
The prairie breeding area 
The waterfowl breeding grounds on the prairies of southeastern 
Alberta, southern Saskatchewan, andi southwestern Manitoba are con- 
fined mainly within a block bounded on the north and south by the 
latitude. lines 99 and 5° North and on the east and west by the 
longitude ines 98° and 114° West. Within this block the habitat 
has been divided into strata for the purpose of more efficient 
sampling when conducting the aerial breeding-population and produce 
tion surveys. Stratification was based on differences in the 
variability characteristics of the data, which is generally related 
to population density, and on the relative importance of each 
stratum as measured by the size of the population present. 
Figure 1 shows the general location of the strata; the follow~ 
ing list gives the area and genera] habitat type of each stratum: 
| Square miles 7 Habitat type 
Alberta: | 
Stratum Acececes 22,088 Tall-egrass prairie, 
Stratum Beoecsce 26,100 Parkland. 
Stratum Cocccene 16,112 Short-grass prairie. 
Total. cccccce| 6),, 300 | 
Saskatchewan: 
— Stratum A-iest.. 36, 630 Tall-grass prairie, 
Stratum A-East.. 1,600 Parkland. : 
Stratum B-West.. 20, lik8 Parkland. 
Stratum B-Eastee 30,072 Parkland. 
Stratum Coaccces ll, 290 Short-grass prairie, | 
 Totaleccescee 113,00 
Manitoba: 
Stratum Aeccesce 10, 368 Parkland. 
Stratum Besesece 28 ,600 Parkland. 
Total. .ecosce 38,968 | 
Grand Totalee 216, 308 

