A 17-Year Study of the Response of Populations to Different Patterns in Antlerless Proportion of Imposed Culls: Antlerless Culling Reduces Overabundant Deer Population

SIMPLE SUMMARY: We evaluated the effectiveness of antlerless sika deer culling on sika deer population dynamics, based on the population trends in response to spatial variation of antlerless proportion in imposed culls. Deer populations tended to decrease in areas of higher antlerless culling, while they increased in areas of lower antlerless culling, suggesting that a high proportion of antlerless culling can effectively decrease the deer population. Because increasing large herbivore populations have caused environmental damage around the world, antlerless-biased culling could be a crucial measure to manage overabundant populations of herbivores. ABSTRACT: Increasing populations of large herbivores have caused environmental damage around the world, and it is necessary to improve population management strategies. Culling is a traditional management method. Antlerless deer proportions, consisting of adult female deer and fawn in Cervidae in wildlife statistics, are directly related to population increases; thus, the culling-based removal of individuals from habitats and the removal of these antlerless individuals by game hunting and nuisance control might be effective approaches for reducing population sizes. We evaluated the effectiveness of antlerless culling on 17-year density trends in the sika deer (Cervus nippon) population across an area of 1175 km(2) in Fukuoka Prefecture (Japan). In 11 out of 47 grids (area measuring 5 by 5 km), the densities of sika deer tended to decline; meanwhile, in the remaining 36 grids, the densities increased. These density trends were explained by changes in the proportion of antlerless culling, as the densities declined with increasing proportions of antlerless deer. The results affirm the theory that antlerless culling is effective in population management; it is posited that antlerless-biased culling could be a crucial measure in managing overabundant populations of herbivores, contributing to more effective conservation of forest environments.