COMPARISON OF TECHNIQUES UTILIZED TO DETERMINE MOOSE CALF MORTALITY IN ALASKA

Abstract

Studies to assess causes of neonatal moose (Alces alces gigas) calf mortality were conducted in two areas (Nelchina Basin and Kenai Peninsula) of Southcentral Alaska during 1977 and 1978. Equipment, techniques and costs associated with conducting the studies were compared. Calf abandonment was influenced by handling method, length of processing time and strength of cow-calf bond. Abandonment rates were lowest when only the calf was captured and no morphometric and physiologic data were obtained, and highest when both cow and calf were captured and all data were obtained.

Radio transmitters utilized in the studies doubled or tripled their pulse rates whenever they remained motionless for either four or one hour periods, indicating that a mortality had occurred. Mortality of radio-collared calves was determined by monitoring from both fixed-wing aircraft and ground stations. A total of 2,092 visual observations of radio-collared calves was made during these studies, while radio signals alone were monitored on 6,617 occasions.

A total of 104 predator killed moose calves was examined during these studies. Characteristics of calves killed by brown bears (Ursus arctos), black bears (Ursus americanus) and wolves (Canis lupus) are described. The techniques developed during these studies provided reliable data on causes of mortality which would not have been otherwise obtainable.