Factors affecting distribution and habitat selection of water shrews Neomys fodiens

The water shrew Neomys fodiens is one of Britain’s least known mammals and its habitat requirements are poorly understood. The purpose of this study was to determine occurrence and associated habitat preferences of water shrews, a species of conservation concern, by comparing populations in central England freshwater habitats. Bait tube surveys were undertaken at 32 freshwater sites to establish water shrew presence, half of which were found to contain water shrews. Habitat surveys were undertaken and, in addition to water shrew presence/absence data, were used to develop habitat suitability index models by means of artificial neural networks. Management intensity (occasional or frequent bankside management) was identified as the most important predictor of water shrew presence and, when combined with dissolved oxygen (0-2.99mg l-1) and water depth (