
deserted this year those very marginal and undependable grassland habitats 
the species prefers. All other species seem to be reasonably secure in the 
more durable grassland habitats. and in the parklands. 
Production Indices 
With the 1957 breeding population being slightly less than 
in 1956 it was interesting to find a 45.9 percent increase in the broods 
per square mile observed this year (5.4} as compared with last year (3.7). 
All of the strata are up but stratum B-East showed the greatest percent 
increase in broods observed per square mile (88 percent). In the 
Saskatchewan grasslands and western parklands, Class II and III broods 
predominated but Class I's were also common. The hatch in the remainder 
of the survey area was slightly later, but all three age classes of broods 
were present in about equal proportions. 
This year's production pattern is somewhat similar to that 
of 1952, namely. there was an excellent early hatch with little re-nesting 
or late nesting taking place. This situation is in direct contrast to the 
record breaking 1955 season in which re-nesting played such an important 
part. The 1957 late nesting index is the lowest since 1951, This 1s cer- 
tainly little cause for worry because it looks.as if most of the ducks were 
satisfied with their first attempt and turned out quite a crop of ducklings. 
| It 1s of interest to note that on the Redvers Ground Study 
Area in soptheastern Saskatchewan there was a definite decrease in the 
production of all species except mallard and pintail. The area was 
exceptionally dry. however and may not be typical. 
\ 
Table 3 - Summary of Air Data ~ July 1957 - South Saskatchewan 

Strata 
.East A. West B-East B-West G Province 
See oe te = oe ee ee ee 
Broods Per Sq. Mi. 5.811 4.265 8.027 4.122 2.272 5.400 
Brood index 84.840 160 492 280 965 63.891 25,651 615,839 
PLB Per Sq.Mi. 2.334 2875 - 898 -500 -208 «952 
Late Nesting Index 34.076 32 926 31 448 7,750 2.348 108.562 
Ponds Per Sq.Mi. 27.634 6.650 12.985 7.108 3.136 10.996 
Pond Index 403 456 250.240 454 735 110,174 35.405 1,254,010 
Coot Brood Per 
Sq. Mule -599 1.247 4.904 1.540 256 ~ “ 
Coot Brood Index 8,755 46 925 171.738 23.870 2 890 254,178 
48 
