Daubenton's bat distribution along rivers - developing and testing a predictive model

1. This study aimed to develop and test a predictive model of Daubenton's bat Myotis daubentonii distribution and abundance at waterway sites in England and Wales. 2. A preliminary 'core' model to predict Daubenton's bat distribution, developed in 2003 and containing terms relating to biological water quality, waterway width, mean annual discharge and the presence of trees, was re-fitted to more comprehensive datasets. A 'data mining' exercise was conducted after testing the core model, in order to investigate other important variables and to suggest alternative models, with the overall aim of improving the confidence and utility of the results. 3. On average, Daubenton's bat activity was higher on larger waterways with abundant woodland nearby. There was, however, considerable variation in the levels of activity predicted by the models, possibly due to site-specific factors. 4. Daubenton's bat activity was significantly related to aquatic macroinvertebrate diversity, demonstrating the potential relevance of this species as an indicator of a pollution-sensitive biodiversity group. High aquatic macroinvertebrate diversity was associated with good chemical water quality. 5. The analysis demonstrates that Daubenton's bat activity on rivers can be predicted from habitat and water quality data, although the precision of these predictions is low. Where practical, field surveys yield better information. Copyright (C) 2009 John Wiley & Sons, Ltd.