For the first time, in an artificial nest placed in the region of Slavonia and Baranja, Croatia, a pair of the very rare and endangered Saker Falcon (Falco cherrug) was observed making a hole to lay eggs!
Presents our expert: Ms. Marija Vereš Expert Advisor and Project Manager of LIFE Danube Free Sky in Public Institution Kopački rit Nature Park
Ms. Vereš, tell us why this is of such importance.
Saker Falcon is a strictly protected species, and the nesting population in Croatia is critically endangered. Since our area represents the largest border of Saker´s breeding population in Europe, they are very rare, with a national breeding population of less than 5 pairs. Saker Falcons used to nest near Kopački rit on the power line pylon but stopped about 10 years ago. These artificial nest boxes have a video system that allows us 24-hour monitoring of activity in the nests, so it´s very helpful for learning about the ecology and behavior of the species itself.
How did you create that nest, and do you have other such nests?
Nest boxes were installed as part of the LIFE Danube Free Sky project in February 2023. A total of 3 nest boxes were installed on the distribution line in cooperation with the HEP Distribution system operator, who is also a project partner on Danube Free Sky. The nest boxes are oriented south to protect from harsh north winds. Also, the nest boxes are filled with gravel. Saker Falcons don´t build their nests but rather occupy abandoned raven, crow, or even eagle nests. The bottom of the nest boxes is perforated to allow drainage of excess water through gravel. In 2023, one of the nest boxes was occupied by Common Kestrels, another strictly protected species. In 2024, two nest boxes were occupied by Kestrels, and an immature Saker Falcon was observed near one of the nest boxes in August. In February of this year, the first Saker was spotted on the nest, and two weeks later, another one showed up. Pair is regularly visiting the nest box and has started preparing the nest by making and fixing a hole where the female will(hopefully) lay eggs. That should happen in the next few weeks.
What are the long-term expectations for the success of the LIFE Danube Free Sky project?
LIFE DanubeFree Sky project started in 2020 and will last until 2026. In the project area in Croatia, we have already implemented all mitigating measures to prevent collision and electrocution of birds in interaction with power lines. HEP DSO installed more than 550 bird flight diverters on power lines where nest boxes are installed. These diverters have elements that reflect light while spinning, which helps birds to spot wires and avoid hitting them. HEP also replaced 40 km of existing wires with a new semi-isolated type that is more visible, thus preventing both collision and electrocution at the same time. As part of the project, HEP also installed protective elements on 96 transformer stations that were also dangerous because of the risk of electrocution. Another partner from Croatia, HOPS – a transmission system operator, installed more than 1000 bird flight diverters on their transmission lines. All these implemented activities are making the area of Kopački rit and its surroundings safer for birds, especially during their migration.
What does working on this project and the conservation of the Saker Falcon mean to you personally?
This was my first role as project manager, so I didn´t know what to expect when the project started. As the project progresses, it has helped me not only in my professional development but also in understanding the threat the power grid poses to birds. Working on the project has brought me wonderful collaborations with experts from different sectors who share a common vision for bird protection. I also try to raise awareness of this issue among the people around me. The potential return of the Saker Falcon is just the icing on the cake and confirmation that hard work pays off when we work together.
Do you intend to continue implementing this type of activity after the project is completed, and what are your options for further financing?
There are already plans for a follow-up project in which we would like to continue with implementing good practices on other dangerous lines that weren't part of Danube Free Sky.
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For more information please contact Ms. Marija Vereš (Expert Advisor and Project Manager of LIFE Danube Free Sky in Public Institution Kopački rit Nature Park): marija.veres[at]