EFFECT OF USING THE DOUBLY LABELED WATER TECHNIQUE ON LONG-TERM RECAPTURE IN THE BROWN LONG-EARED BAT (PLECOTUS-AURITUS)

A banding study of Plecotus auritus was carried out in northeast Scotl and between 1978 and 1991. A total of 526 bats were caught, and of the se 211 had the procedures involved in the doubly labelled water techni que performed on them (injection with isotopes, and in most cases remo val of a small blood sample from the interfemoral vein). Recaptures of these bats in subsequent years allowed a direct comparison to be made between the proportions of recaptured bats which had been injected, t hose which had been both injected and bled, and those which had had ne ither procedure performed on them. The proportion of bats recaptured d id not differ between the test and control groups, which suggests that these procedures had little or no effect on the long-term survival of this species, over and above any effect of the initial capture and ha ndling.