Clutch size in Kittiwakes (Rissa tridactyla) on Lundy

Kittiwake (Rissa tridactyla) numbers on Lundy have been in decline for many decades. This decline is monitored using occupied nest counts and productivity data. More recently we have begun collecting data on clutch size at one colony on Lundy. Clutch size is a direct response by a bird to prevailing conditions. Therefore, clutch size data is potentially revealing in terms of what it tells us about Kittiwake response to factors such as food availability and predation risk, in a way that occupied nest counts and productivity data is not. Calculating clutch size is not straightforward for a colonial cliff nesting bird. In this paper we present a pilot study that has calculated clutch size, and then use that data to assess differences in clutch size across the colony with reference to possible differences in predation risk as a function of colony structure. We discuss the limitations of this pilot and also key aspects of the broader ecology, which we believe should also be monitored in order to better understand the plight of this seabird