113 
Table I - Total Water Bodies on Areas ‘1, 2 and 3 to height of Nesting Season* 

Date Area | Area 2 Area 3 
May 6 121 148 84 
May 13 125 140 82 
May 18 116 126 80 
May 27 80 105 76 
June 4 72 89 72 
Percent decrease 40,5 39.8 14.3 
*Provincial loss of water May 1-July 1 - 26.75 percent 
Parkland loss of water May lI-July 1 - 30.15 percent 
Table II - Pothole Classification - Areas 1, 2 and 3 -- May 6-June 15 
Area I Area 2 Area 3 
Type May 6 June 15 May 6 June 15 May 6 June 15 
A-permanent 54 33 30 35 60 53 
B-semi-permanent 39 17 65 33 13 17 
C-temporary 28 22 53 21 11 2 
Total 121 72 148 89 84 72 
Areas 1 and 2 suffered water losses exceeding the Provincial (26.75 percent) 
or parkland (30.15 percent) average for the same period. Area 3 reflects the 
abundance of rainfall in that area by a loss of only 12 areas or 14 percent during the 
nesting period. 
In former years the size of the area in Alberta where waterfowl populations 
have been under study (64, 300 square miles) was far too large to allow for repeated 
observations of changes in the population throughout the season. By the establishment 
of small study areas and the assignment of full time observers to these areas, records 
were kept this year at weekly intervals from May through July. It is difficult to know 
with certainty that aerial sampling of breeding populations is made at the ideal time 
when the greatest number of species are settled down to the task of nesting. By making 
weekly checks at specific locations, we can learn both the phenological condition of the 
waterfowl populations in those areas and how well the date selected for aerial coverage 
has coincided with the maximum populations present. The most pronounced shift 
occurred in mallard populations. Early changes may result from late arrivals but 
those occurring after May 15 could be accounted for by the loss of early nests to 
agricultural activity. This is particularly true in the district around Areas 1 and 2 
where farmers were able to plow their stubble earlier than in much of the Province 
because of the prolonged dry period from April through mid-June. 
From 1947 to 1951 the breeding season in the northern parklands has been 
about two weeks later than that on the southern prairies. This year, with the entire 
area opening up at once, nesting began at the same time throughout all of southern 
and central Alberta. 
