Showing papers in "Virginia journal of science in 2018"
TL;DR: In this article, changes in the composition of two small mammal communities were studied during 8 and 9 years of ecological succession in southern Chesapeake. Virginia, using monthly live-trapping on grids of similar size and history since their abandonment as agricultural fields.
Abstract: Changes in the composition of two small mammal communities were studied during 8 and 9 years of ecological succession in southern Chesapeake. Virginia. Using monthly live-trapping on grids of similar size and history since their abandonment as agricultural fields, we learned that house mice were early colonists on one grid but not the other. Two species of herbivorous rodent and the granivorous eastern harvest mouse were numerically dominant on both grids across the study. Some species disappeared early on one grid but persisted to the end at the other. The two arboreal small mammals, golden and white-footed mice, were most predictable between sites, showing up at year 8, after significant woody elements were present on the grids. The greatest abundances of small mammals (and probably greatest total biomass too) were seen between years 4 and 6 of ecological succession.
3 citations
TL;DR: During studies of the annual cycle of reproduction in the hispid cotton rat (Sigmodon hispidus) in southeastern Virginia, an anal (more specifically, perineal) gland is discovered that is present only in males during the breeding season.
Abstract: During studies of the annual cycle of reproduction in the hispid cotton rat (Sigmodon hispidus) in southeastern Virginia, we discovered an anal (more specifically, perineal) gland that is present only in males during the breeding season. The perineal gland encircles the lower end of the rectum and has ductal connections to the urethra, through which its secretions probably are delivered. This fatty gland is highly developed in breeding males but, like the testes and seminal vesicles, regresses during the winter non-breeding season. The prominence and cyclicity of the perineal gland suggests that it somehow facilitates normal reproduction. The combined mass of testes, seminal vesicles, and perineal gland constitutes only about 0.01 percent of the body mass of large males during the non-breeding season, but as much as 4.8 percent of body mass during the breeding season. Thus, males devote a large amount of energy to growing and maintaining these glands in anticipation of and during the breeding season. Despite two field trials, the function of the perineal gland and the nature of its secretion are unknown.
1 citations