"Male goliath birdeater 111508 002" by John/snakecollector. Licensed under CC BY 2.0, via Flickr.
The Goliath Birdeater (Theraphosa blondi) belongs to the Tarantula family and, weighing in at up to six ounces, is the most massive spider in the world. It can grow to be up to 11 inches in diameter, has a fist-sized body, and is second in leg length only to the spindly Great Huntsman. Females can live up to 20 years.
Native to the rainforests of Venezuela, northern Brazil, Guyana, French Guiana, and Suriname in northern South America, the Goliath Birdeater lives in burrows or beneath rocks or roots. It is an ambush predator, meaning that normally it lies in wait for prey to cross its path, rather than hunting food down.
It does not, as a rule, eat birds, although its name comes from an apocryphal (hard to prove or find the source of), Victorian-era story about it consuming a hummingbird. Nocturnal, this tarantula emerges from its burrow at night, often feasting upon other invertebrates, such as earthworms and beetles, and toads. It also eats small rodents, bats, snakes, and lizards, and, rarely, bird eggs or young birds. In the video below, you can watch a Goliath Birdeater capture and consume a mouse.
Covered in brown hair, the Goliath Birdeater uses two types of its hair in its defense. When the spider feels threatened, it will rub its first and second pairs of legs together to create a hissing sound that can be heard up to 15 feet away. This is called stridulation (and is the same behavior that crickets and grasshoppers use to make their chirping sounds). Additionally, the spider's abdomen is covered in barbed, urticating hairs (like the caterpillar stage of the Giant Leopard Moth) that it can fling at would-be predators. If these hairs embed in an animal's skin or eyes, they cause itching and discomfort.
Although venomous with inch-long fangs, the Goliath Birdeater's bite will not kill a person. It will, however hurt quite a bit, and has been described as somewhere between the pain of a wasp sting and hammering a nail into your hand.
Are you a budding arachnologist? Learn more about spiders from these Science Update podcasts: In Spider Web Sites, learn about a researcher looking at how spiders have established a complex social structure. Find out about engineers studying the hairs on spider legs to develop the ultimate water-repellent surface in Super Water Repellent. Hear how a tobacco-eating caterpillar creates the equivalent of smoker’s breath to scare off its spider predators in Caterpillar Halitosis. In Vegetarian Spiders, hear about a population of spiders in Mexico that subsists almost entirely on plants.
You can also check out these videos: A Wasp That Turns a Spider into the Walking Dead shows how a parasitic wasp larva turns an orb weaver spider into a slave that builds a web to host the larva’s cocoon. In Spidey Sense, Ainissa Ramirez describes the science behind spiders making webs and walking on walls, which engineers hope will lead to materials that are bulletproof and robots that can climb the side of a building.
Here are some more spider facts: Did you know that jumping spiders don't need ears to hear you? Or that tarantulas get faster the warmer the temperature? Or that the peacock spider gets its vibrant blue hue in a unique way?
Do you want to learn other #spookyscience facts in the days leading up to Halloween? Science NetLinks has some ideas that you can find here. Then check out these resources from AAAS: It's National Bat Week, so you might enjoy seeing the unique way this groove-tongued bat eats. In less cheerful news, the killer bat fungus that's been attacking East Coast bats has arrived in the West. Finally, while researchers have long thought facial expressions were universal amongst cultures, it turns out that's not actually true. You can find out more about Goose Bumps! The Science of Fear in this resource from the California Science Center.