Studies of Natural Populations of White-Footed Mice: Reduction of Reproduction at Varying Densities

摘要: A population of white-footed mice ( Peromyscus leucopus noveboracensis ) on an 11-ha area was studied monthly during 1983–1989 with 600 live-traps and 254 wooden nest boxes attached to trees. I hypothesized that regulation growth would occur each year in the same at markedly different numerical levels characteristics reproductive curtailment be similar between animals populations widely densities. More than 90% known alive were captured month; <20% suckling young recorded subsequently traps. The number adults varied from 22.9/ha March 1983 0.3/ha November 1984. Significantly more adult males (56.7%) females (43.3%) study a smaller percentage reproductively mature 58 72 comparisons. yearly bimodal curve reproduction noted over 7 years significantly lower proportions condition May, June, July February–April August–October. Correlation coefficients sex April 1984 through 1989 negative for P ≤ 0.01 0.1. Yearly correlations measurements generally both sexes, but No consistent pattern change body weight nonpregnant noted. Weights testes, seminal vesicles, ovaries, uteri March, April, August, September, October. Factors producing this significant retardation density are unknown not related per se.