All-day observations at a robin's nest

TitleAll-day observations at a robin's nest
Publication TypeJournal Article
Year of Publication1963
AuthorsJr. OSewall Pet
JournalLiving Bird

Three all-day records of activities were made at a Robin's nest in Michigan, two during incubation and one during the dependency of the young. Incubation was performed by the female, except for one two-minute attempt by the male. Time spent by the female at the nest during incubation was nearly the same on both days, being about 80 and 77 per cent of the time (27 and 23 attentive periods) between her departure from the nest in the morning and her final return in the evening. Her shorter periods of attentiveness were more numerous in mid-morning and mid-afternoon. While on the nest she was rarely still for more than a few minutes. Her movements were usually associated with four different actions: standing, turning the body, preening, and turning the eggs. On the two days a total of 143 and 118 actions was recorded. There was no correlation of actions with time of day and there was no evident sequence of actions. The female was not observed to sleep during the day. On each of the days the male appeared at the nest, or in the vicinity, 11 and 3 times for short periods. In four of these instances he fed the female, and the female, in one of the instances, pushed the food received at one of the eggs. The female spent 52.4 per cent of the time (63 periods) brooding the young during the day. The brooding periods averaged shorter between mid-morning and mid-afternoon and were more widely spaced in the early afternoon. The male did not brood the young. The female and male fed the young 5 times per hour (the female 2.7 and the male 2.3 times). The length of intervals between feeding visits averaged 11.6 minutes (by the female 20.5 and the male 21 minutes). The young were fed more often after 1:00 PM than before, and the least often before 7:00 AM, around noon, and in the evening after 7:00. While incubating, the female ignored the close approach of an Ovenbird and Red-eyed Vireo, but later, while caring for young, drove away a Black-and-white Warbler and a Baltimore Oriole which came near the nest. During the period of incubation the female and, on another occasion, the male pursued another Robin which appeared in the vicinity of the nest.