Age and Condition of Coyote-killed Deer 



During winters, 1975-1986, 149 deer carcasses, including 

 radio-collared deer, were examined and classified as coyote- 

 killed deer. These included 118 mule deer and 31 white-tailed 

 deer from the adjacent river bottoms. Very little remained of 

 most carcasses, and 76 (58 mule deer and 18 white-tailed deer) 

 were of unknown sex and age. Because of the small size of 

 fawns and their relatively higher rate of disappearance over 

 winter, it is likely that many of the unknown sex and age 

 carcasses were fawns. Of the remainder, 34 were adult mule 

 deer, 26 were fawn mule deer, 10 were adult white-tailed deer, 

 and 3 were fawn white-tailed deer. For adults classified to 

 sex, 20 mule deer and 8 white-tailed deer were adult females 

 and 2 mule deer were adult males. Of the 30 adults of both 

 species and sexes aged to specific age, 9 (30%) were 

 yearlings, 15 (50%) were between 2 and 8 years of age, and 6 

 (20%) were 8 years old or older. This small sample did not 

 indicate that coyotes selectively killed adult deer in 

 different age categories than occurred over long periods in 

 hunter-killed and captured samples of female deer (Table 4.4). 



Estimates of FMF content for coyote-killed deer ranged 

 from 70-96% for 14 deer, 32-62% for 10 deer, and 7-17% for 8 

 deer examined over 10 years. Deer in relatively poorer 

 condition did not prevail in this sample. 



Fat content of femur marrow is not enough, by itself, to 

 determine deer condition (Mech and Delgiudice 1985). For 

 example, deer with FMF content in the range of 70-96% (white 

 and firm) could either be in excellent condition or on the 

 verge of protein catabolism and starting to utilize critical 

 body fat reserves. In northern environments, fat reserves and 

 body condition of deer usually decline over winter (Anderson 

 et al . 1974, Mautz 1978), even in areas where deer are on a 

 relatively high nutritional plane during the period (Dusek et 

 al. 1989). 



Timing is also important; deer with FMF content of 40% in 

 January are in worse condition than those with FMF content of 

 40% in March. As indicated earlier, most females with a FMF 

 content below 20% during March and April 1985 apparently 

 survived winter and recovered to recruit fawns during 1986 and 

 1987. Of 32 marrow samples from coyote-killed deer, only 

 about 7 were considered in such poor condition at the time of 

 death that over-winter survival was unlikely. We do not mean 

 to imply that the remainder of deer killed by coyotes were in 

 excellent or good condition, only that they fell within the 

 "normal" range of conditions for deer at the time of the year 

 they died. The FMF content of 2 fawns and 3 adults killed by 

 coyotes during February and March 1977-80 was considered to be 

 excellent and above "normal" for that time of year. 



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