A Technique for Analysis of Utilization-Availability Data

Abstract

A statistical technique evaluating preference or avoidance of a given habitat or forage spe- cies is presented, using moose (Alces alces) distribution patterns in an area including the Little Sioux Burn of northeastern Minnesota as an example. The technique is used in conjunction with a chi-square analysis, after the chi-square has led to the rejection of the null hypothesis that a set of observations follows an expected occurrence pattern. The technique involves the use of a Bonferroni z statistic which may be used in estimating whether a specific observation occurs more or less frequently than expected. The technique provides a refinement of quantitative methods which heretofore have not been used to test a multinomial distribution applicable to the example. J. WILDL. MANAGE. 38(3):541-545 The necessity of determining preference or avoidance of a given habitat or plant species in terms of its availability has long been recognized (Glading et al. 1940, Bell- rose and Anderson 1943). A useful means of determining the statistical validity of utilization-availability data is a chi-square test of the hypothesis that animals use habi- tat or forage species in proportion to their availability to the animal, a multinomial distribution (Ostle 1963:124). A problem in using this test arises when the null hy- pothesis is rejected and a significant dif-