2020 Volume 69 Issue 1 Pages 3-18
The demographics of the endemic subspecies of the Japanese Wood Pigeons Columba janthina nitens on Chichijima in the Ogasawara Islands was analyzed for the years 2009 to 2017 in order to evaluate the effects of feral cat control programs. After three years of full-covered cat trappings in mountainous areas, the number of pigeons dramatically increased during summer and winter and in residential and mountainous areas. Although pigeon distribution was limited within small mountainous and residential areas in 2009, by 2017 the ranges had extended by up to about 80% in the residential area and by about 60% in the mountainous area. The distributions of breeding habitats have also doubled. These demographic changes occurred coincident with the reduction of the feral cat population in the mountainous area to a minimum, and while outdoor domestic cats in the residential area was reduced. After 2014, the tendency for pigeons to increase in the mountains stopped as the feral cat population rebounded. These results show that cat controls are an effective conservation measure. In future, it is essential to develop effective methods of capture for feral cats in the mountains, and to encourage cat control programs on other islands because pigeons make move between the islands.
