DISPERSION AND HABITAT PREFERENCE OF THE WATER VOLE (ARVICOLA-TERRESTRIS) ON THE RIVER THAMES

Investigated the dispersion of water voles (Arvicola terrestris) over a two year period on a 1.6 km stretch of the River Thames near Oxford, England. Dispersion was significantly clumped, most pronounced for ad ult females, followed by juveniles and feast for adult males. The rive r bank was divided in 32 50-metre sections and data on the vegetation and physical features of each section were analysed with the frequency of water vole catches in each section to determine habitat preference s. Water vole catches were positively correlated with water depth, Urt ica, Phragmites, and short unidentified grasses and negatively correla ted with bank height, bank depth, Polygonum, Phalaris, Sparganium, Jun cus. The favoured plants all provided food and also cover in the case of Phragmites and Urtica. Shallow water was avoided even though its as sociated emergent macrophytes provided cover. Deep water may allow the water voles to escape predation by diving and swimming away.