in the coyote population, apparently in response to an 

 abundance of food, was also documented during 1984 (Fig. 

 5.12), following peaks in microtine and jackrabbit populations 

 in 1982-1983 and high overwinter mortality of deer during 

 1983-84. Although coyote numbers declined during 1974-1977, 

 they apparently remained sufficiently abundant during 1973- 

 1975 to put extra predation pressure on deer despite the minor 

 peak in microtines during 1974-75. 



Our interpretation of the apparent unusually heavy impact 

 of coyote predation on the low deer populations of 1972-1977 

 may be similar to the relationship described by Gasaway et al . 

 (1983) for wolf and caribou (Rangifer tardandus) populations 

 in Alaska. That is, the effects of predation may be inversely 

 density dependent and, when combined with harvests (predation 

 by humans), may maintain deer populations at low levels unless 

 or until environmental conditions change significantly. 

 Similar observations were reported for wildebeest and their 

 predators in Kruger Park, South Africa (Smuts 1978, Walker and 

 Noy-Meir 1979) . 



Collectively, trends in fawn survival relative to 

 vegetation conditions, coyote and alternate prey populations, 

 and winter severity for the period 1960-1975 indicate similar 

 interactions of all factors on fawn mortality as previously 

 described for the period of intensive studies (1976-1987, 

 Chapter 5). Thus, interpretation of the role and importance 

 of any single environmental factor on fawn mortality and 

 recruitment on our study area and similar environments cannot 

 be determined independently of all others. 



Although relative body condition of deer may influence 

 coyote predation rates on fawns, not all deer killed by 

 coyotes were in noticeably poor condition, and even many of 

 those killed when in relatively poor condition might have 

 survived in the absence of predation. Several factors other 

 than body condition and alternate prey population levels were 

 involved in coyote predation on deer during winter. For 

 example, both deer behavior, based on age and experience, and 

 local environmental and site conditions played a role. 



Observations of coyotes attempting to prey on deer as 

 well as observations of deer behavior during drive-trapping 

 indicated that, under pressure, fawns are the most likely of 

 all deer to either break away from the group or to stop and 

 stand in confusion. This behavior was also noted by Griffith 

 (1988). Thus, although fawns are generally in somewhat poorer 

 condition than most other deer during any year (Runge and 

 Wobeser 1975, Dusek 1987), it is often their behavior when 

 attacked that makes them vulnerable to predation. Deer in 

 relatively poor condition may tire sooner and stop or break 

 away from a group, but fawns exhibited this behavior even 



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