USGS Bird Population Essay Example | Topics and Well Written Essays - 250 words

USGS Bird Population - Essay Example Indeed, it found as far north as Alaska on the west coast as well as New England on the east coast and as far south as Mexico and the Bahamas. It is also found in eastern Canada, in Great Britain, and Ireland. Its ability to survive on a variety of diets, which include fish, amphibians and crustaceans, also indicate that the Double Crested Cormorant is a generalist. The Great Blue Heron is also a generalist/opportunistic species. This species is found not only in freshwater and saltwater habitats but also in mangrove swamps, flooded meadows, lake edges as well as along the shoreline. Indeed, it thrives in almost every part of North America, from Alaska and southern Canada in the North to Florida, Mexico and the Caribbean in the south. It is also found in South America, Greenland and England (Elliott, del Hoyo, Sargatal, & Imboden, 1992). Though the primary food of the Great Blue Heron is fish, it opportunistically feed on a variety of aquatic organisms such as shrimp, crabs, insects, rodents, amphibians, reptiles and other smaller birds. The Wood Stork is an example of a specialist given that it is found in limited habitat mainly tropical and subtropical climates of South America, Central America and the Caribbean. It is also found in subtropical climates of the United States such as in the States of Florida, Georgia and South Carolina where they live on cypress trees in marshes and swamps (Ehrlich, Dobkin, & Wheye, 1992). The Wood Stork, which is an endangered species (Ehrlich, Dobkin, & Wheye, 1992), preys on a limited variety of aquatic organisms that include fish, frogs and large insects. The America Robin is indeed a generalist that is found in almost all parts of North America, from Alaska and Canada in the North to Florida and Mexico in the south (The Cornell Lab of Ornithology, 2011). Thus is can survive in different types of environments though its habitat is mainly woodland. It is also found in the Caribbean, Greenland, and in