PLEA FOR STANDARD TERMINOLOGY 173 The habitat concept and a plea for standard terminology

We compared the uses and definitions of habitat-related terms in 50 articles from 1980 to 1994 to operational definitions we derived from the literature. Only 9 (18%) of the articles we reviewed defined and used habitat-related terms consistently and according to our definitions of the terms. Forty-seven articles used the term "habitat;" however, it was only defined and used consistent with our definition in 5 articles (11 %) and was confused with vegetation association or defined incompletely in 42 papers (89%). "Habitat type" was the term most commonly used incorrectly; 1 6 of 1 7 times (94%) it was used to indicate vegetation association, but habitat and vegetation association are not synonymous. Authors did not provide definitions for habitat use, selection, preference, or availability 23 of 28 times (82%). We concluded that habitat terminology was used vaguely in 82% of the articles we reviewed. This distorts our communication with scientists in other disciplines and alienates the public because we give ambiguous, indefinite, and unstandardized answers to ecological questions in public and legal situations. Scientists should define and use habitat terminology operationally, so that the concepts are measurable and accurate. We must take the challenge to standardize terminology seriously, so that we can make meaningful statements to advance science. availability, critical habitat, habitat type, operational terminology, preference, quality, selection, standardization Block and Brennan (1993) discussed the concept of habitat in the context of ornithology, stating that it could be considered one of the few unifying theories in contemporary ecology. Their opinion was based on a wide survey of papers that related the presence, abundance, distribution, and diversity of birds to aspects of their environments, and in which habitat was invoked to explain the factors and processes that contributed to the evolutionary history and fitness of animals. Other authors have likewise emphasized the importance of wildlife-habitat relationships. Specifically, "habitat use" by wildlife has been addressed by numerous researchers (Verner et al. 1986, Morrison et al. 1992, Bookhout 1994). However, we think there are several problems with current studies and discussions of habitat use that are the source of ambiguities and inaccuracies. First, although several authors have recommended that studies of wildlife-habitat relationships be placed in the proper spatial and temporal scales (Wiens 1981, Morrison et al. 1992, Block and Brennan 1993, Litvaitis et al. 1994), this has yet to happen. Researchers need to recognize that their perceptions of wildlife-habitat relationships are scale-dependent, reflecting the different scales at which different animals operate and at which they operate (Wiens 1989). Johnson (1980) and Hutto (1985), for example, proposed that animals select habitat through a hierarchical spatial scaling process, with selection occurring first at the level of the geographic range; second, at the level where animals conduct their activities (i.e., in their home ranges); third, at the level of specific sites or for specific components within their home ranges; and fourth, according to how they will procure resources Authors' address during this research: School of Renewable Natural Resources, 325 Biological Sciences East Building, University of Arizona, Tucson, AZ 85721, USA. Current address for Linnea S. Hall and Michael L. Morrison: Department of Biological Sciences, California State University, Sacramento, CA 95819, USA. Wildlife Society Bulletin 1997, 25(1):173-182 Key words