SIZE CLINES IN THE BAT PIPISTRELLUS PIPISTRELLUS RELATED TO CLIMATIC FACTORS

(Uploaded by Plazi for the Bat Literature Project) Adult female P. pioistrettus from colonies have been caught and measured in various parts of Britain. Sample sizes averaged 91 bats for 21 sites. Forearm means ranged lrom 31.00-32.88 mm and many were significantly different. Clines of increasing bat size radiated from west central England indicating the existence of discreet breeding populations. Significant correlations were obtained between increasing bat size with decreasing )emperatures and saturation deficit, and with increasing relative humidity Thus P. oipistrettus seemed to conform to Bergmann's rule for a homeotherm.