Incubation and Nest Building Behaviour of Black-Headed Gulls. I: Incubation Behaviour in the Incubation Period

摘要: I. Descriptions are given of the elements behaviour performed by Black-headed Gulls on nest during time between laying third egg and hatching first egg. 2. With three eggs in it is found that majority settling sequences complete, sitting spells relatively long, covered for almost all available time. Also most long preceded complete short incomplete sequences; lead to spells. 3. The frequency settling, proportion sequences, total amount spent sitting, used comparing different situations. It more or less than nest, abnormal shape size, fixed eggs, disturbed material, scaring stimuli near presence mate, early stage bout, produce incubation which differs from standard pattern; birds rise settle often, spend and, with exception last two cases, their sequences. On other hand times day, stages period, differences weather conditions, colour markings were not associated pattern my observations. 4. concluded relayed brood-patches particularly important determining behaviour. 5. Some problems connected use concepts "drive" "tendency" discussed. 6. Stimuli feet legs probably play a part release shifting. 7. Quivering while stimulated "novel" contact eggs.