Islands are home to nearly 20% of the world’s species, but are highly sensitive to changes, especially those involving new predators. The introduction of predatory mammals has resulted in sharp declines of island fauna, making invasive species one of the most detrimental impacts to biodiversity. The removal of invasive mammals from islands is now a primary conservation tool to protect wildlife, yet little is known of the changes that occur during recovery. What we do know is that many restored islands differ from their uninvaded counterparts, and the passive recovery of islands could be prolonged if key species fail to become established at restored sites.

As 'ecosystem engineers', seabirds are vital components of healthy island communities because their nutrient-rich guano creates and enhances habitats on land and in the surrounding inter-tidal areas. But their unique lifestyle at the interface of marine and terrestrial ecosystems exposes them to a suite of threats which has led to significant population declines. New Zealand, with the world’s richest seabird fauna, is the ideal location to study patterns in seabird movements following restoration activities. Currently, over 100 of New Zealand’s islands are in some stage of recovery, providing a series of islands in different stages of recolonisation by the world’s largest share of seabird species. This is a unique and unprecedented opportunity to understand where how competition for food and nesting space may influence community reassembly processes at restored islands.