As the new year begins, various volunteer actions start as well, including the monitoring of the Eurasian Eagle-owl (Bubo bubo).

The Eurasian Eagle-owl, chosen as the 2022 bird of the year in Croatia, is the largest European owl, with a wingspan of up to 170 cm. It mainly inhabits coastal and mountainous regions of the country, and its habitat includes steep cliffs and open areas. It nests on hard-to-reach locations including cliffs, caves, and quarries. Although it is harder to see this bird due to its nocturnal behaviour, its distinctive calls can be easily heard at dusk and during the night.

Monitoring takes place throughout Croatia during February and March as pairs of owls stay near the nests during these months.

Volunteers will be educated on the subject and prepared to collect data on the distribution and nesting of this species, therefore contributing to its better protection. Last year, through a similar volunteer action, 97 locations were visited, and the nesting of 52 pairs was confirmed.

Volunteer monitoring of the Eurasian Eagle-owl is an example of citizen science and is one of the few such activities in Croatia that collects data for scientific research. In 2022, Laurus, the scientific journal of the Institute for Ornithology of the Croatian Academy of Sciences and Arts, published an original scientific article called “A five-year (2018-2022) study of the Eagle Owl Bubo Bubo in Croatia. The recolonization and number estimates of the Eagle Owl in lowland Croatia”. This article was authored by Biljana Ječmenica, the coordinator and initiator of the project, along with Petra Čulig, Luka Meštrović, Ivan Budinski, and Vedran Lucić. This research has shown that the Eurasian Eagle-owl is once again nesting in the lowland part of Croatia, where better legal protection and reduced persecution played an important role, and repopulation was probably possible due to strong populations in the Mediterranean part of Croatia and Slovenia. According to the results of the research, the estimated size of the population in the lowland part is 32 to 45 pairs, while it was not possible to estimate the size of the population in Primorje and Gorski Kotar due to the insufficiently researched area.

From the published research (LARUS, vol. 57, 2022.)

We would like to invite everyone interested in the monitoring of the Eurasian Eagle-owl to join us for an educational meeting, where you can learn more about the Eurasian Eagle-owl, the simple research methodology we use, and how to independently join the search for the sounds of the male Eurasian Eagle-owl.

The first educational meeting will take place on February 2, 2024, starting at 6 p.m. in Biom’s office in Zagreb (live and online; Meeting ID: 820 6854 8485); the next one will be held during mid-February in Buzet, after which we will continue with the joint monitoring of localities in the surrounding area. This way, we will cover the area of northern Istria and introduce the methodology to new volunteers through practical learning.

Of course, the invitation is extended to experienced volunteers who have already participated in the monitoring, as an additional effort will be made this year to collect data on breeding success, and experienced volunteers will be able to monitor the locations they are already familiar with.

(This article was translated into English by Maja Dragojević)