Double Crested Cormorant \"Are Opportunistic, Generalist Feeders\"

Double Crested Cormorant "are opportunistic, generalist feeders" (Wires, Cuthbert, Dale, & Joshi, 2001). They feed on slow moving fish species that range from 3 centimeters to 40 centimeters. These birds forage in shallow water and seem to be strict diurnal in the way they eat. They are quick to respond to areas with high fish concentration and flock where the fish can easily be caught.

The Double Crested Cormorant breeds in cold climatic conditions and has been living in Alaska for a long time (Wires, Cuthbert, Dale, & Joshi, 2001, p. 36). According to Siegel-Causey & Savinetskii (1991), the remains of the bird have been found on Amchitka Island dating back over 2000 years. These remains suggest that the there were plenty of the species in the central Aleutian Islands and climate changes have reduced their population in Alaska.

Great Blue Herons

Great Blue Herons are prey generalists, although they forage for fish. They catch their prey as they walk along the shores of water bodies such as oceans, lakes, marshes and even rivers. On the mainland, the bird preys on small animals such as rodents (Butler, 1992). The mainland foraging is done in the winter when the shores are frozen and fish is unavailable, or when the young ones are learning hunting skills (Butler, 1991). The Great Blue Herons also prey on amphibians, reptiles, invertebrates and birds. They catch their prey by a quick head and neck thrusts.

Great Blue Herons breed in various regions of the world, but in North America, the Ardea Herodias occidentalis are found in the warmer regions such as Florida. "The Herodias fannini are non-migratory found in the Pacific coast from Washington States to Alaska and Herodias found between south Canada to Galapagos" (Butler, 1992). The size of the colony on all these species depend on foraging area.

Wood Stork

Wood storks are specialists. They have a specialized eating behavior known as tactolocation, they walk through the water with beaks open and immersed in the water. When they feel the preys, they snap the beaks raise them up and swallows (Kushlan, 1977). Their peculiar feeding behavior allows them to feed at night, but for them to do this, the prey must be highly concentrated.

The wood stork is found in fresh water lakes, oceans and estuarine habitats ( Patuxent Wildlife Research Center information on Migratory Bird, 2011). They construct their nest in the middle of trees that are located in swampy areas or islands. Wood storks are found in areas with reasonable amount or rainfall such as Florida during autumn. The estuarine areas are vital for their feeding habitats for them.

American Robin