparatus to dispel sperm, and then it deflates like a balloon. After laying down a layer of sperm over the silk web, the male heads for the hills, because if he lingers, the female will usually eat him.
Different species of tarantulas have developed ways of managing the fraught moment when the male encounters the female. Some do a dance to try to hypnotize the female, so she does not strike. Others will drum their pedipalps to create a beat. Some will literally do a dance routine. Her hunger sated, the female will deposit her eggs on the sperm mat and bundle it up into a waterproof cocoon. Around three months later, she will have up to 1,000 spiderlings.
Even if the male is not gobbled up, his days are numbered. Males typically die within six months of mating. For a female, making eggs is so energy-intensive that once she makes her cocoon, she will not be able to do it again for another three years.
Tarantulas live primarily in the tropical, subtropical, and desert areas of the world, with the majority found in South America.
In the United States, tarantulas are found in southwestern states. Despite their fearsome appearance, tarantulas are not threatening to humans. Their venom is milder than a honeybee and though painful, their bites are not harmful. In fact, tarantulas have become a popular pet for arachnophiles around the world.
Female tarantulas can live up to 30 years, while males live for a much shorter time, around seven years.
Appearance and Physiology of Tarantulas
Tarantulas’ size and coloring can vary wildly depending on location and species. From front right leg to rear left leg, tarantulas range from 4.5 to 11 inches (11.4 to 28 centimeters) in length. They weigh from 1 to 3 ounces (28.3 to 85 grams) and have strong jaws and fangs. The position of the fangs is distinctive as they are parallel to each other and face downwards like a vampire. While many tarantulas are dull brown or black, some species are brilliantly colored or striped.
The most distinctive physical characteristic is that they possess very hairy legs and bodies.
Some species use these bristly hairs, called urticating’s hairs, as a defense mechanism.
If the attacker makes physical contact with the spiders, the hairs can be rubbed off on or flicked toward potential attackers. These hairs are quite irritating if they land on the eyes or mucus membranes.
Tarantulas periodically molt, shedding their exoskeletons to grow. According to the Saskatchewan Science Centre, while tarantulas are molting, they can also replace internal organs, including female genitalia or stomach lining. They can even regrow lost legs or pedipalps (short sensory appendages).
Tarantulas are by no means tiny, but if they are threatened, they will raise their front two pairs of legs in the air. This gives the impression that they are larger than they really are.
Tarantulas primarily eat insects, though some species enjoy the larger game like frogs, mice, and small lizards. Most terrestrial species of tarantulas are burrowers. Unlike many spider species, tarantulas do not use webs to catch their prey. They do, however, spin silk. If a tarantula lives in a place with dry soil, it will burrow into the ground and line the walls of the hole with silk to help keep sand and dirt out.
If a tarantula does not burrow, it might spin a burrow out of silk, or live under a log or rock. Sometimes, tarantulas spin a line of silk near the entrance to a burrow, which, reports National Geographic, acts like a tripwire, alerting the spider to prey that is nearing its home. When prey comes close, tarantulas ambush it, seize it with their legs, paralyze it with venom, and then kill it with their fangs.
They can also crush prey with their strong jaws. After the prey is dead, tarantulas inject digestive enzymes into the prey to liquefy the body and suck it up through their straw-like mouths.
Species of Tarantulas
Chilean Rose Hair (Grammostola rosea): Often called “Rosie” by arachnid-enthusiasts, these Chilean spiders are a rich brown color with pink-tinged hairs. There are, however, other color forms, they can also be gray or reddish copper. They grow to be about 5.75 inches long.
Cobalt Blue (Haplopelma lividum): Under certain lights, these Southeast Asian tarantulas are a bright, brilliant blue, otherwise they look black. They are among the most aggressive types of a tarantula, and one of the rarest.
Pink Toe (Avicularia avicularia): These smallish Caribbean tarantulas start life with pinkish bodies and dark-colored feet. As they age, they undergo a reversal in their coloration. Mature pink toes have dark-colored bodies and pinkish feet, hence their common name.
Goliath Bird-Eating (Theraphosa blondi): A real giant, this behemoth has a leg span of nearly 12 inches (30 cm). It is native to Northern areas of South America and lives in swamps. True to its name, this tarantula can eat birds, though the behavior is rare. In addition to insects, the primary prey of this species is earthworms. However, due to its size, it is capable, and it does kill and consume small vertebrates such as frogs, snakes, lizards, and even bats and rodents and occasionally young birds. But birds do not comprise their main diet.
Interestingly, tarantulas have been described as bird-eaters for centuries.
Tiger spider (Poecilotheria rajaei): This newly discovered species has a leg span of 8 inches (20 cm), and enough venom to kill mice, lizards, small birds, and snakes.