ZOPEELETS 
| PELLET 
CONTROL 
Ss SS SS 
0 l 2 3 4 5 6 i 8 
MILES PER DAY 
Fig. 14. -- Number of miles per day averaged by three groups of ducks after they were trapped, banded, 
and released, and before they were shot by hunters, 1950. One group was dosed with a single no. 6 com- 
mercial shot pellet, one group with two pellets, and one group, the control group, was undosed. 
group dosed with one pellet and 58 from the undosed control group. This slight difference in returns be- 
tween the two groups indicates that, entering the 1950 hunting season, almost equal numbers of mallards 
were alive in the two groups. Because of the known greater loss among birds in the dosed group to 
hunters in 1949, fig. 138, a greater difference should have been found in 1950 even though no allowance is 
made for the possibility of additional mortality among the dosed birds as a direct result of lead poisoning. 
Although results are based on but 1 year’s observation, the lead-poisoning loss among birds dosed 
in the 1949 field experiment apparently was inconsequential enough to have been almost completely com- 
pensated for by “normal” losses among the birds of the control group during the period between the close 
of the hunting season in-1949 and the opening of the season in 1950. 
At the present time, for mallard drakes ingestion of not more than one shot pellet by any one bird 
does not appear to constitute an important depressive influence on the population. This is especially 
Significant because most ducks (69 per cent) that swallow lead shot swallow only one pellet each. 
If we can generalize from the above data, we may say that the day-to-day loss of ducks from lead 
SMa 
