Frigatebird (Fregata magnificens) preening in flight. Frigatebirds are among the most agile of birds on the wing. They have the largest wingspread in proportion to their weight of any bird. Frigatebirds never alight on the ground or water; their short legs and narrow wings make it difficult for them to take off except from a height, such as the limb of a tree or a rock. Kilauea NWR, Kaua'i, Hawaii.