Design Tests for Mourning Dove Call-Count Sampling in Seven Southeastern States

Abstract

to the population of calling mourning doves (Zenaidura macroura) since 1951. Fundamental research on this technique was conducted from 1950 to 1956 as a part of the Cooperative Dove Study. Initial research on the call index was conducted by a number of workers in different parts of the United States (Foote and Peters, 1952; Wagner, 1952; McGowan, 1952, 1953; Kerley, 1952; Duvall and Robbins, 1952; Peters, 1952; Davey, 1953; and Southeastern Association of Game and Fish Commissioners, 1957). Extensive data gathered by co-operators in recent years from 600-700 routes in 44 states annually have been used for management information. Analysis of call-count data from the original management routes by life zones, biotic provinces, soils, and political boundaries has suggested some fundamental relations between populations and ecology. More conclusive evidence of these relations, however, has awaited collection of call-count population data from a statistically appropriate sampling. Although some of the original call-count routes were selected on an ecological basis, at least in the Southeast, many of the routes may have been chosen because they were known to sustain moderate to good dove populations or because they were convenient to an observer. The degree of randomness in selection and of representativeness of ar a and population of the original management routes was unknown. Data from these routes have been used chiefly to denote changes in the population of calling doves on the same routes from year to year. Attempts have been made to weight calling populations by land areas for hu ting-regulation information and for design of a nation-wide nestling-banding pr gram, using data from original management routes, because these were the best data available on dove populations. To permit area-to-area comparisons and proper weighting of call-count data from geographic areas, the population data so used either should be obtained under principles of randomization, or the sampling biases related to nonrandomness should be estimated and used as correction factors. A test o compare data resulting from random sampling with that obtained from the present system of sampling has been of high priority in the over-all dove-management program (Foote, 1953, 1957). This report summarizes results from this test.