Monitoring the Atlantic Puffin Fratercula arctica, Common Guillemot Uria aalge and Black-legged Kittiwake Rissa tridactyla breeding populations on Hornøya, northeast Norway, 1980-2000

The breeding populations of Atlantic Puffins Fratercula arctica, Common Guillemots Uria aalge and Black-legged Kittiwakes Rissa tridactyla have been monitored on Hornøya, East Finnmark since 1980 as part of the Norwegian seabird monitoring programme. Whereas numbers of Puffin burrows in plots monitored in 1981 - 1993 increased at a rate of 2.6% per year, there was no subsequent trend in counts made in a new scheme of circular plots started in 1990. Numbers of Common Guillemots collapsed between 1985 - 1987 but have since increased in all plots at a rate of 11.6% per year. Kittiwake numbers dropped significantly (1.5% per year) between 1980 - 1994, but stabilised between 1994 - 2000. Suggestions are made for improvements to the monitoring scheme to overcome inconsistencies in changes in numbers between plots (e.g. of Kittiwakes), to increase the sensitivity of the counts and for additions to help explain why any changes in the populations occur.