Predicted areas of increase in seabird abundance under a scenario of rat-eradication. Rat-free distribution predicted from BRT model using a rat-free scenario (a-c), and a rat-invaded scenario (d-f), where each island is set as either ‘rat-free’ or ‘rat-invated’ respectively. These models represent the distribution predictions under complete eradications of rats and a full invasion of rats respectively. Hence, an approach to understand the variations of distribution is calculated by subtracting the rat-invaded minus the rat-free models. This yielded to the net gain in bird abundance under a scenario of rat eradication (g-i). The upper 95% quantile increase of the net gain is also showed (j-l). White shaded areas indicate areas nearby currently rat-free islands in which a rat eradication programme would not have any effect since they are already at the theorised maximum abundance.