
186 
Adult Juvenile Ratios 
Table 5 illustrates adult-juvenile ratios for all ducks seen on the census. 




Table 5, ~- Adult - Juvenile Ratios - 1950 
Species Adults Juveniles Ratio 
Mallard 177 585 1 to 3,3 
Baldpate 118 405 1 to 3.4 
Golden-eye 114 189 1 to 1.7 
Blue-winged teal 19 47 1 to 2.5 
Ring-neck 28 47 ltol1.7 
All others 14 22 1 to 1.6 
Total 463 | 1295 102.7 
The ratio of adults to juveniles for all species for each year of the census 
is as follows: 
1937 1938 1939 1940 1941 1947 1948 1949 1950 
1:3.0 1:2.2 1:3.4 1:1.5 1:2.7 1:2.2 1:4.0 ---- 1:2.7 
A fact to take into consideration in the above data is that very few molting 
drakes are observed on the census so that most all of the adults include; maternal hens, 
pairs, and lone drakes or hens which can still fly. 
From Table 5 we could conclude that breeding success as measured by the 
ratio of juveniles to adults was at least average. 
Summary 
In conclusion the following points seem pertinent: 
1. Extremely high water levels on certain census areas caused some 
broods to be missed, so total estimate must be revised accordingly. 
2. Raw data shows a 15 percent decrease from 1949 and 46 percent 
decrease from the average for 1939-40. Revised estimates based 
on areas unaffected by high water would place the waterfowl +. 
population at about the same as for 1949 and only about 20 percent 
under the 1939-40 figures. 
3, Mallard and golden-eye continue at about the same relative 
abundance with baldpate showing a steady increase since 1940. 
Blue-winged teal were almost out of the picture. 
4. Brood averages were slightly below the nine year average. 
5. The ratio of juveniles to adults indicated at least average 
breeding success, but itis considerably lower than the 
1948 figures. 
