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JOURNAL OF MAMMALOGY 
case of the last animal, the disease is particularly virulent, and few, 
if any, recover from an infection. 
Internal parasites are of several kinds that infest domestic sheep, 
goats, and cattle — tape worms, stomach worms, whip worms, and 
hair worms. There is also a tape worm found in foxes, wolves, and 
coyotes, which in the embryo stage is found in our antelope. 
External parasites that we must guard against are the wood tick and 
the scab mite; both of which are dangerous because of debilitating effect 
on the victim. 
For approximately three months, from about the first of November, 
prong-horns gather together in large bands for mutual protection. 
This period corresponds with the growing season of the bucks’ horns, 
when they are least able to defend themselves. It is interesting to 
observe that during these three months, the bands are led by the does 
although there may be several full-grown bucks present. More than 
once I have seen a band, when climbing a low elevation, stop before it 
reached the crest, permitting the leading doe to run up and look over 
to examine the country ahead for some minutes before she returned to 
lead the band up and over. Prong-horns are usually watchful enough 
to prevent the close approach of an enemy, for it is their rule to 
occupy good lookout positions, and they frequently have sentinels 
posted whose only duty is to watch while the rest feed. 
Coyotes, especially when banded together in packs, are the most 
dangerous of the antelope’s enemies. Even so, I do not believe they 
catch many of the healthy adults, although a few of the old and diseased 
animals fall victims. Undoubtedly the coyotes cause additional 
damage by worrying them, and keeping the nervous animals stirred 
up and excited. The gray, or timber, wolves kill a few antelopes, 
although as a rule they confine their attacks to larger and slower animals. 
Owing to the peculiar rough and broken character of our winter range, 
affording good lurking places, the mountain lions manage to kill a few 
under exceptionally favorable circumstances. I doubt if a bear can 
catch a prong-horn unless he finds a very young kid hiding. Buffaloes 
occasionally kill very small kids, but as a rule, even the youngest are 
speedy enough to escape. The only birds I can think of as possibly 
dangerous, are the great golden eagles; there I should say the danger 
was small because other game, during the extreme youth of the kids, 
would be easier to get. 
It is extremely difficult to determine how long antelopes live. They 
reach maturity at five, and, as a rule, live from three to five years 
