CALIFORNIA FISH AND GAME 261 



and gave birth July 16, 1930, to a male and a female fawn. She bred 

 again on December 21, 1930. 



''One female fawn that was born July 17, 1928, bred for the first 

 time on November 27, 1929, and gave birth to a single fawn on June 

 23, 1930. The other female that was also born on July 17, 1928, bred 

 for the first time on December 7, 1929, giving birth to two fawns on 

 July 5, 1930. This doe bred the following season on December 18, 

 1930." 



From the above data it will be seen that the actual gestation period 

 of Rocky Mountain mule deer in four known instances was 205, 207, 

 208 and 209 days, or approximately seven months, in marked contrast 

 to six months which is so often given for this species. 



Observations ' have shown that practically all of the deer in the 

 Yosemite region breed between December 10 and January 27, these 

 two dates representing the earliest and latest dates upon which actual 

 copulation has been observed. Checking up by actual observation the 

 following summer, I found that the first fawns (twins) were born at 

 noon on July 9, and that 90 per cent of the pregnant does had dropped 

 their fawns by July 30. 



When adult does are far advanced in pregnancy (see Fig. 98), they 

 are much more sedate and do not bound wildly about as they do at other 

 times of the year. This change in the demeanor of a pregnant doe was 

 strikingly illustrated by an experience that I had on May 15, 1925, at 

 Eagle Lake, Lassen County, California, when a large doe was noted 

 loping along an open stretch of timber which led down toward the lake. 

 She was very heavy with fawn and, although considerably alarmed, she 

 slid along easily, not bouncing about stiff-legged as does customarily 

 do under such circumstances when they are surprised in late summer 

 or fall. 



The fawning period of the mule deer is found to extend over 

 several weeks. This is doubtless due to the fact, which I have observed 

 many times, that all the does do not breed at the same time, and, since 

 the breeding season extends over almost two months, the fawning 

 period likewise varies considerably. Due to the fact that the mating 

 season varies slightly from year to year, according to the general cli- 

 matic variation of the season, we find that there is considerable varia- 

 tion both as regards the mating period and the subsequent fawning 

 period. In all of the various seasons that I have spent in Yosemite, I 

 have never seen other than an occasional spotted fawn before the first of 

 July, and in many instances individual does which were known to be 

 heavy with fawn have been watched critically for days at a time at 

 this period of the year. 



Thus on July 2, 1929, at 5.30 in the morning I was watching an 

 old mule deer doe in the meadow by the Ahwahnee Hotel in Yosemite. 

 She was a mature doe in good flesh and was in the full red summer coat, 

 I could tell by her anxious actions and by the way that she kept watch- 



6—12731 



