Characteristics of Female Reproductive Success in a High-Density Population of the Japanese Serow, Capricornis crispus, in Akita, Northern Honshu, Japan

Abstract

There have been few field studies to date on female reproductive success in the Japanese serow, Capricornis crispus. Data were collected on female reproduction and kid mortality in a highdensity population in Akita City, Japan, for seven years from 1979 to 1985. The parturition rate from 1979 to 1984 was at least 81.1%, and the annual variation (73.3-85.7%) was not significant. Each adult female usually gave birth to a single kid in successive years and may have intermittently had 1-or 2-year interruptions of parturition. In the seven females observed from zero or one year of age, four (57.1%) and three females (42.9%) first gave birth at three and four years of age, respectively. The kid mortality rate from 1979 to 1984 was 54.7%, and the annual variation (27.3-88.9%) was significant. Compared with the pregnancy rates of culled serows in low-density local populations, parturition rates were remarkably high in the study area, perhaps because of good nutritional conditions. In low-density populations such as red-listed areas, it is necessary to monitor fertility rates as well as population densities to avoid local extinction.