173. 
WATERFOWL BREEDING GROUND SURVEY IN COLORADO, 1953 
Jack R. Grieb, Harold M. Boeker, John R. Tester, 
Erwin L.. Boeker and Ladd G, Frary * 
Introduction 
As in past years, the Colorado Game and Fish Department has apain cooperated 
with the Fish and Wildlife Service in determining the status of waterfowl in Colorado. 
This is the first year of a proposed 5-year waterfowl plan which, it is hoped, will 
eventually place all waterfowl nesting areas in the State under control. Thus, we may 
deliver the results of our surveys to the Fish and Wildlife Service in terms of estimates 
of total breeding-pairs and production for Colorado. Previously such reports gave only 
trend results, and converting to the new method has involved a great deal of change in 
thinking, planning, and setting up the correct type of sample routes to effect such 
conversion. Despite this, some progress has been made toward the final poal, so that 
we are now able to give total production estimates for 6 of the 8 major breeding areas 
in Colorado, 
This final report, therefore, cannot give total State breeding-pairs and production 
for all areas. It will include totals of those areas for which they are available, and 
give general results for all other areas, 
Methods and Study Areas 
Survey methods used in 1951 and 1952 were retained in 1953, except where 
physiography and size of area necessitated modification. Thus, the general procedure 
was determination of the breeding population and, later, production, chiefly by 
breeding -pair and brood counts on randomly selected samples for all breeding grounds 
surveyed. The data so obtained have been used in estimating total breeding populations 
and production. 
A summary of sampling methods and areas is given in Table I. 
Weather and Water Conditions 
Climatological data and phenological records indicate that Colorado experienced 
a mild, dry winter resulting in smaller accumulations of snow in the mountains this 
year. Run-off, when it did occur, was about two weeks later than normal and much © 
reduced. The effect on waterfowl, especially on the western slope was twofold: 
(1) the birds could not reach their usual nesting areas in the higher elevations until 
later, because of the late storms and delayed run-off; (2) there was little flooding, 
and consequently fewer destroyed nests resulting in a smaller number of birds 
renesting this year. . . 
* Grateful acknowledgement is made by the authors to Dr. Lee E. Yeager, Leader, 
Colorado Cooperative Wildlife Research Unit for valuable suggestions and 
cooperation; and, to Boyd Evison and Norman L, Hughes, who assisted in the 
collection of data. 
