Fauna Series No. 3

Fauna of the National Parks — No. 3 Birds and Mammals of Mount McKinley National Park

Mammals

DESCRIPTIONS OF MAMMAL SPECIES

MACKENZIE VARYING HARE
Lepus americanus macfarlani [MERRIAM]

GENERAL APPEARANCE.—In size and general appearance varying hares are about halfway between a cottontail and the common jack rabbit. The ears are longer than those of a cottontail but not as long or as large as those of a jack rabbit. The hind feet of the varying hare are so large that the animal is often called snowshoe rabbit. In winter the pelage of this hare is pure white, but in summer it changes to brown. Length, 18 inches; tail 1.5 inches; hind foot, 5 inches; ear from crown, 3.5 inches.

IDENTIFICATION.—In June when visitors begin to arrive at McKinley Park these hares are in their brown summer coats although small patches of white, remnants of their winter coats, may still be visible here and there even as late as midsummer (fig. 63). The large elongated tracks which they leave in the snow are characteristic of these hares, as are also the flattened pill-like droppings.

DISTRIBUTION.—Mackenzie varying hares are found from Cook Inlet and the base of the Alaska Peninsula east to western Mackenzie, northern British Columbia, and northwestern Alberta. In Mount McKinley National Park during "rabbit years" these mammals are found throughout the timbered portions of the park as well as in willow thickets above and below timber line.

HABITS.—When we arrived at our Savage River camp on May 19, 1926, we found varying hares to be abundant in the black spruce woods nearby. Rangers living in the park told us that the "peak" abundance of snowshoe rabbits had been reached in 1925 and that they had been increasingly abundant for three seasons. The period of maximum abundance of the varying hare usually occurs every 10 or 11 years.

During the winter of 1925 acres of willow thickets had been stripped of bark as high up as the hares could reach. On May 22, 1926, I found and photographed the top of a black spruce tree which had been blown down by severe winter winds. It had then been stripped of all the green needles and much of the bark by the hungry rabbits (fig. 8).

Residents told us that the hares which had been pure white all winter first began to acquire their brown summer pelage about the 20th of April. On May 26, 1926, I collected an adult male hare. The sides and both the front and hind feet of the specimen were still white. However, by this date most of the hares were in their brown summer coats, although their feet and the outer margins of their ears were still white (fig. 63). On June 10 I shot a "pinto" hare. Its brown pelage still showed several white patches which were about 1 by 1-1/2 inches in size. This hare contained four embryos each three-fourths of an inch long. On the same day another female hare was shot. It contained three well developed foeti each 4 inches long and almost ready for birth.

Figure 63.—A Mackenzie varying hare in the short-haired brown summer coat, but with patches of the white winter coat still adhering to sides and flanks. The white willow limbs in the background had been stripped of their bark by hungry hares the previous winter.
Photograph taken June 3, 1996, Savage River. M. V. Z. No. 5008.

A careful search through the rabbit areas was made on July 25, 1926, and we were surprised to find that the hares were not as numerous as they had been 2 months previous. Although we searched carefully we were unable to find a single living young hare. In fact we saw only three young hares all summer. The hares had bred but apparently reproduction had been faulty. Also, some of the old hares were dying of "rabbit" disease, possibly Tularemia.

Varying hares have many enemies to elude. Among mammals the chief enemies of the Mackenzie varying hares are Canada lynx and Kenai red foxes. Perhaps as many, or more, hares are captured by the Kenai red fox than are captured by any other of the Mackenzie varying hare's natural enemies. Among the birds, the Saint Michael horned owls and the American hawk owls are their worst enemies.

When I visited Mount McKinley National Park in 1932, I found varying hares to be at their periodic minimum. In fact, although I looked for them in suitable localities I did not succeed in finding a single one during the entire summer and was told that only one had been seen in the region throughout all of the previous winter. The last peak of abundance was in 1925.

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Last Modified: Thurs, Oct 4 2001 10:00:00 pm PDT
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