Date of this Version
Audio censuses of Wisconsin game birds were commenced in 1948, and now include the bobwhite quail, the pheasant and the ruffed grouse, in the order in which censuses were introduced.
Briefly, audio censuses are based on the characteristic sounds given by the male of the species concerned during the breeding season. An observer strategically located at a station, or stations in the field tallies the number of individuals calling, and/or the number of calls heard during a given time period.
In Wisconsin, only the transect method is used, with the observer following a given route and making listening stops of several minutes, at approximately one mile intervals.
We here present some gleanings gathered in attempting to explore the complexities associated with audio censuses. The points raised may well result in more questions than they answer. However, we feel that it is well to at least recognize that audio censuses are not necessarily as unfettered as they might seem to be from their apparently simple structure.