Observations of territorial life in breeding seasen of a pair of Jungle Crow in City Tokyo (continued 3)

Abstract

Continued from the third report describing observations of family life of the Jungle CrowCorvus macrorhynchos, May 19-22, 1969 (31-34 days after hatching of chicks, 5-2 days before leaving the nest), this fourth part reports the behavior of the family from May 27 to June 13 (39-56 days after hatching, 3-20 days after flying of chicks), and this is to be continued to the detailed report of observations of June to August, already published before (Kuroda 1969).
1. On the third day, May 27, after leaving the nest, the fledglings were sitting in the nest tree above the nest to be fed by parents, but could fly about 30m to adjacent tree.
2. The female foraged wider than during chicks' nestling period and between 8.00-9.39 a.m., for example, she fed the chicks 6 times with a rhythm of feeding intervals, 25, 5, 22, 4 and 29 minutes, while the male fed only twice with an interval of 69 minutes, and in total average interval was 13.8 minutes. With this frequency a chick may have been fed 1.3 times/hour by parents.
3. The female nervonsly defended against other crows trespassing over the territory (once she flew up with half-eaten food in the throat and one feed for chicks was skipped), but the kite Milvus migrans released only a slight reaction of the female. On May 27, the female defended against 7 intruders during observation of 235 minutes and she showed apparent exhaustion in final defense.
4. On the 8th day after fledged, the chicks rested quietly during midday hours, the female's feeding intervals being as long as average 58+ minutes, and that of the male 87+ minutes; about 43.5 minutes by both parents.
5. On this day, between 13.00 and 16.00p.m. (174min.), the female foraged as far as about 400m from the nest, but the male rather stayed near the nest watching them and resting, and the defense drive against trespassing crows was low both in male and female.
6. On the 15th day after fledged, the chicks were found at a small open space with parents about 100m from the nest, where they passed some afternoon hours. The parents were more concerned with their young than the defense against other crows intruding over their tenitory. The molting of the wings and tail began in the male in advance of the female.
7. In the morning of the 16th day after fledged, the young were flying about their nest tree and followed the female who fed them rather frequently, while the male rested at high place watching his family. Thus the young were active and were fed chiefly during the morning.
8. On the 20th day after the young fledged, the family virtually broke up, since two young disappeared from the territory (after led by parents to communal roost in the previous day's evening) but a delayed young remained in the territory until 94 days after fledged (Kuroda 1969). On the above day, it was observed to peck at the food the female eating and for the first time it alighted on the ground for self-foraging, but still begged food from the female. It flew to roost with the parents in the evening, but returned to the parents' territory by itself in the next morning. acted It with the female, their movements being watched or followed by the male to join them. As already mentioned before (Kuroda 1969), this young was never rejected by parents from their territory.
9. On August 31, four days after this final young deserted the territory. The pair passed the hot midday hours in the dense foliage of the nest-tree. Now having been released from care of young, they spent a quarter of an hour sitting close by and almost four hours the female indulged in continuous solioquy utterrance of 4-6 'ka'-notes series, moving among the foliage. This strange sustained vocal behavior of the female may be a displacement activity due to a vacant mental condition resulting from the sudden life-change from a busy young-caring to a leisurely post-breeding pair-life pattern.