Five years of volunteering crowned with scientific paper on Eagle Owl

Such extensive and long-term research would not have been possible without volunteers, and without them we would not know how many pairs of Eagle Owls are there in the once abandoned area

  • 20.03.2023.

photo: Paul Cools (CC-BY-NC)

Did you know that the term “citizen science” entered the Oxford English Dictionary in 2014? The usage of the term itself began at the end of the 20th century for various scientific projects in which citizens, as amateurs who are not professionally engaged in science but only as a hobby, participated in data collection. While the term “citizen science” is not added to the Croatian dictionary yet, our volunteers collect data on a large scale and that data is being used for scientific and professional purposes. Bird watchers are one of the larger groups of citizens who regularly collect valuable data.

Biom’s volunteers participate in several citizen science projects. We are exceptionally proud of the volunteers who participate in the Eagle Owl monitoring program, for a scientific paper has just been published based on the data they collected. “A FIVE-YEAR (2018 – 2022) STUDY OF THE EAGLE OWL Bubo bubo IN CROATIA The recolonisation and number estimates of the Eagle Owl in lowland Croatia” is signed by Biljana Ječmenica, coordinator and initiator of the project, Petra Čulig, Luka Meštrović, Ivan Budinski and Vedran Lucić. The paper was published in the 57th issue of Larus, the scientific journal of the Institute of Ornithology of the Croatian Academy of Sciences and Arts.

The method is very simple

The methodology of the Eagle Owl monitoring is very simple and anyone can participate. The training is short, it’s important just to memorize the sound of the Eagle Owl and to read the monitoring instructions in order to learn everything you need about the species. In the field you just need a little patience and attentiveness. The Eagle Owl monitoring is carried out at the end of winter when they are most active and when it is possible to hear them clearly. Hearing an Eagle Owl near a suitable cliff for nesting means that it has claimed its territory. And that’s it, recording the data on the presence or absence of the Eagle Owl is all the work that the volunteers do.

photo: Darko Podravec

It seems very simple, but it is important to note that volunteers visited 154 locations 485 times over 5 years and discovered – 60 active territories of the Eagle Owl in an area that had not been researched like that before. The project of Eagle Owl monitoring in continental Croatia began with the discovery of a nesting pair in a lowland area where Eagle Owls were thought to have been extinct for some time. At the same time, LIKE – Living on the Karst Edge, the Interreg Slovenia-Croatia project, was launched in central Istria with the aim of transferring the experience from Slovenian partners of their 20-year voluntary monitoring program to our volunteers. The majority of Eagle Owls in Croatia are nesting in the coastal part of the country, while they went extinct in the lowland at the beginning of the 20th century. This research confirmed the repopulation of the lowland part of the country and it is now assumed that there are up to 45 pairs there.

Old quarry by the field – typical Eagle Owl habitat (photo: Biljana Ječmenica)

Such extensive and long-term research would not have been possible without volunteers, and without them we would not know how many pairs of Eagle Owls are there in the once abandoned area. The publication of the scientific paper is therefore also a recognition of the volunteers who selflessly participated in the project.

The monitoring of the Eagle Owl continues, with this year’s field research ending soon. The already known couples were visited by “The Guardians of the Eagle Owl”, volunteers who monitor the Eagle Owl in their locations, and the results will be known soon. You can get information about other citizen science programs at Biom at