The generic name 'caranguejeira' designates a myriad of species throughout Brazil (Mygalomorphae spiders, especially those from Theraphosidae and Ctenidae families). Although few kinds of these spiders have been cited during the actual research, none of them were distinguished by specific names. However, they are differentiated from each other based on their body size and color, as well as the locality they come from. The way informants recognize the local 'bird-spiders' is provided below:
"I only know one kind, the large one" (Mrs. Z., 51 years old).
"The true ones live in the dry lands" (Mr. E., 52 years old).
"Those ones from here are smaller and reddish" (Mr. E., 50 years old).
"The bird-spider is like a crab" (Mrs. P., 80 years old).
"The one from the hill [Serra da Jibóia] is very black, but the other is gray" (Mrs. N., 67 years old).
"There are large and small bird-spiders" (Mrs. S., 82 years old).
"In the caatinga [semiarid vegetation] it is large and black. The ones from here are smaller and reddish, a little dark" (Mr. E., 50 years old).
It was observed that all specimens of local bird-spiders are named under the label 'caranguejeira'. Sometimes, however, informants refer to them as 'crab' because they say these hairy spiders resemble such a crustacean due to their general morphological traits. This association is known in other parts of the country [30].
In the ethnozoological classification system of the inhabitants of Pedra Branca, bird-spiders and all other arachnids are perceived and categorized as 'insects'. This can be observed in the following testimonies:
"Insect is a dangerous object, is not it? Scorpion and spider are hazardous" (Mr. Z., 54 years old).
"Insects are those small animals: ant, beetle, spider" (Mrs. E., 84 years old).
"The spider is a bad insect" (Mr., A., 42 years old).
The inclusion of different, not systematically related animals into the ethnozoological domain 'insect' has been verified in the literature. The way human societies construct the ethnocategory 'insect' has been explained through the Entomoprojective Ambivalence Hypothesis: human beings tend to project attitudes and feelings of harmfulness, danger, irritability, repugnance, and disdain toward non-insect animals (e.g., toad, rat, scorpion, spider, lizard, snake, bat, earthworm, among others), by associating them with the culturally defined category 'insect' [31]. The idea of ambivalence comes from sociology and relates to attitudes that oscillate among diverse, and sometimes, antagonistic values. Projection results from the psychological processes by which a person attributes the reasons for his/her own conflict and/or behavior to another being. Nolan and Robbins [32] state that the organization of ethnozoological semantic domains (e.g., 'mammal', 'snake', 'bird', 'fish, 'insect', etc.) is influenced both by the emotive meaning and the culturally constructed attitudes toward these domains. Indeed, the way people perceive, identify, categorize, and classify the natural world changes the way they think, act, and feel in relation to the animals. In other words, folk taxonomies are based not only on the knowledge of biological characteristics (cognitive dimension), but also on feelings (affective dimension, here including the ideological dimension) and behaviors (ethological dimension).
Weather working on folk biological classification systems, the researcher should be aware not to consider cognitive categories as universal. Instead, they have to be 'discovered' through a proper methodological approach that reveals the conceptual paradigms [33]. For instance, in their folk entomological classification system the Kayapó Indians from the Brazilian State of Pará categorize animals with shells and no flesh as equivalent to insects [34]. The Kaxinawá Indians from Alto Juruá, Amazon forest, have the classificatory category mabu txakabu (literally, 'useless thing') to designate the different types of animals, such as snakes, centipedes, spiders, and ants. And to the seringueiros (rubber tappers), those terrestrial or flying animals that sting and have poison are classified as insects (e.g., snakes, wasps, scorpions, Ponerinae ants, and bird-spiders) [30].
Informants provided some information about where bird-spiders live and can be found, such as termite nests, tree holes, soil holes, rotten logs, litter, fence and wall base, rubbish, abandoned houses, storage rooms, rooftops, banana trees, inside bromeliads, garbage, and piles of things. Literature says that most part of their time these spiders live isolated, generally living in averted places (trees, termite nests, burrows in cliffs, and underground galleries). Big bird-spiders of the subfamily Theraphosinae inhabit under the trunks of rotten trees, near roots, in natural holes, and inside termite nests [3,9]. Avicularia spp. live on trees.
According to the interviewed people, bird-spiders are more easily seen during rainy season, especially after thunderstorms when people see them wander alongside the roads or walking on roofs:
"It likes the tiles. When it is thundering it keeps friviando [walking on roofs]" (Mrs. D., 70 years old).
"The bird-spider walks when it thunders. It appears more in the summer, in thunder times" (Mrs. P., 80 years old).
"It likes the winter better. When it rains and stops, we see them a lot" (Mr. A., 42 years old).
"When it rains it keeps walking. It goes to the asphalt, to a more open place" (Mr. E., 50 years old).
"It appears in thunder times" (Mr. J., 66 years old).
"Here in the woods it is difficult to see it, but in the caatinga we see this insect whenever there are thunderstorms" (Mrs. V., 66 years old).
Being a nocturnal arthropod, bird-spider only leaves its hideout at night or during cloudy afternoons, after summer thunderstorms when the sky is still covered with clouds, or during daytime in the inner of shadow forests [35]. It may be seen out of its burrow during daylight, although it seldom moves more than fifteen or twenty centimeters from its burrow [11]. It is interesting to notice that in Brazilian Northeastern it is said that when it is going to rain the bird-spider leaves its burrow and starts walking [36]. Maybe this behavior is influenced by the barometrical pressure that increases with the coming winter [37].
In addition, mature males usually leave their burrows to search for and breed with females. In the dryer areas of tropical habitats, rainfall and humidity are presumed to play more profound roles in bird-spiders' annual cycles, determining the season in which eggs are produced and molting occurs [5,11]. According to Schultz and Schultz [11], the presumption is that spiderlings are produced at that time of the year when food and moisture are most plentiful, probably immediately following the rainy season. That is why informants use to see vagabond spiders during wintertime.
In relation to the knowledge people have regarding bird-spider's food habits, the following testimonies were recorded:
"It feeds on beetle, centipede. What it finds it feeds on. It only eats insects" (Mr. A., 42 years old).
"It can be a cricket, a caterpillar, the same spider it takes. It is what it finds" (Mrs. P., 80 years old).
"It lives on small insects, mosquito, theses things" (T., 38 years old).
In nature, bird-spiders will eat almost anything that moves and is small enough to overpower. They have been known to eat small rodents, small lizards and snakes, small birds, insects and spiders, even other bird-spiders [11]. Because bird-spiders prey on scorpions, tarantulas, and armed spiders they must be considered as being useful to man [9]. One has already recommended that these spiders should be protected because they also feed on snakes [35].
Informants also talked about the animals that prey on mygalomorph spiders:
"The guará [raccoon] also eats it. Snake feeds on small bird-spiders" (Mr. T., 39 years old).
"It can be a snake. It is a snake" (Mrs. P., 80 years old).
"The wasp feeds on it. What does it do? It goes, digs the soil, then it returns, carries it [the spider], and puts it in the center of the hole. It is stringer than the spider" (Mr. E., 67 years old).
"Only the cavalo-do-cão [spider-hunting wasp, Pompilidae] can kill a spider. People tell that" (Mrs. V., 667 years old).
"It [the spider-hunting wasp] sits on it and kills it. It sucks the spider entirely" (Mr. A., 73 years old).
One interviewee reported that once a cat died after eating a bird-spider and then it died. That is why she buries spiders in order to prevent dogs and hens from eating them. Bird-spiders' natural enemies are storks, javalinas, skunks, coatimundis, owls, lizards, snakes, centipedes, scorpions, and spider-hunting wasps (Pompilidae). But the most impressive are huge Pepsis wasps called tarantula hawks. As Conniff [7] stresses, "The wasp's bold strategy is to slip directly under the venomous fangs and plant its stinger in the tarantula's soft tissue. The effect on the tarantula is immediate paralysis. The wasp then grads it off to burry as a macabre nursery for its offspring, laying a single glistening white egg on the victim before covering it. When the egg hatches, the wasp larva will dine on the living tarantula, avoiding the vital organs at first so that its immobilized food supply remains fresh for a month or more."
Besides tarantula hawks, small-headed flies (family Acroceridae) also parasitize these large spiders. Acrocerids lay their eggs on the spiders; when the eggs hatch, the larvae enter the body of the spider and consume internal organs [5].
Considering traditional knowledge on bird-spider's reproduction, informants said that:
"The spider makes a ball that is full of small spiders inside. I think it is the same with the bird spider" (Mrs. P., 80 years old).
"In June they are all hatching. All the insects. There is a time it has a ball of eggs. At the rainfall period. I think they are born inside the hole" (Mrs. V., 67 years old).
In fact, females spin a walnut-sized eggsac holding as many as one thousand eggs or more. They tend it carefully, airing it at the burrow's entrance and protecting it from predators [11].
During interviews, it was noticed that the most commented aspect of the interaction between bird-spiders and inhabitants of Pedra Branca is related to their dangerousness. People said that these spiders are very venomous and can cause health problems. Some of the individuals have compared the spiders' venom with that of snakes. Although they have recognized that bird-spiders can bite, they are more frightened with the hairs that cover their back and legs. According to their perception, the venom is in the hairs. Fortunately, nobody has recorded fatal episodes:
"That bites us. It has venom like the snake. If it bites, it is worse than the snake. Even dead I am afraid of that. Even the hairs, if we tread on them, they burn like a fire. We do not facilitate with these insects" (Mrs. P., 80 years old).
"The problem is not the sting, but its hairs. Its venom is in the hair" (Mrs. E., 56 years old).
"The hair broils, burns like fire. It blisters. It is like the venomous caterpillar" (Mr. A.M., 78 years old).
"I am afraid of its sting, but I am more afraid of the hair. We feel sick with fever and diarrhea. It discharges the hair. If you are going to take it, you should do it for the wind. The hair is fragile. When we touch it, it releases. It only presents hairs in its back and in the legs" (L., 28 years old).
In order to alleviate the local symptoms caused by the contact with those hairs, that is, the formation of blisters, people recommended some local healing practices, such as putting garlic, ice, some green leaf, cashew nut, and even gasoline on the affected area.
The Navaho Indians from North America say these spiders are more poisonous than the black widow, that death occurs within half an hour after being bitten unless treatment is given, or even that there is no effective treatment as there is for spider bite. A traditional medicine prescribed for bird-spider bite and scorpion sting was the gall of wolf, bear, mountain lion, bob cat, skunk, and eagle mixed with corn meal and 'peppery plant' [38].
An interesting comment was made on one aspect of the spider's behavior. According to the interviewed individuals, bird-spiders are supposed to run after someone when it gets 'angry': "It gets enraged, thus it runs after us. It is brave. It is lightness! When we tease it, it runs after us" (Mrs. L., 68 years old); "When it gets angry, it puts its legs upwards in anger. It runs after us" (Mrs. V., 67 years old). This behavior is also associated with the reproductive period, as informants said:
"When it is hatching, it gets very angry" (Mrs. E., 86 years old).
"When it is hatching, it runs after us" (A., 25 years old).
"It ran after a brother of mine. Hatching time is when it spawns and gets in a hatching mood like a hen" (Mrs. D., 70 years old).
Bücherl [9] observed that Acanthoscurria spp. are fierce spiders; they lift up their bodies in position of attack and some of them can bite with no difficult. Acanthoscurria gomesiana Mello-Leitão, 1923, when disturbed, quickly assumes a defensive attitude elevating its front legs and trying to bite [35]. Lasiodora klugi (Koch, 1850) usually lifts up in an attack pose and projects against the intruder, or then it turns its abdomen into the direction of the enemy and bombs it with a cloud of fine urticating hairs. And what concerns reproduction and hostile behavior, literature says that females can be quite aggressive while guarding their eggsacs [11]. However, they do not bite unless they are severely provoked [5].
The venominations and accidents caused by those arthropods of the Araneae order are termed araneism, which comes from the Latin word araneus, aranea = spider. Bird-spiders cause accidents with small repercussion, and there are no recordings of serious accidents between Mygalomorphae spiders and humans in Brazil [4,39]. Lucas et al. [40] recorded 91 cases of bites attributed to mygalomorph spiders at the Hospital Vital Brasil, Instituto Butantan, from 1966 to 1991. Bird-spiders' bites, however, usually just cause a low intensity and short duration pain, sometimes accompanied by a local discrete inflammation [41]. Bites of the spiders of the genus Atrax, especially A. robustus (Cambridge, 1877) from Australia, are exceptional, producing severe envenoming symptoms [40]. Data confirm that non-aggressive spiders do not harm health since "No case of accidents caused by bird-spiders in humans has been reported in Brazil as the cause of death" [9].
Spiders of the Theraphosidae family (Theraphosinae, Aviculariinae and Grammostolinae subfamilies) present an area covered with hairs that have little urticating bristles on the back of their abdomen, these hairs are visible only through the microscope. This area can contain 10,000 to 20,000 hairs per mm2 [1,3]. When it feels threatened, it rubs its hind legs against its abdomen flying these hairs away. When they hit human skin, these hairs can cause irritation and severe itching [4]. These hairs have also caused lesions on the cornea. They can also reach the high respiratory treat causing severe irritation. Symptoms however can depend on the species as well as on the sensibility of the victim [42]. It is observed local mild pain, and there is little exhuberant erythema and edema. Relief begins after 1–2 hours and no serious accidents in humans have been reported. Treatment consists only in the alleviation against pain. In those cases involving irritative or alergic phenomena, corticosteroids and antihystaminics are administered through systemic way, and corticosteroids through topical use if the lesion is local.
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