MuskratThe muskrat (Ondatra zibethicus) is a medium-sized semiaquatic rodent native to North America and an introduced species in parts of Europe, Asia, and South America. The muskrat is found in wetlands over a wide range of climates and habitats. It has important effects on the ecology of wetlands, and is a resource of food and fur for humans. Adult muskrats weigh , with a body length (excluding the tail) of . They are covered with short, thick fur of medium to dark brown color.
RodentRodents (from Latin rodere, 'to gnaw') are mammals of the order Rodentia (rouˈdEnS@), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are native to all major land masses except for New Zealand, Antarctica, and several oceanic islands, though they have subsequently been introduced to most of these land masses by human activity.
American alligatorThe American alligator (Alligator mississippiensis), sometimes referred to colloquially as a gator or common alligator, is a large crocodilian reptile native to the Southeastern United States. It is one of the two extant species in the genus Alligator, and is larger than the only other living alligator species, the Chinese alligator. Adult male American alligators measure in length, and can weigh up to , with unverified sizes of up to and weights of making it the second largest member of the family Alligatoridae, after the black caiman.
Introduced speciesAn introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there by human activity, directly or indirectly, and either deliberately or accidentally. Non-native species can have various effects on the local ecosystem. Introduced species that become established and spread beyond the place of introduction are considered naturalized.
Potomac RiverThe Potomac River (pəˈtoʊmək) is a major river in the Mid-Atlantic region of the United States that flows from the Potomac Highlands in West Virginia to the Chesapeake Bay in Maryland. It is long, with a drainage area of 14,700 square miles (38,000 km2), and is the fourth-largest river along the East Coast of the United States and the 21st-largest in the United States. Over 5 million people live within its watershed. The river forms part of the borders between Maryland and Washington, D.C.
WetlandWetlands, or simply a wetland, is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The primary factor that distinguishes wetlands from terrestrial land forms or water bodies is the characteristic vegetation of aquatic plants, adapted to the unique anoxic hydric soils.
BeaverBeavers (genus Castor) are large, semiaquatic rodents of the Northern Hemisphere. There are two existing species: the North American beaver (Castor canadensis) and the Eurasian beaver (C. fiber). Beavers are the second-largest living rodents, after capybaras, weighing up to . They have stout bodies with large heads, long chisel-like incisors, brown or gray fur, hand-like front feet, webbed back feet, and tails that are flat and scaly. The two species differ in skull and tail shape and fur color.
