The eastern imperial eagle (Aquila heliaca) is a large bird of prey known for its impressive size and powerful talons. One of the key features that distinguishes this species is the size of its feet, particularly the hallux claw, which is larger than that of its cousin, the golden eagle.
The Size of an Eastern Imperial Eagle’s Foot
According to the information provided, the eastern imperial eagle has a relatively long and thick neck, a big head and bill, a longish square-tipped tail, somewhat long and well-feathered legs, and strong feet. The hallux claw, the enlarged rear talon that accipitrids (birds of prey) use for seizing and killing prey, is larger in the eastern imperial eagle compared to the golden eagle.
Specifically, the hallux claw (the enlarged rear talon) of the eastern imperial eagle has been measured to be between 38 and 43 mm (1.5 and 1.7 inches) in length for female birds. In comparison, the smallest talon measured for an immature male golden eagle was 44.9 mm (1.77 inches).
This difference in the size of the hallux claw can be used to reliably distinguish the eastern imperial eagle from the golden eagle, as the eastern imperial eagle’s claw is larger.
Comparison to the Golden Eagle
Image source: eastern imperial eagle By Koshy Koshy
To further illustrate the size difference, the eastern imperial eagle is typically the largest, with the largest extremities (i.e., tarsal, tail, and bill length) and most powerful booted eagle species in the majority of its range, apart from its rare African winter quarters in South Asia, where it rivals a fish eagle as the largest and most dominant eagle species.
In contrast, the golden eagle, which is the wider-ranging cousin of the eastern imperial eagle, has a smaller hallux claw. The smallest talon measured for an immature male golden eagle was 44.9 mm (1.77 inches), while the eastern imperial eagle’s hallux claw has been measured at 38 and 43 mm (1.5 and 1.7 inches) for female birds.
Overall Size and Measurements
In terms of overall size, the eastern imperial eagle has a total length ranging from 68 to 90 cm (27 to 35 inches) with a typical wingspan of 1.76 to 2.16 m (5.8 to 7.1 feet). Males usually weigh between 2.45 to 2.88 kg (5.4 to 6.3 lb), while females weigh between 3.26 to 4.54 kg (7.2 to 10.0 lb).
The table below summarizes the key measurements of the eastern imperial eagle:
| Measurement | Range |
|---|---|
| Total Length | 68 to 90 cm (27 to 35 inches) |
| Wingspan | 1.76 to 2.16 m (5.8 to 7.1 feet) |
| Male Weight | 2.45 to 2.88 kg (5.4 to 6.3 lb) |
| Female Weight | 3.26 to 4.54 kg (7.2 to 10.0 lb) |
| Hallux Claw Length (Female) | 38 to 43 mm (1.5 to 1.7 inches) |
In conclusion, the eastern imperial eagle is a large and powerful bird of prey, distinguished by its impressive size and the large size of its hallux claw, which is larger than that of its cousin, the golden eagle. This difference in the size of the hallux claw can be used to reliably identify the eastern imperial eagle.
References:
- https://www.thainationalparks.com/species/eastern-imperial-eagle
- https://en.wikipedia.org/wiki/Eastern_imperial_eagle
- https://en.wikipedia.org/wiki/Golden_eagle
- https://snco.org/bird-spotlight-central-oregons-eagles/
