temperature) as for fawn survival to December, but less of the 

 variation was explained. Again, neither variables relating to 

 deer density or winter severity added significantly to the 

 regression. We expected current winter severity to play a 

 greater role in determining fawn survival through spring, but 

 the effect of winter severity was apparently not consistently 

 linear. Instead, it acted catastrophically during some years 

 and inconsistently during others. 



An underlying relationship appeared to exist during most 

 years between fawn survival to December and variables for 

 precipitation and temperature prior to birth. Because there 

 was no relationship with deer density or lag effects of 

 density, it is doubtful that the relationship we observed was 

 related to forage quantity . Fawn survival should not have 

 been directly related to forage quantity only, but to relative 

 forage quantity as influenced by deer density (forage per 

 capita) . 



We believe the relationship of July-April precipitation 

 and mean May temperature with fawn survival was one of forage 

 quality to fawn survival, rather than forage quantity to fawn 

 survival. Forage quality was not measured directly; only 

 general observations were recorded. Based on the literature 

 (Mackie et al . 1979, Short 1981, and Wallmo and Regelin 1981), 

 we assumed that forage nutritional quality was highest in 

 growing plants and declined at and after plant maturation. 



Blaisdell (1958) found that phenological development was 

 correlated with temperature and precipitation during the 

 growing season. He stated, "Early in the spring, phasic 

 development of plants is controlled chiefly by temperature, 

 but later in the season temperature becomes less important and 

 development is hastened by a shortage and retarded by an 

 abundance of moisture." Wielgolaski (1974) and White (1979) 

 also indicated that temperature was very important in 

 determining plant phenological development. When spring 

 temperatures were high, plants grew and matured faster, 

 reducing the time that they provided quality forage, and 

 reducing their total yield. The same temperature and 

 precipitation variables correlated with increased yield also 

 were correlated with delayed plant maturation and a longer 

 period of quality forage (Blaisdall 1958). That relationship 

 agreed with our observations that forage generally remained 

 succulent longer during years that also had the highest forage 

 yield. 



Although both precipitation and temperature were 

 important, most variation in forb yield was explained by mean 

 temperature during May. Most variation in shrub yield was 

 explained by precipitation during the previous July-April 

 period (Chapter 3). When fawn survival was regressed against 



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