Bald Eagle

The Bald Eagle is found only in North America. It lives along the sea coast and near large rivers and lakes feeding mostly on fish. Nowadays, the population of Bald Eagles is out of danger, but in the middle of the 20th century they were on the brink of extinction. There were several threats to their population: habitat destruction, excessive hunting, and chemical contamination of their food. Being at the top of the food chain, Bald Eagles are very vulnerable to pesticides concentrated in animals and fish.

For a long time, humans thought that the Bald Eagle poses a threat to salmon population and to domestic cattle. The fact is that Bald Eagles cannot prey upon domestic stock, because they are not strong enough to lift it. As for competition for fish and other prey, eagles take only the weakest individuals, thus improving the general health of the population.

The Bald Eagle is perfectly adapted to flying at great altitudes. They are able to get to the altitude of 10,000 feet. The skeleton of an adult eagle consists of hollow bones that weight from 250 to 300 grams, which averages 5-6% of the bird’s body mass. The talons, beak and feathers of the Bald Eagle are made of a very light-weight keratin. The feathers weigh twice as much as the skeleton. Long feathers on the tips of the wings are widely separated in flight to reduce turbulence. When soaring, eagles don’t flap their wings, but rely on their length and firmness. To attain the largest surface area, Bald Eagles spread out their tail feathers. The tail is also used for maneuvering and stabilization during dive and swoop toward prey.

To fly for hours at a high altitude, the Bald Eagle should be protected from cold. The dense down and coarse outer feathering of these birds is a good insulation against cold and rain. Their feet are tendon and don’t feel cold. In flight, Bald Eagles maintain their body temperature by changing the position of the feathers. When soaring early in the morning, eagles rotate their feathers so that the air pockets are drawn together; in a hot midday, the air pockets are opened to cool down. For better insulation, the Bald Eagle has several layers of feathers.