Sowls et al. Obtains all food at sea. Feeds on zooplankton and nekton at the surface, while hovering or briefly resting on the water. Nests in burrow or rock crevice, from which they enter and leave only at night. Returns to same site each year.
Specialized glands excrete salt through nostrils.
For nesting, prefers offshore islands without mammalian predators. Forages over open ocean. Nonbreeders remain at sea year-round. Nesting pairs enter and leave best burrow only at night. Presumably sleep in burrow or on water at sea.