Third International Scientific and Practical Conference “Eagles of the Palearctic: Study and Conservation”

Raptors Conservation. Suppl. 2. Proceedings of Conferences

Human activities can hinder the breeding of a top avian predator: preliminary results

Dobrev D.D., Dobrev V.D. (Bulgarian Society for the Protection of Birds / BirdLife Bulgaria, Plovdiv, Bulgaria)
Demerdzhiev D.A. (Bulgarian Society for the Protection of Birds / BirdLife Bulgaria BSPB, Plovdiv, Bulgaria)

Dobromir Dobrev
Vladimir Dobrev
Dimitar Demerdzhiev
Recommended citation: Dobrev D.D., Dobrev V.D., Demerdzhiev D.A. Human Activities Can Hhinder the Breeding of a Top Avian Predator: Preliminary Results. – Raptors Conservation. 2023. S2: 298–299. DOI: 10.19074/1814-8654-2023-2-298-299 URL:

Imperial eagle (Aquila heliaca, EIE) is a large-sized, globally threatened species with a wide distribution. The species is extremely vulnerable and sensitive to human disturbance and activities in the vicinity of its nests. We analyzed the effect of human disturbance on two territories of Eastern Imperial Eagles from Bulgaria in 2008–2009. We recorded 375 cases of different types of human activity in the vicinity of the two surveyed nests – 60 cases for nest A and 315 for nest B. The most common activity around the studied nests was the passing of light motor vehicles (n=100 cases). Our results highlight that the probability of EIE’s reaction is dependent on the type of activity, distance from the nest and the duration of the activity. However, eagles’ reaction is independent from the number of intruders. We found that with the decrease of the distance to the nest, the reaction progresses and is more acute. We found statistical differences between the distance belts and the majority of alert and flight reactions that were recorded at distances up to 300 m from the nests. We reported that humans walking around nests (mainly hunters, fishermen, tourists, people illegally extracting sand in the close vicinity of the nests) result in a large number of reactions of flight off by the eagles, thus leaving the nest unattended. More research on a large scale on this topic is needed, including more accurate measures to address human disturbance in EIE territories. The findings will be applied to ensure higher breeding rates and species conservation.