of young produced. Low (1945) found that the production of redheads on 
breeding areas in Iowa was 398 flying juveniles for 100 nests. Stoudt (1938) 
was able to estimate the number of waterfowl produced on the Chippewa 
National Forest of Minnesota by means of careful brood counts, 
6. Classification of water areas. Since an understanding of preferences 
of young and adults is partly dependent on the observer's ability to arrange 
water areas in groups with conmon characteristics, a system mst be devised 
for classifying them. The classification used and developed in the present 
study is based on the physical characteristics of the water areas as they 
relate to waterfowl use and to plant succession, Those areas are grouped 
together which have common features judged to be important from this standpoint. 
II. THE STUDY AREA 
General Descriptien 
Location -= The first of two summers devoted to this project, the summer 
of 1948; was spent at the Delta Waterfowl Research Station at Delta, Manitoba, 
working on a technique for marking young birds for identification and 
observing the habits of broods (Evans, 1951). The summer of 1919, June 12 to 
September 3, was spent near Minnedosa, Manitoba, 80 miles west of Delta, where 
the field work described in this report was carried out. 
Geol -=- This area is over 1,600 feet above sea level and is overlain with 
a thick layer of glacial till derived from the granites of the Laurentian 
shield and limestone from the district of lakes Maniteba and Winnepeg, mixed 
with shale from the nearby underlying strata (Ellis, 1938). The surface is 
somewhat rolling; uplands are usually well drained. Depressions are filled 
with water from melting snow and frem rains and form water areas varying from 
small temporary puddles to ponds of 10 acres or more, The soils of the 
region are northern black earths which are predominantly clay loams formed 
under tall-grass prairie follewed by aspen groves, 
Climate -- The average anmual precipitation for the peried frem 1885- 
189 as given by Bird (1930) for the aspen parkland varied from 18.80 inches 
at Winnipeg te 17,38 at Fort Ellice and 17.1) at St. Albans. The distribu- 
tion at Fort Ellice was as follows: winter (December, January, February), 
2.1 inches; spring, 3.65 inches; summer, 8.30 inches; and fall, 3.02 inches. 
The greatest anount fell in June, 
Currie (1948) describes the vegetative season as the peried in which 
the mean daily temperature is at least 2° F, and the minimum at least 32° F, 
For the region of Minnedosa, this period begins the second half of April and 
ends the first half of October. 
During 1919 water levels were generally high, A partial record from the 
Minnedosa weather station shows that the precipitation was 15.30 inches for 
the vegetative season. Two rainstorms which greatly affected the area during 
the study occurred on July 20 (1,3), inches) and July 28 (2.93 inches), These 
replenished the surface waters after a relatively dry June and early July. 
Land Use -- The study area included about 976 acres or 14 square miles, 
of which about 560 acres (57 percent) were under cultivation, producing 
mainly wheat and barley, with some oats, and 140 acres (1) percent) were 
used as permanent pasture. In 199, augmented by spring and fall grazing 
of cultivated areas, the pastures supported 36 cattle and 11 horses. During 
