, The purpose of the type of count described above is to obtain an 
index of population abundance in the region sampled, not to determine 
the total population in any area. The principle involved is to make 
the observations as standardized as possible both as to time and space, 
so that they will be comparable with the results obtained in different 
regions and in different years. By and large the cooperators took to 
this new method very well and secured a good volume of data on the 
basis suggested. The chief objection was to the suggestion that the 
records be confined to ground calls or "peents." Summing up the ob- 
jections to this in the northeast, Mendall, in his report, points out 
that physical conditions sometimes make it impossible to use only ground 
calls and that this year's census takers indicated that on 59 percent of 
their routes all data consisted of ground calls only. 
‘Evidently some of the cooperators th ught that the stops had to be 
O.l| miles--no more, no less--and felt that in a region of scattered 
woodcock habitat there would be too many blanks in the observations. 
Actually, it will be noted, the instructions said "no less than Ol; 
miles apart," which gives the observer plenty of latitude in spacing 
his stops as.widely as necessary to miss unproductive habitat. 
Another frequently expressed objection was that the stops 0.l 
miles apart were too widely spaced to hear all the birds that were 
calling along the route. - It should be emphasized that there is no 
intent to hear all the woodcock with singing grounds along the route, 
but to obtain an index of abundance based on those singing at definite 
points along the route. The O.-mile minimum interval was selected . 
to allow a margin of safety against recording the same singing bird 
twice. The principle of the new method is to obtain an index of 
abundance in terms of average number of birds recorded per stop. It 
is presumed to have the advantage of sampling a larger section of . 
country than was possible by the old continuous-count method, thus 
giving a truer index of the over-all woodcock population. 
There were other observations this year which had bearing on 
various phases of the breeding-ground-count procedure. Blankenship, 
in his report, says that the full moon did not seem to have any effect 
on the number of birds active or on the length of the first period of 
evening activity, and that the distance that birds could be heard call- 
ing was such that the distance between stops might be reduced to 0.3 
miles without overlap. , 
Sheldon, in his report, notes evidence that females may peent 
after their eggs have hatched, which may be responsible for the peak 
in singing-ground counts which he had recorded at that time during 
3 years' observations in Massachusetts, and which Blankenship also 
mentions in his report of work in Michigan this year. If this 
