FIGURE 1. Seabird sampling effort within the Chagos Archipelago and the British Indian Ocean Territory. Boundaries of the marine protected area (a, black lines), and location within the Indian Ocean (inset). (b-g) indicates close-ups of individual atolls and islands. Black dots represent the location of individual bird count samples. Rat-infested islands are coloured in red and rat-free islands in blue. Six islands have been reported with uncertain rat status and are for representation purposes considered as rat-infested here.