86 
WATERFOWL POPULATIONS AND PRODUCTION ON THE 
ROSENEATH STUDY AREA, SOUTHERN MANITOBA 
1955 
Alex Dzubin 
Introduction 
This report covers the 1955 population and production census for a 
small block of pothole-agricultural habitat in the Newdale - Erickson District of 
Manitoba. The 960-acre study block is situated nine miles south of Minnedosa, 
Manitoba. It contains one hundred and eight potholes, forty-five of which are 
classified as semi-permanent (Bach classification). Most of the temporary pot - 
holes are less than one acre in size while the semi-permanent areas vary from 
one to six acres. Cattail, whitetop, hardstem bulrush, and sedges are the main 
emerpents. 
Weather and Water Conditions 
Break-up was very early this year and most water areas were free 
of ice by April 7. Heavy snowfalls during March, coupled with a very quick run-off 
from April 1 to 3, filled most depressions to overflowing. In over 90 percent of 
the potholes higher water levels were recorded than at any time during the previous 
five springs. 
Mallards, blue-wing teals and canvasbacks arrived on the breeding 
pround a week to 10 days earlier than in 1954 or 1953. The subsequent nesting 
and brood season proved to be at least two weeks earlier than 1954 and could be 
compared phenologically with the 1952 nesting and brood periods. 
Water conditions during the remainder of the nesting season were 
excellent. Heavy rains during May and June added much water to all potholes so 
that water levels rermained far above normal for the rest of the brood season. 
These rains did not appear to interfere with hatching. Very few nests were flooded 
during 1955. In all, precipitation during the summer months was at least 30 
percent above normal. Water levels remained excellent in all brood potholes on 
the study block. 
Breeding Pair Census 
The population of ducks was censused every week. The maximum 
number of any species observed during any one census period in May has been used 
as the breeding population for that species. A definite number of pairs of each 
species was then assigned to each quarter section. 
