Table 1 shows the woodcock area now attributed to each 
State and Province. It is apparent that highly agricultural States 
such as Ohio have been given too much weight in past years. Revised 
figures for the area of each State and Province, and the percentage 
of arable land in each Province were obtained from the 1959 edition 
of the Rand McNally Commercial Atlas and Marketing Guide. The area 
of cropland for each State in 1954 was computed from data in Table 
811 of the 80th edition of Statistical Abstracts of the United 
States, 1959. 
Adjustments for Differing Length of Routes 
Previous analyses have been reported as the number of 
woodcock heard per stop, either with each stop weighted equally 
(which is equivalent to using route totals) or with each route 
weighted equally. It has been shown that both comparisons yield 
approximately the same results in terms of year-to-year change 
in populations (Woodcock Newsletters: No. 1, 1958, and No. 2, 1959). 
Although much may be said in favor of each method, it is believed 
now that the number of birds per route may be more useful than the 
number per stop. Routes with more stops are thought to occur in 
areas of higher population and thus use of number of birds per 
route may tend to weight the data within a State or Province by 
this factor. Adjustment must be made, however, for the fact that a 
few routes do not have the same number of stops each year. Accord~ 
ingly, the number of birds recorded in the year with the larger 
number of stops was decreased in proportion to number of stops. 
For instance, route 36 in Maine reported 6 birds at 6 stops in 
1959 and 6 birds at 9 stops in 1960; for purposes of comparison, 
the 6 birds at 9 stops in 1960 were reduced to 4 birds at 6 stops 
for that year, and a decrease from 6 woodeock in 1959 to 4 woodcock 
in 1960 was used in the analysis. In most cases, as shown in 
Table 2, the necessary adjustments were slight. 
Computations 
For each route covered in both 1959 and 1960, the differ- 
ence in number of birds reported was calculated, always in the same 
direction (1959 minus 1960). ‘The variance of the route differences 
was computed for each State or Province, and multiplied by the sguare 
of the weighting factor (from Table 1) to obtain the weighted vari- 
ance, as shown in the last column of Table 2 for the areas west of © 
and east of the Appalachians. The average change per route for each 
State and Province was multiplied by the corresponding weighting 
factor, and these products were summed to obtain an estimate of the 
