Factors influencing behavior and transferability of habitat models for a benthic stream fish

Abstract

The authors examined the predictive power and transferability of habitat-based models by comparing associations of tangerine darter Percina aurantiaca and stream habitat at local and regional scales in North Fork Holston River (NFHR) and Little River, VA. The models correctly predicted the presence or absence of tangerine darters in NFHR for 64 percent (local model) and 78 percent (regional model) of the sampled habitat units (i.e., pools, runs, riffles). The distribution of tangerine darters apparently was influenced more by regional variables than local variables. Data from Little River and 37 historical records from VA were used to assess transferability of models developed from NFHR data. In general, the models did not transfer well to Little River; all models predicted that either no (regional model) or few (local model) habitat units in Little River would contain tangerine darter, even though the species was observed in 83 percent of the habitat units sampled. Conversely, the regional model correctly predicted presence of tangerine darters for 95 percent of the historical records. Principal components analysis showed extensive overlap in NFHR and Little River habitat, which suggests that the two streams are ecologically similar. The suitability of Little River for tangerine darters was shown more clearly by principal components analysis than by the authors' models. Because different limiting factors may apply in different systems, the elimination of potentially important ecological variables may compromise model transferability. Ahierarchical approach to habitat modeling, with regard to variable retention, may improve transferability of habitat models

Citation

Leftwich, Kevin N.; Angermeier, Paul L.; Dolloff, C. Andrew. 1997. Factors influencing behavior and transferability of habitat models for a benthic stream fish. Transactions of theAmerican Fisheries Society. 126: 725-734.10p.