BREEDING PERFORMANCE OF PUFFINS FRATERCULA ARCTICA IN RELATION TO NEST DENSITY, LAYING DATE AND YEAR

Summary The paper presents data on the breeding and predation of Puffins in two areas of different nest density within a single colony on Dun, St Kilda group, Outer Hebrides in 1973‐78. Within a season birds laying early had a slightly higher nesting success than birds laying late, but laying date had little influence on the peak and fledging weights of young. The main disadvantage in late laying was a reduced chance of relaying if the first egg...