Seabirds are usually the first animals to colonise an island formed by an oceanic volcano. Young seabirds usually return to breed in the place they were raised, so new breeding colonies grow slowly at the beginning.

The size of seabird populations often depends on whether food is within easy foraging distance of their breeding site. Pulu Keeling National Park (North Keeling Island) is the only seabird breeding area within a radius of 900 km - so it is of major importance to the ocean's seabirds.