Built for eating and loving, but not fighting; the giant toucan bill is used in mating ritual “fruit tosses,” though both sexes posses the over-sized beaks.
As a weapon, the bill is a bit more show than substance. It is a honeycomb of bone that actually contains a lot of air. While its size may deter predators, it is of little use in combating them.
But the toucan’s bill is useful as a feeding tool. The birds use them to reach fruit on branches that are too small to support their weight, and also to skin their pickings. In addition to fruit, Toco toucans eat insects and, sometimes, young birds, eggs, or lizards. (NatGeo)