Evaluation of habitat suitability and migratory paths of an endangered raptor, Steppe Eagle (Aquila nipalensis) in Iran

Abstract

Understanding habitat suitability, the environmental variables limiting the distribution of species, and migratory paths are important issues for conservation of threatened bird species. Identifying areas important for birds and their overlap with conservation areas (CAs) can guide conservation managers in establishing new CAs. The Steppe Eagle (Aquila nipalensis) is a globally endangered winter visitor raptor in Iran. We used 164 occurrence records of Steppe Eagles and data on 12 environmental variables in Iran as input to ensemble modeling and electrical circuit theory models to identify, respectively, potential wintering areas and migratory paths between those wintering areas. Our results revealed that elevation, distance to rodents, mean diurnal range, distance to villages, and distance to cities were the most influential variables for habitat suitability in Iran. Potential wintering areas identified by our models were mainly located in the north and south of Iran and migratory paths connected these areas through the central plains. CAs covered about one-fifth of potential wintering areas. Conservation of the species within potential wintering areas and the migratory paths from northern to southern Iran is necessary for the survival of this endangered species in its entire distribution. Therefore, wildlife managers should pay increased attention to non-protected parts of potential wintering areas in order to establish new CAs and protect migration paths against threats. Our results pave the way for proper planning for the conservation of threatened raptors in Iran, particularly Steppe Eagle.