
“peenting" birds expanded from counts on both types of routes. 
These population values are "indexes" because all "“peenting" 
birds probably were not heard when numerous birds were per- 
forming at a stop, or when extraneous noises reduced effi- 
ciency but did not eliminate hearing. Population indexes were 
obtained as follows: 
Average number of peenting birds per stop x Total sq. miles 
pi ee (wnere + 1250129 in each stratum 
Population indexes indicated by "peents" and "flight songs" 
combined are not shown because the aerial call can be heard at 
a distance greater than 0.2 mile. 
As shown in table i population indexes indicated by counts 
on operational routes were much higher than those calculated 
from random routes. Furthermore, population indexes based on 
operational counts were nearly equal in both portions of the 
Lower Peninsula. In contrast, the population index from 
random routes was nearly twice as large in the northern Lower 
Peninsula as in the southern. The difference in population 
indexes indicated by the two types of counts was caused by 
the higher average number of birds per stop recorded on oper- 
ational routes, and occurred because most operational routes 
were selected in areas known to contain woodcock. 
Population sizes indicated from counts made on random 
routes probably are much more representative of actual popu- 
lation size than are counts made on non-random operational 
routes. Although the population figures from random counts 
are indexes, they can be compared with values obtained in 
Similar manner in later years and in other areas. 
The same routes will be covered again in 1964. With 
2 years of data, it will then be possible to compare the 
relative size of the population and the relative change in 
woodcock numbers from 1963 to 1964 on both random and oper- 
ational routes. 
or 
