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The midget faded rattlesnake (Crotalus viridis concolor) has long been considered a subspecies of the western rattlesnake (C. viridis). This document will follow this convention, although there is some discussion of taxonomic revision at the species level that would categorize the midget faded rattlesnake as C. oreganos concolor (Crother et al. 2003). Midget faded rattlesnakes are a pale brownish gray, cream, or straw color. Blotches on the body are faded, subrectangular or sub-elliptical. As with most rattlesnakes, the most distinguishing feature is the rattle. Midget faded rattlesnakes are pit vipers, with the typical heat-sensing pits on each side of the head, between the eyes and mouth, used for detecting prey....
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The dwarf shrew (Sorex nanus) is one of the smallest mammals in the world, and inhabits a variety of habitats in western North America. Very little is known about this shrew, and relatively few specimens have been collected. Like most members of Soricidae, the dwarf shrew has a long and pointed nose, small eyes and ears, and a small body. It is difficult to distinguish from other shrews and generally has to be identified by dental characteristics. The dwarf shrew occurs primarily in mountainous areas, apparently preferring rock outcrops and talus slopes in alpine, subalpine, and montane settings. However, it has been occasionally found in lower and more arid environments such as shortgrass prairie, shrub-steppe,...
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The bald eagle (Haliaeetus leucocephalus) is the second largest North American bird of prey, with an average wingspan of 7 feet. On 20 June 1782 it was chosen as the emblem of the United States of America because of its long life, great strength, and majestic appearance. This selection had its detractors, most notably Benjamin Franklin who expounded on the bald eagle’s “bad moral character.” The bald eagle's scientific name signifies a sea (halo) eagle (aeetos) with a white (leukos) head (cephalus). In adult birds, the distinctive white head and white tail contrast starkly with the dark brown body and wings. When Europeans first arrived on the North American continent there were an estimated one- quarter to one-half...
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Weighing 10 - 15 kg and with a wingspan of 2.4m when fully grown, the trumpeter swan (Cygnus buccinator) is the world's largest waterfowl. Trumpeter swans are similar in appearance to other white swans, but their foreheads slope evenly to an all black bill. The more common and smaller tundra, or whistling, swan (C. columbianus) is smaller with a more curved upper bill, and usually has a yellow spot in front of its eye. The trumpeter swan is a long-lived, social species, conspicuous by its large size, all-white plumage, and trumpet-like call. Although once abundant and widespread in North America, populations were greatly reduced during the European settlement era when the species was prized for its skin and feathers....
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