The Tawny Eagle (Aquila rapax) and the Steppe Eagle (Aquila nipalensis) are two majestic birds of prey that share similarities, yet possess distinct differences in their morphology, anatomy, behavior, and distribution. This comprehensive blog post will delve into the intricacies that set these two eagle species apart.
Morphological and Anatomical Distinctions
Size
One of the primary differences between the tawny eagle and the steppe eagle is their size. Steppe eagles are larger, with males measuring 69-81 cm (27-32 in) in length and having a wingspan of 170-200 cm (67-79 in). Females are even larger, with a length of 74-94 cm (29-37 in) and a wingspan of 190-220 cm (75-87 in). In contrast, tawny eagles are smaller, with a length of 60-75 cm (24-30 in) and a wingspan of 159-190 cm (63-75 in).
Plumage
The plumage of these two eagle species also differs. Tawny eagles have tawny upperparts and blackish flight feathers and tail, with a very pale lower back. They are smaller and paler than steppe eagles, but do not share the latter’s pale throat. Immature birds of both species exhibit less contrast in their plumage compared to adults, but both show a range of variation in color.
Gape
Another distinguishing feature is the size of the gape, or the width of the mouth. The gape of a steppe eagle is much wider than that of a tawny eagle, extending to the back end of the eye, whereas a tawny’s gape only extends to the middle of the eye.
Behavioral and Ecological Differences
Image source: Tawny Eagle by Bernard DUPONT
Habitat
Tawny eagles are residents of India, Africa, and southwestern Asia, preferring open dry habitats such as desert, semi-desert, steppes, or savannah. Steppe eagles, on the other hand, breed in grassland in Siberia and are migratory, wintering in Africa, India, and the Middle East.
Diet
Both species are carrion feeders, but tawny eagles also prey on small mammals, reptiles, and birds, while steppe eagles mainly feed on fresh carrion of all kinds.
Nesting
Tawny eagles breed year-round, with peak breeding generally in the winter months. They lay 1-3 eggs in a stick nest in a tree, crag, or on the ground. Steppe eagles, on the other hand, breed in grassland in Siberia and lay 1-3 eggs in a stick nest on the ground or in a tree.
Conservation Status
The conservation status of these two eagle species also differs. Tawny eagles are listed as “Vulnerable” on the IUCN Red List, while steppe eagles are listed as “Endangered”.
Conclusion
The Tawny Eagle and the Steppe Eagle are two fascinating birds of prey that share many similarities, yet possess distinct differences in their morphology, anatomy, behavior, and distribution. Understanding these differences is crucial for conservation efforts and for appreciating the diversity of the avian world.
