Hauling field gear up Gothic Mountain…
The Southern White-tailed Ptarmigan, Lagopus leucums altipetens, was observed in Colorado by the writer in the years 1941 to 1947.Observations were made on various occasions in the Sawatch Range of Gunnison County, the Ten Mile and Williams ranges of Eagle and Pitkin counties, the vicinity of Berthoud Pass, and in Rocky Mountion National Park.Ptarmigan were seen in all seasons of the year, but this report relates to the winter season when observation is simplified by readable signs of activity in the snow.In the winter in this region, deep snow limits the available food to a few species of plants.Most abundant are the various willows and alpine fir, some alder, little bog birch, Englemann spruce and limber pine.On wind-swept rock fields lichens, mosses and withered alpine plants are available.Here, too, ptarmigan find grit in the little basins of weathered rock between boulders.It was noted that the largest flocks of birds were found in high alpine basins where willows were abundant.Ptarmigan appeared in flocks of five to thirty in these basins.Occasionally single birds were found in alpine conifer types such as dwarfed alpine fir, sometimes called "shinnery" or "shintangle," and in stunted limber pine stands at timber line.Birds were sometimes seen on high-angled rock slopes which are generally bare of snow.When flushed from this habitat, ptarmigan would usually dive off in fast flight for the snow basins lying below.Sometimes, when the observer was climbing, birds would be flushed at the tip of an approaching ski from hiding places under the snow.The birds would burst from concealment in a puff of powder snow and hurtle off 30 or 40 yards to drop duck-like into the snow and hiding.Flights of half a mile have been witnessed.On one occasion in Rocky Mountain National Park, a flock of about 25 birds flew up-mountain directly across a wind of gale proportion.The flight power of ptarmigan seems to be as strong as that of some of the other members of its family, although at times their hesitancy to fly might belie this ability.After a few periods of observation the writer noted considerable browsing of ptarmigan by tracking the birds.Signs in the snow made interpretation rather easy.Ptarmigan not only take the buds of willow but also nip off whole twigs as large as 1.5 mm.long and 2 mm. in diameter.The occurrence of twig stubs with shreds of bark torn down the stem suggested a plot method of food habits study similar to that used for investigations of big-game food habits.Several trial plots of one square foot each were marked at random and the availability of vegetation rated.Then a count of the browsed twigs was made as an index of use.One plot with an availability of approximately 150 twigs was browsed 40 times, or 26.6 per cent.On this particular plot, only willow occurred.This method was used only as a trial and is mentioned as an aid to further study.The changing snow level creates a varying availability by alternately covering and exposing different levels of vegetation; this factor would require consideration in such a study.The method used in this report was mainly the analysis of droppings.Over 500 droppings were collected off the surface of the snow and from roosting holes in the snow.Usually six to ten droppings would be found in a roosting hole.Droppings were easily collected off the snow surface among the willows which the birds seem to favor.Of the collections made, 145 droppings were weighed and measured separately, the remainder being weighed and analyzed in bulk.All samples were first oven dried.The Nov.
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