アカネズミの生長と発育 : I.繁殖期

概要

論文の詳細を見る
The breeding season of Apodemus speciosus was studied by the mark and release method from 1965 to 1972 at Daimonji, and by the removal method from 1965 to 1967 at Kamigamo, in Kyoto. Individuals in active reproductive states weighed more than 28-30g in males and 26g in females. The percentage of the number of sexually active individuals to adults attained two peaks for two periods from February to March and from August to October in the males, and from March to April and October in the females, respectively. It declined to 0 percent in June except 1970. Winter breeding rarely occurred. The birth season deduced from the appearance of the young was also restricted to the two periods from March to April and from September to October. This seasonal pattern of the breeding did not change appreciably through the 7 years at Daimonji and the 3 years at Kamigamo. Comparison of the breeding seasons of this species at various localities demomstrated a geographical variation that seemed to be related more intimately with temperature than with day length. Density did not affect the time of the peak of the breeding season, but seemed to affect positively the breeding period.
1974-09-30