Spanning 7 inches with its legs and weighing nearly a quarter-pound, this tarantula is the biggest spider in the world. It hunts big prey (but not larger than itself), including insects, lizards, and frogs. Despite its name, it rarely eats birds. During low water season, the bird-eater lives in a burrow and prowls the forest floor at night. When the rains come, it migrates into the trees. Tree trunks are highways for an assortment of animals travelling up from the water to escape the floods and back down when the waters recede. The tarantula waits in ambush and grabs the food on the move.
Local people roast and eat these spiders, which are high in protein. But they have to be careful when they handle bird-eaters, which can deliver a painful, but nonlethal, venemous bite. The tarantulas als have irritating abdominal hairs that can flick at the eyes and skin of attackers, causing humans to itch and smaller animals to have more serious reacions.

From Amazon Rising: Seasons of the River. Shedd Aquarium.