Seabird monitoring handbook for Britain and Ireland: a compilation of methods for survey and monitoring of breeding seabirds

The Seabird monitoring handbook aims to summarise current seabird counting and monitoring methods, 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.

It is also important to monitor other population parameters, such as adult survival rates, diet, rate of food-delivery to chicks, or growth-rates of chicks. The methods required for monitoring survival rates, in particular, are too labour-intensive for widespread use, so such data are only collected at a limited number of geographically dispersed colonies. Throughout the manual, the emphasis is on practical methods, and some methods have been omitted because (though highly accurate) they 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 detailed. For some species, several alternative methods are described, to allow for different circumstances (e.g. time available).

As well as species-specific survey methodology, the Handbook also provides general guidance on sampling and census methods, time and geographical scales for monitoring, recommended counting dates (often specific to a group of species), simple statistical methods, safety issues and basic legal advice.

Although the methods presented here deal only with assessment of population sizes, population changes, and the numbers of chicks produced by breeding pairs, such data may be combined with the results from other studies (e.g. seabird survival rates, seabird diet, predation, fish stocks) to assess why seabird numbers have changed, how might they change in future, or what factors influence breeding success