The First Record of Case of the Imperial Eagle and the Steppe Eagle Successful Breeding in the Mixed Pair in Western Kazakhstan and Records of Probable Hybrids of These Species in Russia and Kazakhstan

Abstract

Facts mentioned in paper give evidence of the possibility of forming the mixed pairs between Steppe and Imperial Eagles, breeding success and fertility of hybrids. All the observed mixed pairs were found in the contact zone of the two species on the periphery of the Steppe Eagle breeding range under conditions of either decrease in numbers of one species (Steppe Eagle) and the growth of another (in Western Kazakhstan), or decline in numbers of both species and the lack of birds of their own species (in Dauria). Considering the fact that the number of Steppe Eagles continues to decline, the hybridization process may amplify and this phenomenon requires a more thorough examination.

Keywords

• raptors
• birds of prey
• Steppe Eagle
• Aquila nipalensis
• Imperial Eagle, Aquila heliaca, hybrids