4 BULLETIN 1346, U. S. DEPARTMENT OF AGRICULTURE 



nal numbers at not less than thirty to forty millions, and possibly 

 more. 



George Bird Grinnell informed the writer that he has often talked 

 about the abundance of antelope with men familiar with the western 

 plains 50 years or more ago and has never met a man of experience 

 who did not agree with him that during the middle of the last cen- 

 tury antelope were far more abundant than buffalo. During the 

 summer of 1879 Doctor Grinnell found them extremely abundant 

 in North Park, Colo., where he saw trails made by them in travel 

 from one locality to another worn in the hard soil to a depth of from 

 8 to 10 inches, like the trails made by buffalo herds going to and 

 from water or during their movements from one district to another. 



As against the many millions of pronghorns once inhabiting this 

 continent a recent census, taken through the Biological Survey and 

 detailed elsewhere, shows approximately 30,000 survivors. (See 

 Table 1, p. 3.) 



CHARACTERISTICS OF THE AMERICAN ANTELOPE 



Horns. — The pronghorn is the only antelope in the world with 

 branched or pronged horns, and has the unique characteristic among 

 all hollow-horned ruminants of shedding the outer covering of the 

 horns annually. This' takes place soon after the rut in November 

 and December in the Yellowstone National Park in northern Wyo- 

 ming, and elsewhere in the range of the species this time probably 

 varies somewhat with latitude. 



When the time for shedding arrives the horny sheath gradually 

 loosens and becomes detached from the skin around the base and, 

 following this, from the bony core within. Later the horn falls off, 

 leaving the bony core covered with a blackish skin more or less 

 overgrown with long, coarse hairs, which afterward are gradually 

 lost. A new horny nucleus develops on the tip of the bony core, 

 the horny growth then extending slowly downward until it reaches 

 the base. Gradually thickening and hardening, the horny material 

 grows at the tip until the new horn attains its full development.; 

 The horns continue to grow as the animal increases in age until 

 the full size is reached. 



Both sexes have horns, those on the does being smaller and slen- 

 derer than on the bucks. 



Bump patch. — Another characteristic of these interesting animals 

 is a conspicuous rump patch composed of white hairs which are 

 longer than those elsewhere on the animal's back. Through develop- 

 ments in the skin muscles the pronghorn at times of excitement has 

 the power to erect these white hairs until they stand out stiffly over 

 the rump, forming a great dazzlingly white rosette, like a giant 

 chrysanthemum, which, when the animal is dashing away across 

 the plains in the bright sunlight, is extraordinarily conspicuous. 

 The writer has many times discovered bands of antelope running 

 on the open plains where but for these heliographic patches they 

 would have been beyond ordinary eyesight. These long rump hairs 

 lie like other hairs on the skin and give little indication of their 

 strikingly conspicuous appearance until the animal suddenly throws 

 them up into action. The antelope fawns at a very early age 



