Eastern American Subregion

(Allegheny subregion), a subregion of the Holarctic zoogeographic region of the land. Occupies the eastern part of North America from approximately 100° E long, on the east and to the south of the southern boundaries of the Canadian subregion—that is, from approximately 45° N lat. The subregion encompasses the gigantic Mississippi basin, the low-mountain regions in the east (the Alleghenies and Appalachians), as well as all of Florida and the Bermuda Islands.

The major portion of the eastern American subregion is flat or hilly, with a moderately warm, rather humid climate. Leafy forests, which pass into the taiga forests of Canada in the north and subtropical and tropical vegetation in the south (southern Florida), are predominant there. A significant area, particularly in the west, is occupied by steppes, which pass into the arid expanses of the central and western parts of the continent.

The fauna of the subregion is rich and diverse; the typical fauna of the Nearctic is most vividly expressed there. However, the number of endemic forms is relatively small; among the mammals such forms include certain shrews (for example, of the genera Blarina and Cryptotis) and moles (the star-nosed mole and the genus Scalopus). Such animals of southern origin as the ocelot, jaguars, and armadillos are found only in this subregion. The opossum and certain other mammals that are almost completely confined to this subregion are widely encountered. Certain species of small rodents, particularly of the genus Peromyscus, are typical. Among the many species of birds, the wild turkey, prairie chicken, fork-tailed harrier, Java sparrow, parrot, and a number of aquatic birds such as the flamingo, the South American darter, pelicans, and herons are particularly characteristic. Reptiles include the alligator and American crocodile and a number of species of turtles (including the alligator snapper), lizards, and snakes. Typical amphibians include the fishlike salamanders, two-legged salamanders, the Allegheny hellbender, and certain frogs. Relict forms offish, such as the long-nosed gar, the bowfin, the shovel-beaked sturgeon, and the paddlefish, are also found. The fauna of the subregion, like all of nature, has been greatly altered by man’s activity.

Certain scientists do not distinguish the eastern American subregion in the zoogeographic zoning of dry land, considering this territory to be a province of the Sonoran subregion.