Laserfiche WebLink
• vegetation aistribution (m habitat affinities), then the proportion of <br />inaividuals of a species encountered in a particular vegetation type would <br />correspond to the proportion of ttie sany~ling effort dewLed to that <br />vegetation tfpe. For example if 30°s of the small mammal live traps were <br />established in upland sagebrush, then 300 of the total number of individuals <br />of all species captured over all sampling transects would 'nave been caught <br />in the upland sayebiwsh habitat if the species were distributed raru'.omly. <br />Conversely, if 90b of all Peromyscus ranicuiatus (deer mouse) captures <br />occurred in the upland sagebrush type, this would indicate a defi.-iite <br />affinity of P, maniculatus for the upland sagebrush vegetation type. <br />Tre Clu-square test (Sncdecor and Coc:u-an 1907) was used to determine <br />if the differences betl,~een the observed number of captures for a yiven <br />species in a given vegetation type and the number of captures expected on <br />the basis of a random distribution was significant. The Chi-square <br />statistic, X'-, is given by: <br />E <br />where: <br />Oi =observed number of captures (or encounters) for habitat i <br />Ei = expected number of captures in habitat i based on a random <br />distribution among habitats. <br />i••,e calculated Chi-square value was compared to aChi-square table to determine <br />if a significant difference between observed and expected number of captures <br />occurred at the 95o confidence level. If a siynificant differenre did e:<ist, <br />individual Clu-square values for individual habitats were examined to provide <br />an indication of those habitats for which a species shows an affinity or an <br />awidance. <br /> <br />-i5- <br />JUN 1 1 1980 <br />