TWENTY-PLUS YEARS OF AERIAL MOOSE CENSUS IN MINNESOTA

Aerial moose censuses have been conducted on two major areas in Minnesota using plot samples from 1959 to 1981. Stratification and optimal allocation of plots has increased the census precision. Accuracy was improved in the northeast by using a crew of four in the aircraft and conducting the census in early December through January with a ground cover of 20-80 cm of uncrusted snow. Moose populations in northwestern Minnesota increased at the rate of 4% per annum from 1960 through 1972, and at 1% from 1973 through 1981. The true population changes in this area may have been masked by the addition of an adjacent, but ecologically dissimilar, unit to this census area in 1972. From 1977 to 1981 this population has increased at the rate of 8% per year. In northeastern Minnesota the moose population increased from 1959 through 1966, decreased from 1966 through 1974, and increased from 1974 to 1981 at the rates of +3, -5 and +12% per annum, respectively. The data obtained from the census has played an important role in the management of Minnesota’s moose populations