
Recommendations to cooperators 
Further study will improve the value of the survey, but 
usefulness of each count will depend upon its comparability with 
all other counts. Therefore, participants should read survey 
instructions each year and follow them as closely as possible. 
Several routes covered in 1963 were not included in the analysis 
because stops on the routes were less than 0.4 mile apart, or 
because counts were made for a period much longer than 35 
minutes. In 1963, a number of routes were covered during the 
full moon when frequency of "singing" is inconsistent. These 
counts were used in the report, since coverage in some States 
and Provinces would have been completely inadequate if they 
had not been included. Nevertheless, counts from such cover- 
ages reduced comparability of data, and cooperators should 
make every attempt to run routes under proper conditions. 
Random sampling in Michigan 
Routes used in the singing-ground survey to date have been 
established in areas where woodcock were known to be present, 
and routes have been replaced from time to time as the habitat 
changed. Since these routes are not uniformly distributed in 
all types of habitat (poor as well as good), counts from them 
are probably not representative of average population density 
in the various States and Provinces. Furthermore, these counts 
may not properly reflect changes in the relative numbers of 
birds from one year to the next. At present, we can only assume 
that drastic changes -in size of the breeding population will 
be detected. 
To clarify these important points, a study was initiated 
in 1962 to determine the feasibility of using randomly-selected 
routes to obtain representative measurements of breeding-popula- 
tion density and changes from one year to the next. With the 
assistance of personnel in the Michigan Conservation Department 
and Region 3 (Northcentral) of the Bureau, 126 routes were 
selected at random in the Lower Peninsula of Michigan. Most 
routes (75) were selected in the northern portion of the Lower 
Peninsula where satisfactory woodcock habitat is more abundant. 
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