An interesting chapter in the history of these animals began in 1905, when four Canadian muskrats were introduced on a nobleman’s estate in Bohemia. Since then they have increased rapidly and spread over a large area in Bohemia and beyond its borders. The streams in the region they occupy are controlled by grassy banks, and dams are built to form ponds for fish culture, which is a large industry there. The muskrats persistently tunnel into the banks and dams, causing them to give way, thus causing heavy losses to the owners.
They also work havoc among river crabs and mussels, which have great economic value, and interfere with the fish and their spawning beds. To cap the climax of their misdeeds, they are reported to feed on grain and vegetables and to destroy the eggs of domestic poultry and of wild-fowl. It is reported also that these expatriates in their foreign environment have become larger animals than their ancestors, and that their fur has greatly deteriorated in quality. The measures prescribed by the Agricultural Council of the Kingdom of Bohemia for their control are apparently without much success. This instance is a good illustration of the danger attending the introduction of an animal from its native habitat into a new region.
THE WOODRAT (Neotoma albigula and its relatives)
(For illustration, [see page 526])
In the East known as woodrats, in the West, where much more numerous and better known, these animals are called “mountain rats” or “trade rats.” Despite a certain superficial resemblance in size and appearance, woodrats are not related to those exotic parasites, the house rats, with coarse hair and bare tails, but are far more attractive and handsome animals, clothed in fine soft fur, delicately colored above in soft shades of gray, buffy, or ferruginous, while below they are usually snowy white or buffy. The tail is fully haired and in some species almost as broad and bushy as that of a squirrel. Their prominent black eyes and large ears give them an air of vivacious intelligence which their habits appear to confirm.
Woodrats are peculiar to North America, where they occur from Pennsylvania and Illinois to the Gulf coast, spreading thence to the Pacific and as far north as the headwaters of the Yukon, and south through Mexico and Central America to Nicaragua. They are not plentiful in the southern Mississippi Valley and eastward, where they live among cliffs and broken ledges of rock in the deciduous forests, and well deserve their common name. In this region their presence is rarely suspected except by hunters or others familiar with woodland life.
Far more numerous and widely known in the Western States and throughout most of Mexico, they have adapted themselves to life under every climatic condition, from the most sun-scorched deserts of the southwest and the splendid redwood forests of the humid coastal region in northern California to the tropical lowlands farther south.
They live nearly everywhere on the mountain slopes, even to timber-line at 13,800 feet on Mount Orizaba. They thrive in an extraordinary variety of situations, not only where they may find shelter among rocks, but also where they must seek safety in nests made on the surface of the ground or in burrows dug by themselves. They are prolific animals and each year have several litters containing from two to five young.
The presence of woodrats is generally indicated by accumulations of odds and ends filling the crevices of the rocks about their retreats or piled about the entrances of their burrows, such accumulations including small sticks, pieces of bark, leaves, cactus burrs, bones, stones, and any other small objects which may be found in the vicinity.
Sometimes these piles of fragments seem to be made merely for amusement or to work off surplus energy, as they form useless gatherings, such as heaps of small stones, frequently containing a bushel or more, piled on the rounded tops of small protruding boulders in open desert areas, or small heaps of sticks and other material scattered aimlessly about their haunts.