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Because aerial flights are limited by time and weather conditions, it is 
not always possible to make observations at a period corresponding with the 
greatest build-up of waterfowl populations throughout all of Alberta. The breeding 
population figures for the Province are now based on aerial observations. Therefore, 
it is of interest to know the condition of the observed population on the flight dates. 
The breeding population count was made on Areas 1 and 2 on May 22, on Area 3 on 
May 18. We now find that in study Area 1 we were one week late in sampling the 
peak population. On Area 2 the difference between the population density on the 
date of the aerial flight and one week following was very small and for practical 
purposes it could be said that we sampled the peak population at the correct time. 
Aerial sampling on Area 3 was one week early though the peak on the following week | 
was not very much greater. 
Nesting Studies 
Each of the observers spent a considerable amount of time searching for 
waterfowl nests throughout the period of the study. These searches are always 
rewarded to a greater degree on the prairies where cover is less dense. Two wet 
years in succession provided a maximum cover density in the parklands this year 
which lessened the success of the searches. Then, too, nests are more easily 
located in known nesting marshes of considerable size. On the study plots, water- 
fowl habitats are composed of scores of very small water bodies with continuous 
large acreages of densely vegetated ground surrounding them and extending for 
miles in all directions. A condition like this intensifies the problem of finding the 
fewer nests which are scattered over vast acreages. 
On the basis of the information obtained by these nesting studies, 69 percent 
of the waterfowl nests located within 1/8 of a mile of a highway hatched successfully 
on Areas 1 and 2. Only 50 percent of the nests located at distances greater than 1/8 
of a mile from a highway were successful in the same districts. In Area 3, 
42 percent of the nests close to highways were successful while only 33 percent of 
those located over 1/8-mile from a highway were brought off successfully. These 
results are at variance with a preconceived idea that highways tended to lessen the 
hatching success. The information available here is still of minor importance when 
total breeding areas are considered but it would seem at least possible that "highway 
interference" if any, works to the advantage of the ducks in keeping predators ata 
safe distance, for predator loss mounted as the distance from a highway approached 
1/4 mile or more. 
Particular care was taken by observers making nest studies to create the 
minimum of disturbance at a nest site. However, itis felt. that the human element 
is a very important factor in causing nest losses, especially in the case of upland 
waterfowl nesters. No amount of precautions at the nest or in searching for it can 
eliminate the human spoor from an area which has been criss-crossed by men 
searching for nests. Coyotes, skunks, and dogs will all follow a man's trail. Crows 
and magpies will actually watch a man's actions in the field. After an observer has 
left the site of a nest where he obviously will spend a few moments making proper 
recordings, both crows and magpies will fly to that nest site to investigate. A 
constant repetition of predation on nests in Area 3 and the surrounding district 
immediately after the first discovery of a nest, leads one to question the accuracy 
of our findings based on the unnatural bias of human interference. 
