sentences:  However, almost certainly the leading cause of this species' decline was the practice of felling old trees on field boundaries that were the nest sites for the eagle.Among other reasons for its decline were the depletion (both incidental and intentional) of prey species and the incidental consumption by the eagles of poison baits, left out to eliminate wolves.As with other eagles in Eurasia, the Industrial revolution allowed access to poisons and firearms, which made the killing of eagles far easier and hastened their decline.