Selective Correlation of Egg Size with Chick Mortality in the Black-Headed Gull (Larus ridibundus)

Publisher Website
Google Scholar
Abstract
The correlation between dimensions of 450 eggs and chick mortality in the black-headed gull was studied in 1974 and 1975 in a colony in Finland. Egg dimensions were measured and the date of laying, hatching sequence of eggs, hatching weight of the chicks, and survival of 350 chicks during the 1st wk of life were determined. Selection pressures, which prevent continuous increase of egg size in larids, are discussed. A mechanism based on egg size for regulation of production of young is presented, as opposed to a mechanism based on clutch size. The former can be found in larids, and is related to K-selection. The latter can be found in many passerines, e.g., the great tit, and is related to r-selection.