INCUBATION DEVELOPMENT AND CLUTCH SIZE IN THE STARLING

Female Sturnus vulgaris had clutches of 5, 4 and 3 eggs and laid each of their eggs during the late morning hours (1 egg d -1). Females laying 5 eggs (mean laying date 130), incubated 11% of the time on the 2nd day of laying and incubation increased steadily to 80% of the time on the last day of the laying period. The daily incubation pattern of these females was very constant. During the first 2 days they only incubated during late morning. After laying the 3rd egg they incubated also in the evening and from the next morning onwards, after laying egg 4, they incubated continuously. Females laying 4 (day 139) or 3 eggs (day 150) advanced both the incubation pattern and the total time incubating per day by 1 and 2 days, respectively. -from Author