Gwaii Haanas has partnered with ECCC to monitor a set of permanent plots mapping colony structure and burrow occupancy rate by excavating samples of burrows of Ancient Murrelet and Cassin’s Auklet. The data are used to determine if the breeding population areas are changing at specific key nesting colonies and if the change signifies an increasing or decreasing population trend. An estimated 1.5 million seabirds breed colonially on the 200+ islands, islets and rocks of Haida Gwaii, including globally and nationally significant proportions of 5 seabird species. A significant threat to breeding seabirds is predation by non-native mammals, notably raccoons and rats. These non-native fauna have destroyed colonies, and ANMU was designated as a species of special concern based on this threat.