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Fauna Series No. 4

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Cover

Contents

Foreword

Introduction

Population and Mortality

Habits

Food

Elk

Deer

Antelope

Bighorn

Other Larger Mammals

Small Mammals

Birds

Misc. Diet

Conclusions

Bibliography


Fauna of the National Parks — No. 4
Ecology of the Coyote in the Yellowstone 		National Park Service Arrowhead


CHAPTER V:
ELK IN RELATION TO COYOTES

elk
Figure 13— A calf elk that died at birth but was not yet deserted by the mother.
It forms potential carrion for coyotes.
Base of Hellroaring Slopes, May 24, 1938.

CALF SURVIVAL, 1937

CLASSIFIED counts were made of elk whenever an entire band could be counted in order to get some idea of the calf increase in proportion to the cows and yearlings. The figures are not extensive but represent a fair sample. The percentage increase of calves in various bands is uniform considering the great chance there is for variation. My calf ratio is higher than that obtained by Rush (1932) between 1928 and 1931, from counts during the months of January, February, March, and April. His figure, converted so as to be comparable, is 25 percent and mine is 41 percent. The lower percentage of calves recorded by Rush may in part be due to the fact that his counts were made during the winter period when a relatively higher mortality occurs among calves. Summer counts made by O. J. Murie (1935) in Teton National Forest just south of Yellowstone National Park resulted in 1,192 cows and 458 calves, or a calf increase of 38 percent.

Elk Calf Survival, 1937

1937LocationCowsCalves BullsCalf-cow
ratio

June 1
June 13
June 28
July 12



Sept. 27







    Do.

Nov. 4
Nov. 6
Nov. 7
Nov. 11


Nov. 14

Nov. 15
Nov. 20
Turkey Pen
Trumpeter Lake
Slough Creek
do
Hayden Valley
    do
    do
Pelican Valley
    do
    do
    do
    do
    do
    do
    do
Hayden Valley
    do
Soda Butte
Horseshoe
Swan Flats
Blacktail
    do
    do
Geode Creek
    do
Mammoth
Blacktail
    do
    do

     Total
8
50
97
140
38
40
103
4
7
12
16
6
1
9
9
6
4
16
34
23
64
7
3
117
16
6
53
7
35
931
8
25
22
69
14
15
48
3
2
7
7
1
0
1
3
2
2
6
23
8
26
5
1
40
6
4
21
3
13
385
...
...
...
...
...
...
...
1
1
1
1
1
1
1
1
1
1
1
1
...
...
...
...
3
1
...
6
...
...
22 		Percent
100
50
22
49
36
37
46
75
28
58
43
16
0
11
33
33
50
37
67
34
40
70
33
34
37
66
39
42
37
41

THE high survival of calves in 1937 indicates that coyotes were not getting many. No good calf counts were made in 1938 but I suspect the crop was lower than in the previous year because of the hard winter of 1937—38, which resulted in the cows becoming abnormally thin and weak. Their condition was poor during the last months of the gestation period and during calving time.

elk
Figure 14— A very young calf elk shows remarkable faith in hiding and allows itself to be handled.
Soon calves become less tolerant and run away when approached too closely.
Tower Falls, May 29, 1938.

STATUS OF ELK

The elk population in Yellowstone Park is unquestionably too large, resulting in a severely overbrowsed winter range. The depleted range is harmful to the elk but even more harmful to the deer, antelope, and bighorn over whose ranges the elk wander and with whom they compete directly for food. The elk herd could safely suffer a loss of two-thirds of the present number, with benefit to the other ungulates, the ranges in general, and to the elk themselves. In an effort to improve the situation a program of elk reduction was inaugurated by the National Park Service in the winter of 1934—35.

All available data indicate that the coyote is a minor factor in the status of elk. Although the latter on the big game winter range on the north side of the park make up the bulk of the winter food supply of the coyote, it is in the form of carrion and little if any predation on elk exists at this season. During the calving period a few youngsters may be eliminated by the coyote but the data indicate that the calves eaten probably are largely carrion. Since there are now too many elk on the winter range occasional coyote predation on the calves would not be harmful to the welfare of the elk population.

elk
Figure 15— Elk cow slowly enticing calf less than 24 hours old away from aspen grove in which it was born.
Junction Butte, May 25, 1938.




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