Ptarmigan
2 of the 6 encyclopedias on this shelf carry an entry for Ptarmigan. Both are reproduced below, so you can see where they agree and where they differ.
Aiton's Encyclopedia (1910)
tar'mi-gan, an Arctic grouse. There are several species differing in summer plumage, but all are white as snow in winter. The ptarmigans are smaller than the prairie hen . They are densely feathered to the nails of the toes. They nest from Labrador and Manitoba northward. They live in the barrens, eating seeds and wild fruits. The willow ptarmigan, while ranging for food, often crosses the international line in winter as far south as the center of Minnesota. The ptarmigan is an exceedingly hardy bird, taking refuge in an arctic snowdrift as readily as a seal in the water. The corresponding ptarmigan of Europe is a resident of the northern part of Norway, Lapland, and Siberia. A species is found in the high altitudes of the Rocky Mountains . They nest on the ground and have the habits of prairie chickens. See Grouse
Collier's New Encyclopedia (1921)
Lagopus mutus, a game bird found in the N. of Europe, especially in Norway and Sweden, and in the United States. In winter the plumage of the male is almost wholly white, with a small patch behind the eye; A B ROCK PTARMIGAN A. Summer Plumage B. Winter Plumage the shafts of the primaries and the bases of the exterior tail-feathers are black, and there is a patch of bare red skin around the eye. In the summer the black retains its position, but the white is mottled and barred with black and gray. The length of the adult male is rather more than 15 inches. Their call is a harsh croak.
What Has Changed in the Last Century
The natural history in both accounts still holds: three species of Lagopus turn snow-white in winter, are feathered to the toes, nest on the ground and range from the Arctic barrens down to the alpine zone of the Rockies. Two small corrections have come with time: Collier's Lagopus mutus is now written Lagopus muta (rock ptarmigan), and Britain's red grouse, once treated as its own species, is generally classed as a subspecies of the willow ptarmigan the 1910 account describes wandering into Minnesota. That willow ptarmigan became Alaska's state bird in 1955. The larger change is not in description but in fortune: the hardy bird that Aiton's said took refuge in a snowdrift "as readily as a seal in the water" is now a standard example of a cold-adapted species squeezed by warming, with rock ptarmigan in the Alps and Scotland and white-tailed ptarmigan in Colorado retreating upslope as suitable ground shrinks.
Written for this edition, 2026.