Interesting, too, is the fact that with openings on Octo- 
ber 1 to 3, redheads, although rare in the population, had a 
vulnerability rating of 3.45 compared with a rating of 0.65 in 
the period 1959-60 and to a rating of 0.88 for the entire period. 
Crippling loss 
Crippling loss data are available for the last 9 years of 
the period. It was found that for the entire area, the average 
crippling loss amounted to 15.37% of the total kill. (Cripples 
and bagged birds were added together, then the percentage of 
cripples to this total figure was determined. Thus, crippling 
loss as here shown indicates the percentage of the total removal 
of birds and not a relation between birds bagged and birds lost.) 
Crippling loss varied greatly between the various areas 
checked, with the highest loss recorded at Keithsburg, followed 
by Upper Mississippi, Batchtown, Louisa, Calhoun, and Gardner. 
It is felt that perhaps the data from Keithsburg are not enough 
to mean much and should be viewed in this light. 
Table 26 compares percentage crippling loss to other facets 
of the hunt. 
Table 26 - Comparison of Crippling Loss and Hunter Success 
Percent Crippling Hours Hunted Av. Ducks 
Refuge Area Loss Per Duck Bagged Per Day 
Upper, Mississippi 20.94 | 3.94 1.23 
Louisa 13.20 Tie Te ae 1.37 
Keithsburg 25.27 5.72 -76 
Gardner 6.34 7.35 69 
Batchtown 13.65 4.98 1.37 
Calhoun 10.57 6.37 ~ 90 
If Keithsburg data are dropped from this table, it will be 
noted that as the crippling loss goes down the hours required per 
duck go up. This suggests the possibility that in an area where 
it is easier to bag a duck less time might be spent in searching 
for a downed bird than is the case where ducks are harder to get. 
Although not indicated in this overall summary, records from 
the Upper Mississippi Refuge show that crippling Losses are higher 
north of the Wisconsin River than south of there. This could well 
be influenced by cover conditions in the different portions of the 
refuge. As previously discussed, the best marsh development occurs 
Th 
