WHITE PELICANS 



White pelican (Pelecanus erythrovhynchos) studies included aerial 

 censuses and some food habits analyses. In addition, pelicans collected or 

 found dead on the river were checked for federal leg bands. Bands thus 

 obtained were sent to the Migratory Bird Populations Station in Patuxent, 

 Maryland. 



OTHER MIGRATORY BIRD STUDIES 



Other large migratory birds, shorebirds, and piscivorous species were 

 observed on occasion. Notes on their feeding habits, distribution, and time 

 of year observed in the study area were recorded. 



ISLAND AND VEGETATION ANALYSIS 



Aerial photographs taken by the Montana Department of Highways were 

 used in an analysis of selected aspects of the river vegetation and channel 

 morphology. The photographs utilized were color prints approximately 

 9X9 inches in size, scaled to 1:24,000, with approximately 50 percent 

 overlap. The photographs from Billings to Fairview, Montana, were 

 divided into groups corresponding with the sections into which the flight 

 data were divided. 



All parameters to be studied were traced on plastic overlays; cover 

 types along the shoreline (dense cottonwood, cottonwood-grassland, sagebrush- 

 grassland, shrubs, cleared for grazing, agricultural, breaks, industrial 

 and housing, and gravel bars) were coded by color. All island cover types 

 were color coded according to the same scheme. 



Areas of vegetation types, lengths of shoreline per vegetation type, 

 island sizes, and thalweg lengths were measured with a digitized planimeter. 

 Sinuosity was later calculated by dividing the thalweg length by the 

 straightline distance between the midstream points at the upstream and 

 downstream ends of each section (the down-valley distance). Other parameters 

 measured were the total water area, total shoreline length (the wetter 

 perimeter), and the total gravel -bar area. Results of this analysis are shown 

 in appendix C. 



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