The available data did not indicate any consistent 

 pattern of better fawn survival for one grazing system over 

 the other or one grazing treatment over the others within the 

 rest-rotation system (Table 9.7). The data indicated higher 

 fawn survival during spring 1984 and 1985 within the rest- 

 rotation system. However, those data were collected 1-2 

 months earlier than on the season-long grazing system and 

 mortality continued through the period, at least within the 

 continuous grazing system. Subsequent population estimates 

 (Figure 9.10) indicated that fawn survival probably also 

 declined within the rest-rotation system after the aerial 

 survey, especially during 1985. Annual changes in fawn 

 survival appeared to be more similar than different between 

 the 2 grazing systems and appeared related more to common 

 environmental influences than to differences in grazing 

 systems . 



Table 9.7. Fawn: 100 adult ratio during spring for mule deer inhabiting a 

 rest-rotation grazing system and a season-long grazing system 

 in the Missouri River Breaks, Montana. 



NCRCA (Rest-rotation) South-side Study Area 



Year Pasture 3 Pasture 4 Combined Season-long Grazing 3 



Spring 



11 



30 

 26 

 65 

 82 

 61 

 44 

 59 

 13 

 5 

 18 

 65 



Season-long grazing, April 15 - November 15. 



H = Heavy use April - August. 

 R = Pasture rested entire year. 

 V = Pasture used June - November. 

 S = Pasture used August - November. 



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