0023-6152

AA00697606

23690

Unrefereed

0023-6152

AA00697606

A study was carried out about growth and development of Rhinolophus cornutus cornutus (short-broad wing-type bats) occupying a cave at Tono City, Iwate Prefecture in northern Japan. According to the changes in mode of life, the young period of the bats from the newborn to nearly adult size was separated into five stages, i.e., the newborn, colony-forming, flapping (and eye-open), flying and selfsupporting stages. In 1977 most of the newborn young were born between July 10 and July 12. They were left in the cave at night while the mothers go out to feed. When the infants were 7 days of age, a infant colony was formed near the entrances of the cave. Afterward the colony dissolved, and by the time the infants were 14 days of age a flapping colony was newly formed in the inner part of the cave. The bats were capable of limited flight at 22 days of age. It is likely that the bats with short-broad wings are able to fly in a short period after birth owing to their low wing loading. About 45 days after birth the mother bats vanished from the cave, and only the young left behind formed a young colony. It seems that such a mode of life in their weaning time is common to many members of the Microchiroptera. At this time, the early foraging flight of the young was observed. The mark-recapture methods were taken for assessing growth curves and their formulae of the forearm and body weight. In the first 20 days after birth, the growth rate of the forearm length was much more rapid than that of the latter half of the growth during the young period, whereas the body weight increased more rapidly in the first 10 days after birth.