Application of Habitat Suitability Index (HSI) models without testing in areas other than where they were generated, and claims that habitat preferences have been proven, indicate that managers and scientists believe that habitat preferences of wildlife are fixed. We tested this hypothesis by comparing habitat preferences of 2 groups of moose (Alces alces) in northeastern Alberta, Canada, to which the same habitat classes were available but differed in relative abundance. We estimated habitat availability for each of 22 radiomarked, adult female moose and divided the animals into 2 groups based on the similarity of relative habitat class abundances. We measured habitat preference for individual moose from each group during 2 seasons in each of 2 years using a simple resource selection function (RSF). We used analysis of variance (ANOVA) to compare differences between groups. Preference of several habitat classes differed between groups, indicating that habitat preferences of moose are not fixed and change as the relative abundance of available habitat changes. Managers must recognize and account for this concept in the application of habitat prescriptions or management plans.