Abstract
ThQ Stephens' kangaroo rat {Dipodomys stephensi. Family Hetero- <br /><br />myidae) is an endangered desert rodent of southern California. The historic range <br /><br />of Z). stephensi has been severely reduced by urban and agricultural development, <br /><br />and remaining habitat is considerably fragmented. We estimated the minimum <br /><br />viable population size ofD. stephensi from a demographic model that incorporated <br /><br />information about survivorship and fecundity in relation to stochastic variation <br /><br />in rainfall. According to the model, a population of 13,210 individuals has a 95% <br /><br />probability of persisting for 100 years. At a density of 10 individuals/ha, this <br /><br />value corresponds to a reserve size of 1321 ha. Based on this estimate and maps <br /><br />of current distribution, land use, and soil type, we suggested nine potential reserve <br /><br />sites and recommended that at least three reserves be estabhshed to secure per- <br /><br />sistence.
