SPANISH IMPERIAL EAGLE

Order: Accipitriformes.
Family: Accipitridae.

68-83 cm.

180-220 cm.

In appearance, the only species that could be confused with the Spanish Imperial Eagle is the Golden Eagle. In general, the Spanish Imperial Eagle has a larger head and much darker tones than the Golden Eagle, which lacks white shoulders in its adult stage. In juvenile stages, it is the opposite: Spanish Imperial Eagles have plumage with brown/antler/cinnamon tones. On the other hand, juvenile Golden Eagles are very dark brown.

Both males and females have very similar plumage. However, there is a great overlap, so this variable is not valid for sexing specimens of this species. Generally, males tend to be smaller than females.

It is possible to recognize 5 different ages:

Juvenile specimen: the plumage of these specimens covers from leaving the nest to approximately 7-8 months of age. This first stage of plumage highlights reddish-brown to orange tones. In flight, the large coverts of the wings and rectrices are very visible, as well as all the flight feathers, since their terminal end is bathed in antler tones, generating a line or wing stripe appearance.

2nd/3rd year specimen: these individuals present plumage with greater wear and discoloration, producing a contrast between those worn feathers and those of the new generation. All the characteristic features of juveniles begin to disappear. Some individuals (although this is subject to great variability) may have some darker streaking in the upper chest area. Finally, in this phase of development, some more typical features of the preceding plumage may begin to emerge, showing darker areas on the head, throat, and in the region of the shoulder feathers, where in some specimens, it is already possible to find some white feathers that so characterize individuals of a higher age class.

3rd/4th year specimen: these individuals present (perhaps) the most complex phase, due to individual variability and the degree of feather molt progress, which must be taken into account to be as precise as possible, and that divides specimens into light or dark checkered patterns depending on the evolution of the plumage. The wing and body coverts display a dull yellowish-brown-blackish color, giving a checkerboard appearance. The throat and head acquire very dark tones, already characteristic of the definitive plumage. In some specimens, the characteristic white feathers on the shoulders begin to appear, in this case, they are very patent, being still not as clean white as in adults.

4th/5th year specimen: these individuals present much more homogeneous plumage, giving the impression of very dark individuals, always contrasting with the white feathers on the shoulders. Generally, they still retain some very worn feathers from previous generations, especially in the lower body areas. The white of the shoulder feathers is increasingly vivid and extensive, and the golden-yellow color of the pileus and nape also stands out, contrasting with the rest of the body.

Adult specimen: Adult specimens acquire their definitive plumage from 5 and a half or 6 years old, which is also very variable. Their appearance is very dark, except for the head and a considerable part of the neck, which obtain a yellowish-brown color, even more extensive and intense than in subadult specimens. The border of the shoulders is bathed in clean white. Grayish and barred rectrices, with a characteristic black terminal band.

Primaries: 10 per wing.
Secundaries: 18 per wing.
Rectrices: 12.