HABITATS of birds and mammals of Mount McKinley National Park may be segregated into two general groups according to the presence of moisture and general presence or lack of vegetation. Many square miles of glaciers and frost-riven rocks were fotsnd along the crest of the Alaska Range. Although glaciers contain a high percentage of water, this moisture remains frozen and consequently is not available for food production for either plant or animal life. It follows, therefore, that since Mount McKinley is blanketed deeply throughout the year with many feet of snow and ice (fig. 2) there is little animal life on the mountain proper. As a matter of fact, no bird or mammal life was found above 7,000 feet elevation save for an occasional transient eagle or gyrfalcon observed soaring over the rocky summits.
In the first group are the habitats characterized by little or no vegetation. These habitats are as follows:
1. Mountain summits, 7,000 to 20,300 feet altitude, covered with snow and ice throughout the yeardevoid of animal life save for some soaring gyrfalcon or eagle.
2. Rocky ridges, 4,500 to 7,000 feet altitude, snow-covered for 9 months of the year hut bare in summer time, except for creeping Arctic willows and similar vegetationthe characteristic home of the Kenai white-tailed ptarmigan, American pipit, European wheatear, and Hepburn's rosy finch.
3. Talus slopes and rocky cliffs (fig. 3), 3,000 to 4,500 feet altitudethe characteristic home of the collatered pika, Northern hoary marmot, Dall sheep, and surfbird.
4. River gravel bars (fig. 4), 2,000 to 3,500 feet altitudethe breeding home of the wandering tattler, short-billed gull, and semipalmated plover.
In the second group are the habitats characterized by more vegetation. These habitats are as follows:
1. The shallow lake and pond (fig. 5). 2,000 to 4,000 feet altitudethe breeding ground of old-squaw duck, horned grebe, lesser scaup duck, and herring gull.
2. The wet "nigger-head" tundra and marsh, 2,000 to 4,000 feet altitudethe breeding ground of Hudsonian curlew and long-tailed jaeger.
3. The willow and alder thicket, 2,500 to 4,500 feet altitudethe breeding ground of the American magpie and Alaska ptarmigan.
4. The spruce woods (fig. 6), 1,000 to 3,000 feet altitudethe characteristic home of the Northern red squirrel, Alaska porcupine, Mackenzie varying hare, Alaska jay, Alaska chickadee, and Kennicott's willow warbler.
5. The Alpine meadow, 3,000 to 4,500 feet altitude, with its growth of grass and heatherbreeding ground of the meadow mouse.
6. The dry tundra, 3,000 to 4,500 feet altitudethe breeding ground of Pacific golden plover, pallid horned lark, and Alaska longspur.
While the foregoing habitats are readily distinguishable, the elevations at which they occur vary considerably and the visitor to the park should not be surprised if a certain habitat is found above or below the elevations given here.