Bird-spiders belong to the Mygalomorphae suborder, Orthognatha group. Differently from the spiders of the Araneomorphae suborder, in this group of spiders the chelicerae move in parallel with the longitudinal axis of the body, there are two pairs of lungs, and their venom glands are situated entirely inside the basal segment of the chelicerae [1]. There are nearly 2.547 known species and they are found in all continents, except Antarctica (Paulo César Motta, personal communication, 2006). Considering the family Theraphosidae, a total of 897 and 170 species have already been described in the world and in Brazil, respectively [2]. They grow up through skin changes, and females still go through these changes even after they are adults [3]. Theraphosa blondi (Latreille, 1804), which lives in the Amazon forest, is up to 26 cm long [4].
These spiders usually dig burrows when they are spiderlings and live in them for many years, enlarging them as necessary. Once established at a site, an individual tarantula usually spends its life there, hunting in an area only a few meters adjacent to its burrow [5]. According to Smith [5], courtship involves cautious approach by the male, who touches the female with his front legs, then moves in a way that identifies both his gender and species. If the female is receptive to his tentative advances, she abandons her burrow and ultimately postures with her cephalothorax raised. She remains inactive while the male approaches her from the front. He uses special hooks on the first pair of his walking legs to hold the female's fang-bearing chelicerae during insemination. After the sperm have been deposited in the female's abdominal genital opening, the male disengages his hooks and departs briskly.
Erroneously, mygalomorphs are referred to as tarantulas by many people, but the true tarantulas are araneomorph spiders of the widespread genus Lycosa [6]. The name 'tarantula' comes from a cult in Taranto, Southern Italy where the bite of a spider (Lycosa and Latrodectus) served as a pretext for dionisiac reunions of a frenetic dance [7]. The symptoms of the affliction may include dizziness, weakness, feelings of anguish, psychomotor agitations, stomach and muscular pains, nausea and increased erotic appetite in its acute phase [8]. This author states that tarantism is related to Saint Paul's legend of the eradication of venomous creatures from Malta. In common sense, however, the term tarantula means almost all big and hairy spiders.
On the other hand, the name 'bird-spider' comes from the fact that some mygalomorphs feed onsmall birds. The first European explorers in South America named the spider after seeing a specimen (Avicularia avicularia Linnaeus, 1758) eatinga small bird. Another reason touse this name could be that some tree spiders drop to the ground when there is danger, spreading their legs that are covered with hair, and gliding like a little bird from branch to branch. In Central America they are called gorse-spiders because of the mistaken idea that their bite can cause a horse's hoof to fall off [7]. In Colombia giant bird-spiders of the genus Theraphosa are named rebienta-caballo or mata-caballo (killer horse) [9].
These 'big spiders' are culturally significant for different human societies throughout the world [10]. They can be found in myths and legends, and usually play important roles in daily life of many cultures [11]. In Cameroon, for example, traditional seers use them to foretell the future: the seer sets a container over the spider's burrow, and places an assortment of elaborately patterned leaf cards with advices around the entrance. The spider has to rearrange the cards to yield such advices [12]. In Laos people are used to eating bird-spiders. They take their fangs off, then they roast them in broaches, and after that they eat them with salt or in pepper sauce. Sometimes, however, parts of these spiders, usually abdominal contents or the eggs of the big females, are eaten raw [13]. The Khmer of Cambodia are reported to eat large theraphosids deep-fried in oil and served on skewers [14]. The Piaroa and the Yanomamo Indians of the Amazon Basin eat roasted Theraphosa blondi and other large species, which they extract from their burrows [14,15]. Paoletti and Dufour [16] have summarized all available data for Amazon.
The medicinal use of bird-spiders has also been recorded. Among the Tzeltal from Chiapas, Mexico these arthropods are used for treating tumors. They are induced to sting the affected area [17]. In Brazil the 'tooth' of a bird-spider is attached around the neck in order to treat erysipelas [18], while its fangs are recommended against toothache in the state of Alagoas [19]. These 'teeth' are also used as an amulet that is attached on a child's neck to rid it of evil eyes [20]. Cascudo [21] recorded the usual belief that a child who wears such amulets will have a white, strong, resistant denture. In the city of Feira de Santana, Bahia State, the powder of a toasted bird-spider is turned into a tea and offered for whom suffer from asthma [22].
Although many people consider bird-eater spiders as repulsive and dangerous creatures (helped by horror movies such as Tarantula), there is an increasing proportion of the world's population that actually enjoys the company of these arachnids, since a number of them are now popular as household pets. Unfortunately a great amount of specimens comes from dealers who travel to tropical countries searching for these large spiders [23]. This has endangered a few species, such as the Mexican red-kneed Brachypelma smithi (Cambridge, 1897) which has been over-collected and is now cited in the CITES Appendix II [6].
Despite the close association between spiders and human communities, few ethnobiologists and anthropologists have paid little attention to knowledge and use of them [24]. Considering that ethnozoological studies on bird-spiders are rare in Brazil [25,26], this paper deals with the perception, knowledge and behavior of these spiders in a small community from Bahia State, Northeastern Brazil. It is a brief contribution towards a new branch of research, ethnoarachnology.
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