BIRTH OF YOUNG. 19 
coarse marsh grass, evidently the plants which had grown in autumn 
after hay harvest. This grass had been kept green and succulent 
by its covering of ice and snow. In early May the icy flooring which 
had remained solid beneath the tangled grassy covering no longer 
held up the animals, and they all left about May 10. For some time 
longer upward of 100 remained on the East Gros Ventre Butte, 
several hundred feet higher than the valley level. Here they lived 
on the grasses and herbaceous plants which were fast springing up. 
These elk remained here until about May 25, and then part or all of 
them crossed westward and joined others on the larger West Gros 
Ventre Butte, which afforded them more protection. Upward of 
100 were seen there as late as May 31, and a few remained all summer. 
Some of the older bulls dropped their antlers about March 25, 
but the shedding continued for several weeks. Among a herd seen 
May 4 were a number of bulls still bearing horns, but by May 15 
even the younger bulls had all dropped them. As the shedding of 
antlers is dependent on the general condition of the animal, the proc- 
ess was delayed by the severe winter and late spring. In an earlier 
spring following a normal winter the new horns are already well 
grown in May, but in 1911 that mouth found most of the bulls with 
their horns scarcely started, and in mid-August many were still in 
the velvet. 
BIRTH OF YOUXG. 
About 75 per cent of elk cows over 2 years old bear young. The 
majority of calves are born between the 25th of May and the middle 
of June. Xearly all the testimony obtained on the subject is to the 
effect that only one calf is born at a time. A few thought that twins 
sometimes occur, but it seems probable that this opinion arose from 
the fact that a cow elk is frequently followed by two calves during 
the summer, the extra one being the deserted or orphaned offspring 
of another cow. Many of the hunters had examined large numbers 
of female elk with calf, and none of these ever found more than one 
fetus. The proportion of the sexes at birth is nearly even. Large 
numbers of the cows have their young in the hills in the vicinity of 
Jackson Hole, but probably the majority of the animals which 
come from north of Buffalo Fork return there before dropping their 
young. This varies according to the season, an early spring allow- 
ing a greater proportion to move northward before calving. The 
young are usually born in a thicket, very often among aspens, and 
are carefully concealed by the mothers when they have occasion to 
leave them. The calves are said to begin to graze at the age of 4 to 
6 weeks, and many are weaned in September. In some cases, how- 
ever, weaning does not occur until October, November, or even 
later. 
