Caribou.
Each spring the caribou appear in faded, dun coats, their color pattern gone, the long hair worn and frayed. Winter hardships are behind and the sprouting, nutritious, vitamin-packed green forage is available—nature’s restorative. On the hummocks the caribou are already finding the new growth of sedge hidden by the old, leached, brown blades. As the winter coat is shed, and the new black pelage shows in patches, the animals have a moth-eaten look.
In May and early June, the caribou that have wintered along the north boundary of the park and northward to Lake Minchumina, move into the park, continue eastward to the Teklanika and Sanctuary rivers, and cross to the south side of the Alaska Range over the glaciers at the heads of these rivers. At this time the bands are small, numbering from a few individuals to one or two hundred. After feeding on the south side of the range for 2 or 3 weeks, the caribou return en masse, usually in late June or early July, but in 1960 about the middle of June. Herds numbering one or two thousand are not unusual, and I have seen an assemblage of four or five thousand. The herds cross Sable Pass and travel parallel with the road to Muldrow Glacier. From there they may strike northward or continue on westward. In August and September at least a few caribou may be found especially in the Wonder Lake area.
Caribou are inordinately fond of lichens which they eagerly feed upon at all seasons. In summer they take advantage of the variety of foods available and feed extensively on grasses, many herbaceous species, willows, and lichens. Lichens are much sought in fall and winter, and in these seasons grasses and sedges continue to be major foods.
Caribou are plagued by warble flies and nostril flies throughout the summer. These beelike insects cause the caribou great annoyance. The warble fly lays eggs on the hair of the legs and underparts of the body. The eggs soon hatch, the larvae penetrate the hide, and move to the back region where they emerge as swollen larvae in the spring. The nostril flies deposit living larvae in the nostrils. The larvae become lodged back in the throat in a mass and the following spring are coughed out; they pupate on the ground, and soon emerge as terrorizing flies. A caribou may dash away in panic to escape a fly, then stop in a wet sedgy depression and hold its nose close to the ground. Thus it may stand for long periods if not attacked. On sunny days when the flies are very active, the movement of the herds is drastically influenced. The large herds may seek a high, breezy ridge, or a snowfield, to minimize the attack. Commonly, one or two thousand on such days assemble in a compact group on a broad gravel bar where they may stand all day. Should clouds cover the sun, the herd disperses to feed, but again converges if the sun reappears.
A caribou bull.
By midsummer the old hair has been shed and the caribou are in a short blackish coat that continues to grow. Not until September is this new pelage fully developed. By then it has become a rich chocolate brown, trimmed with white. The pattern is most striking in the old bulls. A silvery cape covers the neck and part of the shoulders and forms a mane on the throat. A white line extends back along the sides of the body, and the belly is white. The blunt nose is tipped with white and an oval white patch surrounds the tail. A white patch shows the location of the upper gland on the hind legs. White anklets border each shiny black hoof. The pattern is similar, but much more subdued in the cows and younger bulls.
The magnificent antlers of the old bulls have hardened by late August. The velvet covering them during their growth is now rubbed off with a vigor suggesting the oncoming rut. At first the white antlers are often stained pinkish by the blood in the velvet. Continued rubbing on the brush removes the pinkish color and the antlers develop to a rich brown.