. California fish and game. Fisheries -- California; Game and game-birds -- California; Fishes -- California; Animal Population Groups; Pêches; Gibier; Poissons. 116 CALIFORNIA FISH AND GAME 2. Determination of the most feasible and economical plan of har- vesting beaver with employed trappers, 3. Types and use of equipment necessary for the successful opera- tion of such a plan. 4. Methods of marketing to obtain the greatest monetary returns. 5. Determination of occurrence of disease in Colorado Kiver beaver. 6. Collection of weights and measurements of adult J<'niiii(i'; :;n. iVl
. California fish and game. Fisheries -- California; Game and game-birds -- California; Fishes -- California; Animal Population Groups; Pêches; Gibier; Poissons. 116 CALIFORNIA FISH AND GAME 2. Determination of the most feasible and economical plan of har- vesting beaver with employed trappers, 3. Types and use of equipment necessary for the successful opera- tion of such a plan. 4. Methods of marketing to obtain the greatest monetary returns. 5. Determination of occurrence of disease in Colorado Kiver beaver. 6. Collection of weights and measurements of adult J<'niiii(i'; :;n. iVlirst of iliii .survey was performed in small boats powered by outboard motors Methods The first joint survey of the Colorado River beaver was undertaken in September of 1943 and thereafter in October for the four subsequent years. The initial procedure involved crisscrossing the river from bank to bank wherever the channel permitted, making counts of beaver lodges or houses, freshly used beaver slides, beaver bank burrows, beaver scent mounds, and general observations. The recording of beaver bank burrows excavated in the stream banks was attempted during the first three surveys and thereafter discontinued. It was found that these counts could not be made with anj^ degree of accuracy because of almost daily water level fluctuations due to controls exercised at Boulder Dam located approximately 60 miles above the upper boundarj^ of the study. These counts, consequentlj^ were of no value for comparative analysis in attempting to measure beaver population density in the river. Due to frequent blockage by sand bars during low water periods of the day, it was difficult to obtain counts of the beaver slides at such sites. It is estimated that Table 1 represents about 40 percent of the total number of the beaver slides and 80 percent of the beaver houses present in the river for, theoretically, only 50 percent of the beaver slides would have been observed and counted by the method us
Size: 2612px × 957px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorcaliforniadeptoffishandgame, bookauthorcaliforniafish
