DIFFERENTIATING EAGLES FROM OSPREYS
Both the eagle, the osprey are raptors or birds of prey. Raptors are highly specialized birds to hunt and take down animals that are relatively larger than they are. Both ospreys and eagles are physically gifted with good eyesight, which includes excellent depth perception so that they can easily detect prey from long distances or high altitudes. As with the other raptorial birds, Eagles and ospreys possess strong gripping claws–talons–to hold on to prey. They both possess strong beaks for ripping through meat, muscle, and connective tissue. Because of their status as apex predators, some eagles and ospreys have also been domesticated in early civilizations as hunting animals, dogs, and big cats.
But there are also obvious differences between an eagle and an osprey. Here are some of the differences.
1. SIZE
Depending on the variety, eagles are generally larger than ospreys. But not by much. The golden eagle, which is the most common and most distributed species–has a wingspan of about 2.3 meters when fully mature. It can weigh somewhere between 4 to 7 kilograms. The length of its body is approximately 100 cm.
An adult osprey weighs approximately 1.5 kilograms and grows to about 65 cm. In comparison, an osprey has an average wingspan of 2 meters. Both the osprey and the eagle are classified as large raptors.
2. APPEARANCE
Eagles appear to be physically powerful. Females are generally larger than males. And they have the attributes to support this impression. Everything about the eagle exudes strength. They have large and prominent heads, large beaks, stout wings, and a sturdy and powerfully built body. Their beaks are hooked, enabling them to tear flesh from bone with relative ease. Their taloned feet are always coiled even in flight, ready to snatch prey and then tear at them after a successful chase. Their eyes are very large and very round, nearly 4 times the potency of human eyesight.
Male and female ospreys are similar in size and appearance. But males can be distinguished through their slender physique and narrow wings. Ospreys have black beaks and black talons. Males also lack the more visible and more pronounced white band of feathers that can be seen on the female’s underside and belly. When they fly, the wings of ospreys tend to resemble human hands. Unlike eagles, ospreys are noisy raptors with their distinct whistle-type of vocalization.
3. HABITAT
Eagles are found in North and South America. In Asia, they are found in New Guinea and the Philippines. The Philippine eagle is considered to be the largest eagle in terms of body length and wingspan. Eagles prefer to live in secluded forests or high cliffs, as long as these terrains are near bodies of water where prey is abundant. They build their nests in sharp crags high on cliff walls or in the tallest trees in the forest canopy. Aside from humans, eagles have no natural predators. In their respective habitats, they are at the top of the food chain.
Unlike eagles which have limited distribution, ospreys are found in all continents except Antarctica. They are concentrated mostly in temperate and tropical territories. Except in Australia, ospreys are migratory during the onset of cold climate. They frequent open areas near freshwater, brackish water, and saltwater. They prefer estuaries and marshes where there are large concentrations of both water-dwelling and land-dwelling prey.
4. DIET
Fish is the main diet for ospreys. Unlike other raptors, which prefer to kill prey before eating them, ospreys consume their prey alive. When they fish, they rely on their keen eyesight to detect fish swimming just near the surface. They would then either at a very steep nosedive at great speed. It pulls up at the last moment, its feet breaking the water surface in a spectacular splash as it grips the fish.
In some cases, it will even dive in completely to a depth of about 1 meter before quickly pulling up with its catch. This is the frequent method it employs. Another time, it glides gracefully and snatches the fish in one fluid and graceful movement that barely disturbs the surface of the water. Ospreys eat fish native to their habitat. These may be salmon, trout, perch, and flounder. But they would also supplement their fish-heavy diet with other meats such as reptiles, smaller birds, and small mammals such as mice.
Eagles are powerful apex predators who are capable of hunting a wide variety of prey. They prefer fish primarily, followed by birds and fowls, and then mammals. They are known to hunt chicken in farms and rural areas that are near their natural habitats. They have been known to even hunt and eat cats. When food is scarce, eagles can also switch from being active apex predators to carrion feeders.
5. INTERACTION WITH HUMANS
Ospreys adapt well to the human presence. They are not quite bothered by the proximity to humans, much to their detriment. Many documented and reported cases of ospreys collide with power lines, causing death by electrocution. There are also frequent collisions between ospreys in flight and motor vehicles on highways. Because their primary diet consists of fish, water pollution is a threat to their existence. Industrial waste has introduced significant volumes of mercury, arsenic, and lead. Since fish ingest these, they also are indirectly consumed by ospreys.
In contrast, eagles react adversely to human encroachment. Since they prefer the safety of isolated forests and hard-to-reach cliffsides, they are very intolerant of incursions. One particular trait of all eagles is that they will abandon their nests when they realize it has been disturbed.
6. BEHAVIOR
Ospreys are monogamous and generally mate for life. The male takes the responsibility of choosing a safe and ideal site where the pair can build a nest and lay eggs. Their choice of nesting sites can be quite interesting. They can choose a high cliff, a church steeple, or even power lines and telephone poles. Once the preferred site is chosen, the pair shares the responsibility of gathering materials for the nest. Both males and females gather debris such as twigs, vines, and other materials. Then, the female takes over and builds the actual nest. Once the eggs are laid, the male and the female osprey take turns in incubating. Osprey chicks are known for intensely competing with each other for food. They stay with their parents for about four months until they are physically capable of hunting food independently.
Except for ospreys in Australia, ospreys fly long distances when they migrate to breed. Their migration season is usually during the first half of the year, from January to May.
As apex predators, eagles generally avoid too much activity; They need to conserve their energy between hunts. The golden eagle, for example, rests on the same spot for most of the day, doing nothing. They spend about a total of four hours of daylight hunting and spend the rest perched. They sleep soundly through the night. In terms of social behavior, eagles are solitary by nature. But they also form breeding pairs. They are relatively intolerant of their fellow eagles. But when cold weather arrives, golden eagles forego their solitary nature and perch together for safety and warmth.
Unlike migratory ospreys, eagles are sedentary. They rarely make long flights.
7. EVOLUTION
As is the case among all avians, eagles and ospreys are descended from prehistoric reptiles and dinosaurs. Eagles are the descendants of an ancient line of carrion feeders and fish predators called kites. The actual eagles evolved from these ancient kites about 36 million years ago. The sea eagles are thought to be the oldest of the eagles because their hunting and feeding behaviors closely resemble those of their kite ancestors.
As fellow birds of prey, ospreys may have a similar evolutionary lineage with the ancient reptiles and dinosaurs, But they are completely different from eagles.
QUESTIONS AND ANSWERS ABOUT RAVENS AND ROOKS
CAN OSPREYS BE DOMESTICATED AND TRAINED?
No. But there are a few rare cases. But these are more exceptions than rules. Although they are tolerant of humans, they cannot be domesticated and trained similarly to falcons and hawks. Their instinct to immediately feed on live prey while on high perch are a sharp contrast to the aim of falconry, where the hunting bird is trained to stay on the same ground where it caught its prey.
CAN EAGLES BE DOMESTICATED AND TRAINED?
Yes. Being the most distributed eagle species, the golden eagle has been the object of domestication and training by hunters. They are prized for their ability to see prey over long distances. The practice of training golden eagles for the hunt is a time-honored tradition in Mongolia. Due to the ubiquity of the golden eagle with Mongolia’s ancient warrior culture, it has become one of its national mascots and emblems.
DO EAGLES KILL OSPREYS?
Yes. There are cases of eagles hunting young ospreys or raiding their nests for the chicks.