'Akiapōlā'au get the most buzz about their beak, which is uniquely adapted to their insectivore diet.
First, they use their strong lower bill to peck holes in tree branches. Then, they use their decurved upper bill to forage for insects and larvae within the branch. If you happen upon this "Hawaiian woodpecker" at lunchtime, you might hear the tap-tap-tap sound of their beaks pecking at the trees as they hunt for food.