EFFECTS OF SAMPLING BLOOD ON SURVIVAL OF SMALL MAMMALS

We assessed mortality due to handling and survival of small mammals th at had been anesthetized and then bled through the orbital sinus durin g a 1-year study in southeastern Arizona. Rates of return and mortalit y due to handling were not significantly different between treatment a nd control for any species. Estimates of survival based on Cormack-Jol ly-Seber capture-recapture models indicated no significant difference (P < 0.05) in survival for white-throated woodrats (Neotoma albigula) and combined species of mice in the genus Peromyscus. However, for pac ket mice (Chaetodipus) mean rates of survival were significantly lower for animals that had been bled. Removing samples of blood from wild r odents appears to have little effect on survival for most species. Low er survival in pocket mice may be due to the effects of anesthesia or the combined effects of bleeding and anesthesia on this desert-adapted animal.