Body Size and Population Density of Bufo japonicus formosus from Nobeyama Highland, Nagano

Abstract

A population of the toad, Bufo japonicus formosus, was studied in Nobeyama Highland (altitude 1350m), Nagano in 1994 and 1995. Breeding activity of the toad occurred from late April through early May, and their summer activity was observed from late May through late September. The mean snout-vent length (SVL) was 94.2mm (N = 77, SD = 8.2) in males and 95.5mm (N=69, SD = 8.0) in females. The SVLs were smaller than those from lowlands. The mean body mass was 103g (N=76, SD = 25.9) in males and 104g (N=57, SD = 29.1) in females. The rate of recapture within a year was 0.333 in males and 0.320 in females, and there was no significant difference between the sexes. Population density estimated by Petersen's method was 5.9/ha, and the confidence interval (95%) was 3.9-8.0/ha.