石灯籠土台に営巣している Atypus karschi DOENITZ の分布型
1961 年 17 巻 2 号 p. 28-32
詳細
1961 年 17 巻 2 号 p. 28-32
This paper deals with the pattern of distribution of Atypus karschi DOENITz along the base of the dedicatory stone lantern-Ishidoro in Japanese-by the field observation.
The pattern of distribution of Atypus along the base of the dedicatory stone lantern is a Poisson pattern.
The divergence coefficient in a common year is about 0.6 on the average. In winter it is up to 1 and glides down to near 0.3 from Spring to Autumn, but it rises up above at just before 0.3, and it never shows under 0.3.
It is found that the increasing density is apt to make the random distribution draw near the uniform distribution. In May when they begin to leave the nest, they show almost like the uniform distribution and this continues till the end of September, but grown-up individual bodies show the random distribution.
The changing curve of divergence coefficient is waving curve which is compo-sed by small variance and great variance. Small variance is decided by the season, and great variance by the life history and the leaving the nest and the pattern of the larva's distribution.
