PROCEDURE 
The Call-count Method 
Call-count.routes were established after field investigations in 
1950-51 reported by Foote, Peters, McGowan, Kerley, Duvall, Robbins, 
and Wagner (1952). Doves heard calling and doves seen are recorded 
on a route 20 miles in length with listening stations one mile apart. 
Call counts begin one-half hour before sunrise and continue for two 
hours. A report on the call-count method and procedures for randomly 
selecting call-count routes has been published by Foote, Peters, and 
Finkner (1958). Five States - Arizona, California, Florida, Marylend, 
and Virginia - are reorganizing dove survey routes this year. 
The call-count survey provides the only population index 
currently available. It has limitations and possible biases that 
require consideration and evaluation through further study. It is 
an index to the breeding population only and does not indicate pro- 
duction. This is an important limitation because a high percentage 
of the fall population is composed of young of the year. In calcu- 
lating trends in the breeding-population index, doves heard calling 
has been a less variable index than doves seen. Additional research 
is needed to understand the relationship of doves heard calling to the 
actual population in various portions of the mourning dove breeding 
range. Several Cooperative Wildlife Research Units are beginning 
studies of the call-count census method this year. 
Weighting Factors 
To calculate trends in population indexes for units larger than ~ 
one State, the adjusted figure of average doves heard calling per route 
for each State is multiplied by the estimated area of dove habitat in 
the State. Dove habitat area was estimated in the 1958 Mourning Dove 
Newsletter and is listed in table l. 
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 (Kiel, 1959). 
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 nonhunting zones within a management 
unit (table 2). To obtain an average band-recovery rate for a manage- 
ment unit having a hunting and a nonhunting zone, recovery rates for 
the two zones were weighted by the ratio of the breeding indexes of the 
ZONES. 
