Masked boobies form colonies in the open, generally on offshore islands. Both males and females possess black-masked white faces and black tails, but males differ in that they have black feathers on their body and wings. The males gather on open limbs where they wait to display to the females that fly by. Each male establishes a territory to which he repeatedly flies back to and attempts to attract a mate. In order to attract a mate the male performs many types of displays, including "sky-pointing" (stretching the head upward and pointing the bill directly at the sky) and "branch-shaking" (vigorously shaking a tree limb). In addition, the male will vocalize a cooing sound while performing those two actions. The female flies low over the displaying males and selects a mate based on the vigor and quality of the displays. Once the female has selected a male, the two birds come together and touch bills or caress their bills on each other's body before mating.