9225081 Gavin We propose to examine the relationships among population size, population structure, and dispersal in determining the viability of a mammal, by focusing on demographic and genetic characteristics. The northern Idaho ground squirrel ( Spermophilus brunneus brunneus ) will be studied. This species is found in only 21 populations ( 18 extant and 3 that have gone extinct since 1983 ), which contain in aggregate total no more than 1,000 individuals. The range of population sizes and degree of isolation of populations of this species make it a model organism for studies of population viability. Moreover, this small mammal is tractable to work with: it can be trapped, marked, and observed with relative ease. %%% Our objectives are to determine 1) the role that immigration plays in maintaining population size and genetic variation 2) if birth, death, and dispersal, rates in small, isolated populations are different than this of larger, less isolated populations, and 3) if the level of genetic variation has been maintained equally in several isolated populations, when all 3 situations contain approximately the same number of individuals. We propose to use VORTEX, the most widely used simulation model for Population Viability Analysis, to evaluate the effects of dispersal and population structure on the viability of this rare rodent. 24+ a4. Fa 2 ` F 7 6 & F 7) 6 * F 79 6 & ` P `)W `55 Section Layout &Line Numbers... Apply to Section: &Section Start: Vertical Alignment &Top &Center &Justified Suppress &Footnotes Add L&ine Numbering E very New &Page Eve z b ! ! ! F ( Times New Roman Symbol & Arial " h e e # W - Gayle Edmonds Gayle Edmonds
