Burrow-nesting seabirds are island ecosystem engineers, where guano fertilizes soils and burrow-digging helps with aeration. In New Zealand, they are a cultural keystone species, where petrel chicks are harvested by Maori as a source of food and cultural cohesion. With habitat destruction and the introduction of mammalian predators, burrow-nesting seabird populations have been decimated on islands. My PhD research examined which factors facilitate or hinder the natural recovery of burrow-nesting seabird populations after predator removal – in order to prioritize sites where further population management may be required.