The Geographical Distribution for the Place of the Occurrence of Habu Bite on the Tokunoshima Island

Abstract

A study of the geographical distribution for the place at which habu bite occurred were carried out in order to clarify the geographical features possibly relating to the occurrence of habu bite on the Tokunoshima Island. The following results were obtained; 1) The distribution for the frequency of habu bite per grid-square of 1 km2 conformed to the negative binomial distribution rather than to the poisson series, suggesting that the places at which habu bite frequently occur tend to cluster. That is, the habu bite in Tokunoshima town were found to occur frequently in the densely populated and/or well-cultivated areas. 2) The incidence rates of outdoor habu bite per unit of population differed greatly among the grid-square groups classified by cultivated land with high incidence in well cultivated groups, while the rates for indoor habu bite did not differ so widely among the groups. 3) The incidence rates of habu bite per unit of cultivated land differed widely among the grid-square groups classified by population size for both indoor and outdoor bites, being high in densely populated groups. 4) The habu-snake was frequently caught in the well-cultivated area being close to the place of residence. The fact indicated that the habitat of the habu-snake might be nearly close to the farmland. From the above, it was suggested that the occurrence of habu bite during outdoor activity might be attributed to the cultivated land habitable for habu-snake, while the place of residence in or very close to the cultivated land might be responsible for the occurrence of indoor habu bite.