Weighting Factors 
When banding effort is not proportionate to the size of the 
breeding population in the different States or regions, weighting 
factors are necessary to allow comparisons. For example, we 
used 39 band recoveries from doves banded in Massachusetts, a 
State with a relatively small breeding population, and 2 band 
recoveries from doves banded in Montana, an important dove- 
producing State. In order that band recoveries from the less 
important areas do not overshadow the recoveries from more 
important areas, it is necessary to weight the data prior to 
analysis. Weighting to eliminate disproportionate banding effort 
was accomplished by dividing the dove breeding-population index 
for a State by the number of doves banded (table 3). A State 
breeding-population index was estimated by multiplying the square 
miles of dove habitat in the State by a mean dove-density index 
that was based on data from call-count surveys conducted over a 
4-year period, 1954-57. 
In calculating band-recovery rates for local, immature, 
and adult mourning doves on a management-unit basis, the 
breeding-population index for a State was divided by the number 
of doves banded in each age group to obtain a weighting factor 
for each banded bird. Band-recovery rates on a State basis were 
calculated only for those States banding 100 or more doves in the 
age group of interest, and only those States were included in the 
calculation of weighted band-recovery rates for hunting and for 
non-hunting zones within a management unit (table 7). 
To obtam an average band-recovery rate for a management 
unit having a hunting and a non-hunting zone, recovery rates for 
the two zones were weighted by the ratio of the breeding indexes 
of the zones (table 8). 
Assumptions Underlying the Analysis 
Emphasis in this report should be on the word preliminary, 
for the assumptions underlying the procedure of weighting mourning 
dove banding data are not well understood. Ina general sense, 
three assumptions are necessary to validate this analysis: (1) Banded 
birds represent the breeding index of a State or management unit; 
(2) the breeding index represents the same proportion of the actual 
population in all management units; and (3) there is a uniform rate 
of reporting bands found on shot birds. 
