Bird Species, Generalist and Specialist Double Crested Cormorant (Phalacrocorax auritus) Double Crested Cormorant is a member of the cormorant family of seabirds. Assuming that generalist/opportunistic species are widespread and more or less uniformly distributed, Double Crested Cormorant can hardly be categorized as generalist (Generalist an organism able to utilize many food sources, and therefore able to flourish in many habitats), as the bird may occur along inland waterways and coastal areas, but cannot inhabit deserts and territories far removed from the places, which furnish its food supply (The USGS Bird Population 2007).
This bird may winter in any place with no ice (for example, in southern Alaska or southern New England).
Its habitat may include almost all countries, as it can be found in Mexico, Bahamas, Europe, Great Britain, and Canada. Double Crested Cormorants diet includes fish, and sometimes amphibias and crustaceans. From here it may follow that Double Crested Cormorant can rather be categorized as an opportunistic than a generalist specie. Great Blue Herron Great Blue Herron is also referred to as Sandhill Crane or Blue Crane.
Great Blue Herrons diet includes frogs, fishes, the like, and crawfish. The birds nests are usually found in trees along the rivers. To a certain extent, Great Blue Herron can also be categorized as generalist specie, as it may inhabit various territories, being a common bird. It can be found singly or in colonies, and its habitat ranges from the Arctic regions to South America and the West Indies. Yet, the bird rarely occurs in the territories far removed from water districts, such as ponds or streams, where the bird can find its food supply. From here it follows that Great Blue Herron also can rather be categorized as an opportunistic specie, although it is much more habitat generalists while, for example, Wood Storks are more opportunistic. Wood Stork (Mycteria Americana) Wood Stork is a member in stork family Ciconiidae.
The Essay on Humming Birds Wings With Great Power As The Hummingbirds
Hummingbirds in Flight Hummingbirds are fascinating birds that are always fun to watch. These birds are able to hover in mid-air, dart from side to side, go straight up or down, or even backwards. They can out-fly and out-maneuver birds hundreds of times their size. There are many factors that contribute to the hummingbirds' ability to fly so easily through the air. A hummingbird's wings are ...
This tropical specie inhabits in freshwater and brackish lowland wetlands with trees. The bird nests in mangrove or cypress swamps (about 60 feet off the ground in the trees), and feeds in narrow tidal creeks, freshwater marshes, or flooded tidal pools (Terres 115).
It occurs in mainly Central America, South America, and the Caribbean. As a Wood Stork is a large water bird, its diet includes fish prey, tadpoles, and crayfish. From here it follows that as far as Wood Stork is unable to utilize many food sources, and therefore, is unable to flourish in many habitats, it is rather opportunistic than a generalist specie. American Robin The American Robin (Turdus migratorius) is a member of the thrush family.
The bird occurs in all sorts of woodlands and more open urban and farmland territories. The American Robins populations are quite stable and even increasing throughout its range. The American Robins habitat is North America (from Canada and Alaska to the north of Florida and Mexico).
The bird eats various types of food depending on the daytime. The birds diet generally includes about 40 percent invertebrates (for example, caterpillars, beetle grubs, and grasshoppers), and 60 percent berries and fruits. The bird eats soft-bodied invertebrates and worms, along with the mixture of both cultivated and wild fruits and berries. Taking into account the places, where the American Robin is able to inhabit, along with its diet, and precipitation, it is possible to conclude that the bird is rather generalist specie than an opportunistic one.
Works Cited Terres, John K. The Audubon Society Encyclopedia of N. American Birds. New York: Alfred A. Knopf, Inc., 1987. The USGS Bird Population .
28 August 2007 ..
