This handbook attempts to summarise current seabird counting and monitoring techniques, relevant to British and Irish colonies. It presents step-by-step procedures for each species for censusing/monitoring populations and for assessing productivity (chicks fledged per breeding pair), and is designed to be of use to reserve wardens, volunteer fieldworkers and others wishing to collect basic information on breeding numbers, population changes, and breeding success. The information obtainable using the methods described is intended to be appropriate and sufficiently accurate for general conservation monitoring purposes.

Throughout the manual, the emphasis is on practical methods, and we have omitted some methods which (though highly accurate) are too labour-intensive or time-consuming for general monitoring use. For some 'difficult' species or colony-types (e.g. burrow-nesting puffins), the methods described are necessarily rather detailed. For some species, several alternative methods are described, to allow for different circumstances (e.g. time available).