Pregnancy in cactus mice: effects of prolonged copulation

Science  14 Feb 1975:
Vol. 187, Issue 4176, pp. 552-553
DOI: 10.1126/science.1167700


The postejaculatory copulations of cactus mice are demonstrated to function in facilitating neuroendocrine responses necessary for pregnancy. Whereas estrous cycles were altered after just 10 percent of the tests terminated after one ejaculatory series, females became either pregnant or pseudopregnant after 80 percent of tests continued at least to sexual satiety (30 minutes with no copulations).