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<br />vegetation distribution (no habitat affinities), then the proportion of <br />individuals of a species encountered in a particular vegetation type tould <br />correspond to the proportion of the sanding effort demoted to ti~at <br />vegetation type. Por e.~~~le if 308 of the small mammal live traps were <br />established in upland sagebrush, then 308 of the total number of individuals <br />of all species captured over all sampling transects Could have been caught <br />in the upland sagebrush habitat if the species were distributed randcanly. <br />Conversely, if 908 of all Peromysc:LS~rianiculatus (Weer mouse) captures <br />occurred in the upland sagebrush type, this would indicate a definite <br />affinity of P. mani.culatus for the upland sagebrush vegetation type. <br />Tne Chi-square test (Snedecor and Coclv:an 1967) was used to determine <br />if the differences between the observed number of captures for a given <br />species in a given vegetation type and the number o£ captures expected on <br />the basis of a random distribution was significant. The Chi-square <br />statistic, X2, is given by: _ <br />(~~ Ei)2 <br />x2 <br />E <br />where: <br />Oi =observed number of captures (or encrounters) for habitat i <br />Ei =expected number of captures in habitat i basa3 on a randcan <br />distribution a:mng habitats. <br />ire calculated Chi-square value-was compared to a Chi-sgLiare table to determine <br />if a siy-niiicant differt~~ce between observed and exixxcted number of captures <br />occurred at the 958 confidence level. I£ a significant difference did exist, <br />individual Chi-square values for individualhabitats were ew3mined to provide <br />an indication of those habitats for which a species shows an affinity or an <br />avoidance. <br />-15- <br />L <br />lux i t (9ao <br /> <br />(Revised July 2006) Attachment 2.04.11-1-22 <br />