
116 

Gray Lodge - Tobin =Fenn Sartain TOTALS 
1949 1950 1949 1950 1949 1950 1949 1950 
Pps EAs SAS KE Sc A A Ra ec DN HEI ae Ph Sea nic 
Average Clutch Size 
of Successful Nests 
Species - Mallard 8.8 8.8 8.3 8.2 7.8 8.4 8.3 8.4 
Gadwall 11.3 10.6 9.8 11.0 10.0 --- 10.8 10.7 
Cinn,. teal 9.1 9.7 10,1 9.7 8.5 10.0 9.5 10.5 
Average No. of Eggs 
Hatched in Successful 
Clutches - Mallard 6.4 8.7 7.8 z 7.5 
Gadwall 8.9 9. 0* 8.5 12, 0* 8.0 -<-- 8.7 10.5 
Cinn,. teal 8.3 9.0 9.9 7.8 8.3 10.0 8.9 8.6 
* 1 nest 
xx 2 nests 

Clutch size for mallard and gadwall have been constant for both years. 
Increase in clutch size of cinnamon teal is probably due to the relatively small sample. 
The average number of eggs hatched in successful clutches for mallard and gadwall 
shows a slight increase but perhaps is of no significance. 
Information relative to date of hatch in the Sacramento Valley is difficult to 
obtain by methods other than nest observation. Brood observations are difficult to 
gather on a large scale due to heavy cover in growing rice fields. Based on nest 
observations, date of hatch in this area was determined to be as follows: 
Date of Hatch - Sacramento Valley 
Percent Nests Percent Nests 
Week Period Hatched - 1949 Hatched - 1950 
April 21-30 5 ~ 
May 1 - 7 2 - 
May 8 - 14 7 8 
May 15 - 21 2 6 
May 22 - 28 5 12 
May 29 - June 4 28 14 
June 5 - 11 33 42 
June 12 - 18 9 12 
June 19 - 25 7 2 
' June 26 - July 2 0 0 
July 3 -.9 3 2 
July 10-- 16 0 2 
al 
1949 - Data based on 58 nests of known date of hatch. 
1950 - Data based on 50 nests of known date of hatch. 
For the past two years the peak of the hatch has occurred during the first 
half of June with almost 70 percent of nests hatching between the dates of May 29 and 
June 18 in the Sacramento Valley. 
