for both mule deer and white-tailed deer in a prairie 

 environment . 



Predictions of fawn survival on our study area could not 

 be calculated soon enough to help set general hunting season 

 structure in Montana. However, predictions were available in 

 time to help establish B-tag levels. The relationship between 

 temperature, precipitation, and fawn survival, although not a 

 precise mathematical tool available at the ideal time, does 

 represent a significant improvement in management capability 

 for early response to fluctuating population/environmental 

 characteristics . 



Existing weather and deer classification data may be 

 sufficient to attempt to establish similar predictive 

 regression models for other areas. Relationships similar to 

 those described by this study and studies of Wood et al . 

 (1989) might be expected for other non-mountainous areas east 

 of the Continental Divide subject to periodic drought. The 

 exact timing of important periods of temperature and 

 precipitation may vary slightly among areas, but should be 

 generally similar. For areas west of the Divide and other 

 mountainous areas, summer-autumn forage conditions are more 

 dependable and drought is less of a problem. For these areas, 

 length and severity of winter may be more important factors 

 determining fawn survival. Although summer-autumn forage may 

 be of consistent quality in these areas, the length of time 

 deer are able to use that forage may vary with the timing of 

 onset and end of winter. Severity of winter would affect rate 

 of fat depletion. 



Predator Management 



It was clear both from direct and circumstantial evidence 

 gathered during this study that predation by coyotes 

 influenced mule deer population dynamics. Other recent work 

 on predation also has indicated that the impact of predation 

 is more than just "removal of those animals that were going to 

 die anyway" (Bergerud 1971, Keith 1974, Beasom 1974, Bergerud 

 1978, Stout 1982, and Gasaway et al . 1983). 



We found that the degree of predation on deer by coyotes 

 was influenced by vegetation and forage production and quality 

 which influenced deer behavior and also levels of alternate 

 prey populations. Certain types of snow and ice conditions 

 also influenced predation rates. In some years and some 

 circumstances, coyotes killed many deer that would have 

 survived in the absence of predation. Predisposition of deer 

 by poor physical condition was not necessary for significant 

 mortality by predation to occur. Similarly, ' Gara and Harris 

 (1988) found that a sample of deer killed by coyotes and 

 mountain lions (Felis concolor) contained more prime-aged deer 



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