
method used by We Ee De Halliday in his "A Forest Classification for 
Canada," Ottawa, Canada, 1937. Stratum C, the semi-arid prairies of 
extreme southern Alberta, is characterized by a short-grass plain, the 
northern extension of the Upper Sonoran Life Zone, Stratum A, which 
extends roughly from the latitude of Lethbridge to Red Deer is made up 
of the mixed grass prairie, with a higher annual precipitation than the 
stratum to the south. In Stratum B, the parklands, we find a tran- 
sitional zone, where an interspersion of aspen and grasslands give a park- 
like appearance to the countryside. This major Alberta waterfowl area 
comprises 65,000 square miles and is bordered on the west and north by 
the closed northern coniferous forest, Stratum D. 
The rail studies discussed here were made only on special study 
areas within Stratum A and B, during the period from May 1 to August 1, 
1953 and 1954. The two study areas in Stratum B, the parklands, were 
located in the northeastern and the southwestern edges of this vegetative 
type. The study area in Stratum A was located east of Calgary in the 
west-central portion of this particular stratum. 
The method used in collecting rail population data in 1953 was to 
approach each pothole, toss a few rocks into the center and/or the edges 
and wait for the rails to make their loud and distinctive "keek,"” Later 
in the season, after the broods are moving about in the marsh, it was also 
possible to count numbers of broods, if not brood sizes, as the young have 
a decidedly different cry than does the adult. Because of the time element 
involved and.the poor success resulting, little effort need be made to 
count sora rail in early May as they prefer to remain silent when disturbed. 
If time were of no account, long hours of waiting at each area would, how- 
ever, result in an observer being able to record their spring 'song'. 
In 1954, less effort could be expended on this study, but on the two 
parkland study areas, counts of rails were made by the ground crews while 
taking regular waterfowl population and brood counts of each water area, 
Results 
Utilizing the method described above, it was surprising how consistent 
the population densities of rail were in both parklands and prairies in 
1953. Small potholes invariably contained one pair each, larger areas two 
or three. Lake shores seldom attracted them. Later in the seasan, as 
smaller areas dried, there was an apparent movement of adults and young from 
these areas to those containing water, 
During the period of breeding activities, laying and incubation, but 
prior to the hatch, the average population density of sora rails per pothole 
in both Stratum A and B was one pair per pothole, Aerial and ground surveys 
of both prairies and parklands have shown our study areas to be represent- 
ative samples of the vegetative stratum in which they are located. 
Fluctuations of waterfowl populations on these study areas have also been 
generally consistent with fluctuations in the entire stratum. If for the 
sake of argument we can assume for purposes of this report, that these areas 
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