CALIFORNIA FISH AND GAME 253 



On September 16, 1933, I counted the deer in this same meadow and 

 found : 



5 adult bucks (three 3-point and two 4-point). 

 8 adult does. 

 4 young does. 



3 spotted fawns. 



On December 18, 1929, I counted the deer in this meadow and 

 found : 



2 adult bucks. 



4 adult does. 

 4 fawns. 



At first sight the relative number of mature bucks to does and 

 fawns may seem comparatively unimportant. However, a detailed 

 study of mule deer in various parts of California indicates : 



1. The hunting season of mule deer comes before the mating season. 



2. Vigorous, mature bucks bear the biggest and best antlers. 



3. Such bucks carry the "heads" that make the best trophies, and 

 thus the individuals that nature has selected to breed and to perpetuate 

 the race are the very ones especially sought for and killed by the 

 licensed hunters of the State. 



4. Where the number of such vigorous breeding bucks is unduly 

 decreased, mating is deferred, or accomplished by inferior bucks, 

 resulting in many late or weakling fawns being born. 



5. Such late or weakling fawns are often not properly weaned, 

 owing to lack of suitable green, succulent forage in late summer. As 

 a result, these fawns continue to be a serious drain on their mothers, 

 so that both mother and fawn enter the winter in a backward, weak- 

 ened condition, falling easy prey to predators, disease, cold, and star- 

 vation. 



YOUNG VERSUS MATURE BUCKS AS BREEDERS 



At mating time, in a polygamous species such as the mule deer, 

 victories go principally to males of full physical strength and vigor. 

 The tendency is for the weaker bucks to be driven off by the stronger 

 ones, and a system of selective breeding which tends to exclude both 

 immature and old decadent males from breeding results. It is believed 

 that this is nature 's way of insuring the survival of the fittest, thereby 

 keeping up the vitality and vigor of the race. 



It would appear, from my investigations, that this critical breed- 

 ing period in a mule deer normally extends over a relatively short 

 span, perhaps for not more than three or four years of his life when 

 he is in his prime and physically at his best. 



It has been pointed out that physical strength and sexual potency 

 may not decline uniformly in an aging animal. It has been found that 

 in elk and in other members of the deer family, a well-established bull 

 or buck may sometimes hold his harem against all rivals after there 

 has been a decided lowering in his fertility. However, the leadership 

 of the "herd" buck is challenged constantly and he is forced to fight 



