A seasonal analysis of small mammal populations on woodlot islands

Abstract

Ten woodlot islands (surrounded by cornfields) which varied in size and isolation were sampled on a seasonal basis during 1976–1977 to study patterns of small mammal dispersal. The number of small mammal species, density of Peromyscus leucopus, and sex and age ratios of P. leucopus fluctuated on a seasonal basis. During each season island isolation was inversely related to the number of small mammal species and density of P. leucopus. Both island size and isolation were significantly related to density of P. leucopus during the fall. During the winter and spring trapping periods, all P. leucopus on the islands were males. The proportion of males on the islands during the summer and fall was positively related to island isolation. The proportion of adult P. leucopus on the islands was inversely related to isolation during each trapping season.