Why are Tarantulas Sometimes Called Bird-Eating or Baboon Spiders?
It 's an age old question and I'm sure you'd like an answer, well here goes:
However, Tarantulas are opportunistic predators and a passing bird or chick will be just as welcome as any other prey. They normally eat mostly invertebrates and small mammals, also small lizards, frogs, snakes, etc. are eaten by some species. Arboreal species, such as any of the many members of Avicularia are most likely to use birds and hatchlings as part of their diet as they live almost entirely in the trees and other high places that birds tend to nest and roost.
Why are they known as Baboon Spiders? Well, one suggestion is that Baboons consider these large spiders to be a tasty treat and eat them eagerly (as both these spiders and Baboons are found in the same regions of Africa), others suggest that its the colouring (similar to a Baboon).
These spiders are part of the Theraphosidae family and are therefore commonly grouped under the common name of Tarantula.