DECIDUOUS NATURE OF DEER ANTLERS 359 



was tested on a final group of 4 deer which were not castrated. These 

 were given injections of 5000 lU of chorionic gonadotropin (Antni- 

 trin-"S"; Parke, Davis and Company) according to the same sched- 

 ule as before. One animal died accidentallv after a month, but the 

 3 others exhibited no signs of shedding or growth during the course 

 of 4 months and the accumulated administration of 150,000 lU of 

 gonadotropin per deer. Unhappily, such negative results are not 

 necessarily meaningful, for the preparations were highly soluble 

 proteins which might possibly have been effective had they been 

 injected in higher doses at more frequent intervals. Nevertheless, 

 as Wislocki ( 1943 ) has pointed out, gonadotropin secretion in nor- 

 mal deer is minimal when shedding and initial antler growth occur. 

 Therefore, its role would appear to be that of stimulating testoster- 

 one secretion and spermatogenesis, as the breeding season ap- 

 proaches, rather than influencing antler shedding several months 

 earlier. 



The deciduous character of deer antlers cannot be considered in 

 its natural perspective except as a component phase in the annual 

 reproductive periodicity typical of most deer. Hence, the shedding of 

 antlers nearly always occurs sometime after rut and before the season 

 of birth. Thus, newborn animals are not jeopardized by the presence 

 of antler-bearing adults except in the case of reindeer and caribou 

 cows that may not drop their antlers until soon after calving. An- 

 other interesting exception to this generalization is represented by 

 the roe deer. Not only does this deer possess mature antlers from 

 early spring (some 2 months before the fawns are to be born) 

 through late fall, but it is unique in that its antlers normally develop 

 during the winter instead of the spring and summer as in other 

 species. Moreover, it mates in July and August but implantation of 

 the ova is delayed until December, approximately 5 months before 

 birth. Considering these various departures from the more common 

 sequence of events, it would be surprising if the roe deer did con- 

 form to the reproductive patterns typical for most other deer. 



More specifically, the shedding of antlers may be correlated with 

 reduced spermatogenesis and diminished testosterone secretion such 

 as occur after the rutting season (Wislocki, 1949; Stieve, 1950; 

 Frankenberger, 1954). Accordingly, castration brings about pre- 



