The Eastern Imperial Eagle (Aquila heliaca) is a large bird of prey that breeds in southeastern Europe and extensively through West and Central Asia. It is a member of the Aquilinae subfamily, characterized by feathered legs. This species is known for its unique plumage patterns that change as the bird matures, making it an intriguing subject for birdwatchers and enthusiasts.
Identifying the Eastern Imperial Eagle
Size and Appearance
The Eastern Imperial Eagle is a large eagle, typically measuring between 68 to 90 cm (27 to 35 inches) in total length, with a wingspan ranging from 1.76 to 2.2 m (5 ft 9 in to 7 ft 3 in). Females are generally larger than males, with up to a 10% difference in linear measurements and a 40% difference in body mass.
Plumage Patterns
The Eastern Imperial Eagle undergoes several plumage changes as it matures, which can be used to identify the bird’s age and stage of development:
- Juvenile: The juvenile has a reddish, rusty-toned plumage.
- “Straw-colored”: As the plumage becomes worn and discolored, the bird takes on a yellowish or golden “straw-colored” appearance.
- “Pale Chess”: The bird begins to acquire new, orange-toned feathers, creating a checkered pattern with the remaining pale yellow feathers.
- “Dark Chess”: When the plumage has more than 50% dark feathers, it is called the “dark chess” phase.
- Subadult (Imperfect Adult): The plumage is dark brown, almost black, with some lighter remnants of the previous plumage and visible white shoulders.
- Adult: The definitive adult plumage is virtually black, with golden feathers on the posterior part of the head and neck. A white border, of variable size, delimits the wings from the shoulders and/or scapular region. The base of the tail is light grey with a broad black terminal band.
Habitat and Behavior
The Eastern Imperial Eagle is an opportunistic predator, primarily selecting small mammals as prey, but also feeding on birds, reptiles, and carrion. It prefers the interface of tall woods with plains and other open, relatively flat habitats, including the wooded mosaics of the steppe. Nests are typically located in large, mature trees, and the parents raise around one or two fledglings.
Conservation Status
Image source: eastern imperial eagle By Koshy Koshy
The global population of the Eastern Imperial Eagle is small and declining due to persecution, loss of habitat, and prey depletion. As a result, the species has been IUCN Red Listed as Vulnerable since 1994.
Conclusion
The Eastern Imperial Eagle is a fascinating and unique bird of prey, with its distinctive plumage patterns and adaptations to its preferred habitat. Understanding the identification characteristics of this species is crucial for birdwatchers and conservation efforts. By learning to recognize the Eastern Imperial Eagle, we can better appreciate and protect this vulnerable species.
