Birds were seen and heard on singing grounds during snow, rain, 
and heavy winds. On the nights of snow or rain the activity seemed 
rather normal during the first part of the usual time period, but all 
activity stopped much earlier than on a clear night. On windy nights 
the birds seemed as active as ever, but hearing distance of the "peents" 
was greatly reduced. 
Vegetation and topography seem to determine the distance at which 
peents may be heard. Heavy vegetation and rolling topography often 
provide a barrier for woodcock sounds. Therefore, there seems to be 
no possibility of overlap in making counts at 0.4 mile apart. Probably, 
if it were desirable, the distance could be reduced to 0.3 mile. At 
least if a complete count of all the birds along a certain route was 
wanted the distance would probably need to be shortened. 
Table 15 illustrates the regularity of singing ground occupancy . 
by male birds. It is noticeable that on the Rose Lake route where the 
population fluctuation was relatively small during the breeding season 
most of the grounds were occupied more than 50 percent of the time. On 
the Gratiot-Saginaw route, where population fluctuations were more pro- 
nounced, most of the singing grounds were occupied less than 50 percent 
of the time. The latter area provides more woodcock cover; therefore, 
the singing birds may have had a tendency to move more frequently. Sing- 
ing ground areas and diurnal cover are more restricted along the Rose 
Lake route. | | 
Table 15.--Regularity of singing-ground occupancy by male birds 
Number of birds heard 
ute Eee 7 9 
Rose Lake 2 Loe 3 
Gratiot-Saginaw 0. 194 2926 ok 

Most of the woodcock survey data acquired during the period of 
June 21-September 7 have not been analyzed. However, a part of the 
data on summer habitat types used by Michigan woodcock has been sum- 
marized (table 16). These data show that a high percentage of the 
birds was flushed from alder or aspen cover or a combination of cover. 
with either or both aspen and alder present. Most of the sites were 
moist or slightly wet. No woodcock or wodcock sign was observed in 
the drier upland associations of various vegetative types. 
h7 
