THE RED FOX (Vulpes kenaiensis) is widely distributed throughout Alaska and is an important fur resource. In Mount McKinley National Park it is numerous and prospering. Along the north boundary trappers take many, some of which probably have drifted out of the park.
There seem to be an unusual number of silver and cross foxes in the park. I knew of six different adult silver foxes and three pups of this color phase. Cross foxes were frequently seen; in places they appeared to be as numerous as the red ones. The percentage of the different color phases varies in different areas. North of Wonder Lake a trapper captured three or four silver foxes in the winter of 1940-41; on lower Savage River a trapper had taken 15 or 20 reds and no silvers; and a trapper farther east had three reds and four crosses. In 1940 at Sable Pass a pair of cross foxes with blackish faces and more black hairs in their coats than usual had a litter of three pupsone cross and two silvers; and in 1941, in the same den they had four pops two cross, one silver, and one red. In this general area there were some adult silver foxes too, so that it appears that here a strong strain of this color phase had been developed.
Some information on home range was gathered incidentally. A male fox, easily identified because of a missing lower canine tooth, was first seen on April 24, 1939, near the cabin on Igloo Creek. During the summer the fox was rarely seen, but in September and October he often came to the building and became rather tame. He learned to come to me when I whistled, and once followed me a mile from the cabin when coaxed with tidbits. In 1940 I lived elsewhere so had less opportunity to watch this fox, but he was seen twice, on June 21 and November 17. While I stopped a few days at Igloo Creek in February 1941, the fox appeared, looking for scraps.
During the summer of 1941 he was seen regularly in the same vicinity. This fox, then, lived in the neighborhood continuously for at least 2 years and 3 months. No information on the extent of his range was secured; when seen he was always within a few hundred yards of the cabin.
At Sable Pass a pair of unusually colored cross foxes used the same den in two successive years. The same foxes, apparently, were seen in the area in winter.
Near the cabin on Toklat River a cross fox lived for at least 3 or 4 years. The building was vacant most of the year but whenever occupied, summer or winter, the tame fox made its appearance for scraps. It was not fed regularly enough to restrict its movements.
An unusually beautiful silver fox lived on the east side of Sable Pass. I first saw him on April 23, 1939. He discovered me when I was only 7 yards away, looked at me with eyes which, in the bright sunlight, were only slits, then continued unhurriedly on his way. I was often close to him but this was one of the few times he ever deigned to look directly at me. Usually he went about his affairs as though I did not exist, even when I was near him. He was always seen in an area about 3 miles across, south of the draw where I suspected he was denning. In 1939 he was seen during the summer and again in late October shortly before I left the park. In the summer of 1940 I continued to see him at frequent intervals. In November he was seen on two successive days near the same spot. In the spring and summer of 1941 he was frequently seen. Twice he was carrying food, apparently to his den. This fox was known to occupy a definite range over a period of 2 years and 3 months. Since this fox lived some distance from any cabin and was never fed any scraps, he was existing in an entirely natural environment.
Although some foxes seem to live all year in a restricted home range, there may be, at times, general movements of foxes. A trapper told me that during a mouse epidemic on his trapping ground there seemed to be an influx of foxes from other areas. This was correlated with a scarcity of foxes reported by other trappers some distance away where mice were scarce. The increase noted may of course have been due to a good fox crop as a result of a large carry-over of breeders and an abundant food supply. Little was learned concerning the dispersal of the young each year. They probably wander about considerably and fill in unoccupied territories.
The proximity of some of the occupied dens suggests the size of the home ranges but of course there may be a deep overlap of territories. Two dens were 5 miles apart. Two others were 6 miles apart. About half way between the latter two I was sure there was a third den, which would place these dens about 3 miles apart. The ranges of these foxes overlapped to an unknown extent.
Dens were found in various situationsin the open and in the woods, on sunny knolls far up the slopes, and on the flats. Most of them were dug in sandy loam, but a few were located in hard clay. Generally they were found on south-facing knolls where the soil was somewhat loose. A typical den has from 6 or 7 to 19 or more entrances. In one instance there were 19 entrances over an area 10 yards across and 25 yards long.
Ten occupied dens were found without making a special search for them. In 1940 five were located along a 32-mile stretch of the highway. In this same stretch the approximate location of four other dens was known. This gives some indication of the abundance of the foxes in the park.
The parents at one of the dens, which I kept under observation, both participated in feeding the pups. There was no difficulty in supplying the required food, for uneaten remains of mice and ground squirrels were frequently seen about the den. Sometimes when there was a surplus, the food was cached by the foxes on the premises. In caching food, a shallow hole is dug with the paws, and the food is covered with dirt by making forward strokes with the nose.
The pups rested most of the day, usually inside the den, but not infrequently on a mound at one of the entrances. In the daytime the pups behaved as though they were tired and sleepy. Most activity was noted in the evening and in the early morning, which was perhaps the beginning and the ending of their nocturnal activity. At these times the pups played together vigorously.
On July 9 at 4 p. m. an adult brought a ground squirrel and dropped it near one of the entrances. After lying down a few moments the adult returned to the ground squirrel and dropped it in front of one of the pups. Two other pups suddenly appeared and there was a scramble for the squirrel; one of the pups dove into a hole with it. Later a pup was seen playing with a dead mouse. The parent lay down at one side of the den on a favorite spot. She licked one of the pups thoroughly with her tongue. Two other pups appeared and they all trailed after the mother as she moved about the den, playing among themselves when she sat on her haunches. She left them and hunted mice on a slope while they watched her intently from the den. This activity at the den was typical when a parent was with the pups.
I do not know how long the young remained at the den. In one case the pups were still at a den on September 21. On September 28 a black pup was seen alone half a mile from this den so it appeared the pups at this time were wandering widely. During the summer the foxes sometimes changed dens; in two instances changes were made when the foxes were undisturbed so far as I knew. There sometimes are several vacant dens near an occupied one.
The same dens are sometimes used in successive years just as is the case among the wolves.
Injuries and Disease
Only two crippled foxes were seen. One was not using a front leg, the other, a silver fox, was limping badly on a hind leg.
No foxes definitely known to be sick were noted, but a fox seen on June 14, 1940, behaved as though it might have been ailing. It would not move from a clump of spruces where it was lying until I crawled in after it and then it ran out and stopped only 20 yards away. When I walked toward it, it returned to its bed. I approached it again and it moved over to another clump and lay down. It may not have been sick but only behaving toward me as it would toward a caribou that disturbed its rest. Possibly it had not seen a human being before.
In the spring of 1922 a trader told O. J. Murie that foxes had been unusually abundant in the lower Kuskokwim country in 1907, and that they had died of a disease which was thought to be rabies, since several dogs bitten by the foxes had died.
In early June of 1939 I found a dead female fox at Stony Creek which had not been touched by anything. It was an old fox with well-worn teeth so it may have died of old age. In the stomach was a ground squirrel.