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RIVER STUDY SECTIONS 



To simplify organization of collected data and to facilitate presentation 

 of findings, the portion of the river studied, beginning at Billings and 

 ending at Fairview, was divided into 21 study sections, shown in figure 1. 

 These study sections were helpful mainly in the Canada goose and dabbling 

 duck studies. 



MAJOR BIRD STUDIES 



CANADA GEESE 



Aerial Censuses 



Canada goose populations along the lower Yellowstone River were counted 

 at irregular intervals depending on the time of year, migrations, and weather. 

 Flights were conducted with a Piper Super Cub (PA-18) from Miles City to 

 Billings on one day and from Miles City to Fairview on the next that weather 

 permitted. Because geese sometimes loafed away from the river at midday 

 from late fall through the spring migration, censuses taken during that 

 period sometimes required flying over parts of the valley away from the 

 river. 



Observations of field-feeding geese were recorded at all times of the 

 year except during the flightless period. Records were kept of the type of 

 field used, number of geese in each flock, field condition, and time of day. 

 In addition, after neck bands had been applied to resident birds in 1975, 

 field-feeding flocks were closely scrutinized to locate neck-banded individuals. 

 All recorded observations of such birds were plotted on maps for calculation 

 of the sizes of the birds' seasonal home ranges. 



Nest Surveys 



Surveys of nesting Canada geese were conducted through the springs of 

 1975 and 1976. Selection of study sections was based upon the availability 

 of boat-launching sites at their downstream ends. In 1975, nesting surveys 

 were conducted in the Bighorn-to-Hysham, Hathaway-to-Miles City, Miles City- 

 to-Kinsey (upstream from the mouth of Sunday Creek only), and Fallon-to- 

 Glendive sections of the river. The downstream ends of these areas were 

 searched first; areas upstream were checked only as time allowed. Nest 

 searches in 1975 were ended when eggs began to hatch. In 1976, they were 

 ended when excessive desertion occurred between the weekly-to-biweekly 



