THE GAZELLES AND THEIR ALLIES 585 
the big gazelles were always switching their tails, almost 
precisely like the Tommies and not in the manner of their 
own kinsmen. This may have been an error of observation 
on our part, induced by the fact that on the Northern Guaso 
Nyiro there were no Tommies with which to make compari¬ 
sons. We wish other observers would look into the matter. 
The lives of these big gazelles were led under the same 
conditions as those under which the other plains game 
with which they associated—wildebeest, hartebeest, topi, 
zebra, Tommies—led their lives, and their habits were 
essentially the same. The bucks now and then fought 
fiercely for the mastery of the herds. There was no fixed 
mating season, as far as we could see; at any rate, we found 
fawns of all ages. The mother left the herd for a few days 
at the time of the fawn’s birth, but soon rejoined it, the 
little fawn being able to run with its elders at an early age. 
The herd would feed for a few hours and then rest for a 
few hours, watering once or twice a day. We could not 
find that these hours were definitely fixed. Usually the 
herd rested during the heat of the day, but several times 
we found herds feeding at high noon, and once we found 
one at a water-hole at that hour. We also, at one water- 
hole, found that the gazelles as well as the hartebeests vis¬ 
ited it at night. We saw them grazing very early in the 
morning and very late in the evening. They differed 
widely and inexplicably in wariness, like so many other 
kinds of game. As a rule, they were not as wary as wilde¬ 
beest and were much more wary than Tommies; but one 
herd would flee when we were half a mile off and another, for 
no reason that we could see, would let us ride by them within 
a couple of hundred yards. In the morning we might find 
