Results 
Nestinz Pairs - Production 
The results of the 1949 season waterfowl production survey ars presented 
in Table 2. In ¢srtain of these rezions coveracse la at present inadsquats since 
priority in time and personnal has besn dayoted to the more important arsus, 
Wherever possible, production figures have besn based on 1948 and 1949 seasons 
nesting studise and trood count data, Where such data wars non-sxistent figures 
from compe-cble arecrs hays been used. [Sas Table 2} 
Comparatle data on 1948 and 1949 asrial transect stripa flown at agprozi- 
mately the same dato sach year with the same observers 18 ayailatls on ths Graas- 
land area, This arsqa in the San Joaquin Valley is a natural unit of land 
devoted to ¢cattls raising on flooded alkali pastures lands and privately ovwmed 
min clubs. Results of thess two csnsuses are shown in Table sntitled "Grasslands 
~ Asriel Transsct Data". 
Comparison of thess figures indicates a significant incresss in breeding 
dueks for this area. Tnis, as well as other data not imeywlced, indicates that 
Such was actually the case, however, sings ths amownt of water relisased on thes 
arsa waa proator in 1949 than in 1948 and the fact that this water is artificially 
manipulated, this increase cannot ba applied to the region or the Stats as a 
wholes. Stated simply, such trends ¢annet bs reliably used of areas where water 
eanditions are subject te artificial manipulation, 
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