ABSTRACT
Moose, Alces alces, are the most solitary members of the deer family Cervidae, but changes occur in aggregation patterns that may affect census. Cows are more solitary than bulls, and cows with calves may be most seclusive. Aggregations tend to be largest in late fall and early winter, with bulls predominating in the largest groups. Timing of the census should coincide with the use of more open covers, when aggregations are largest and thus most likely to be seen. The probability of observing a moose increases as the size of the group in which it occurs increases. Exhaustive inspection by airplane of quadrats randomly selected but stratified according to relative moose density is commonly used. Relative density may be obtained prior to the census by preliminary aerial search or by other effort such as reconnaissance to locate tracks. Purpose of preliminary observations is to minimize variation of census results and delineate sampling units according to estimated moose density.
