Weaver birds are small passerine birds related to the finches. These are seed-eating birds with rounded conical bills, most of which are from Sub-Saharan Africa, with fewer species in tropical Asia. Weaver birds, also known as weaver finches, get their name because of their elaborately woven nests, though some are notable for their selective parasitic nesting habits. The nests vary in size, shape, material used, and construction techniques from species to species. They live free at Prehistoric Park with nests the birds made.
We only see them once in the whole series in a scene in Saving the Sabretooth. They flew into their nests, all the while the narrator is saying, "Even for bird lover Nigel, catching the 10-foot tall Terror Bird could be a very tall order."