Reproduction stops during the breeding season of many rodent populations, including Peromyscus maniculatus. The proposition that water availability mediates the midseason breeding hiatus in male deer mice was evaluated in the present study. Paired testicular and epididymal weights (absolute and relative to body mass) were reduced after 10 wk of restricted water consumption. Spermatogenesis was also impaired by limited water intake. Blood plasma testosterone concentrations were reduced, but plasma luteinizing hormone (LH) titers were unaffected by water restriction. Finally, the number of offspring sired was reduced in mice with restricted access to water. Carcass water content did not significantly differ between animals with restricted (25% of ad lib.) or unrestricted access to water; however, body mass was reduced about 15% after chronic water intake restriction. Although reproductive function (i.e., reproductive organ mass, plasma testosterone titers, and sperm counts) was significantly depressed in wa...
