Installation of artificial nests to enhance the populations of the Barn owl in Lemnos

Installation of artificial nests to enhance the populations of the Barn owl in Lemnos

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March saw the completion of another successful action in the framework of the “Conserving and enhancing agricultural biodiversity on Lemnos” project co-funded by the A.G. Leventis Foundation and implemented by MedINA.

Following the creation of a Valonia oak nursery in cooperation with the Special Vocational Education School of Repanidi in Lemnos, the next step was the protection and enhancement of the population of the Barn owl (Tyto alba) through the installation of artificial nests. The Barn owl is known as the farmers’ best ally as it naturally controls the population of rodents.

A barn owl (Tyto alba) in Atsiki in Lemnos! © Athina Kavaleri / MedINA.

In Lemnos, the presence of the Barn Owl is confirmed in the literature and by MedINA’s first-hand scientific research on the island through the Terra Lemnia, project while interviews with members of the local community have also played an important role. However, as noted by Assistant Professor of the Department of Biology of Patras, Mr. George Mitsainas, whose research team has studied the species’ feeding habits on Lemnos, “the increase in tourist pressure on the island is reducing the available nesting sites on Lemnos as many derelict buildings are undergoing restoration”.

To strengthen the species’ populations, MedINA, in collaboration with the Association for Management and Conservation of Biodiversity in Agricultural Ecosystems – “TYTO”, installed six artificial nests in four carefully selected villages of Lemnos, in cooperation and communication with members of the local community (Map 1).

Map 1. The four areas where artificial nests for the Barn owl were installed in the framework of the project “Conserving and enhancing agricultural biodiversity on Lemnos”.

According to the international literature, artificial nests are one of the best management measures to enhance Tyto alba populations. In fact, it seems that the species over natural sites sometimes prefer artificial nests! [1].

Soon, the MedINA team will be back in Lemnos to monitor the success of nest occupancy! Hopefully, we will soon have the first successful breeding of the species in our nests!

What do we know about the Barn owl?

In Greece, Tyto alba has been recorded and reproduced both on the mainland and the islands. It is a farmland bird most commonly found near cultivated land or grasslands, where scattered trees also occur.

Possessing long, broad wings that allow it to twist and turn sharply, the Barn owl is a keen predator, although it relies more on hearing than sight! The species specializes in hunting on the ground and its main food source is small mammals.

Characteristically, after eating its prey, it excretes through vomit (pellets) all that it cannot digest, mainly skulls and bones, thus allowing a thorough analysis of its feeding ecology. When researchers locate a nest, the pellets are collected and analyzed in the laboratory, using a stereoscope and identification keys based on the characteristics of the skulls (extra hint: the morphology of the skull, and of its features such as the morphology of the jaw, are distinguishing features of mammals).

In our country, the dietary habits of the species are well studied, with studies available for both the mainland (Thessaly, Evros, Lake Ismarida, Attica) and the islands of Greece (Kythira, Astypalaea, Kos, Evia, etc.). Its main prey species are mainly Rodents (mice, rats) but also Eulipotyphla (shrews, moles) [2, 3, 4].

This makes the Barn owl one of the most economically valuable wildlife animals for agriculture, as its contribution to rodent control is highly effective and much better for the environment than the use of rodenticides. In integrated rural management projects, the use of rodenticides to control harmful species has been replaced by the installation of artificial nests which is a less costly method [5].


We thank Nikos Katakozinos and Tassos Kothalis from the village of Kamnia, Athina Kavaleri from Atsiki, Nikos Kostakis from Kontopouli, as well as the local councillor of the village of Sardon for their collaboration during the fieldwork. Special thanks also to the craftsman Panagiotis Bolimos for his dedication during the construction of the nests.


  1. Meyrom K., Motro Y., Leshem Y. Aviel S. Izhaki I. Argyle F.; Charter M. 2009. Nest-Box use by the Barn Owl Tyto alba in a Biological Pest Control Program in the Beit She’an Valley, Israel. Ardea. 97 (4): 463–467. DOI:10.5253/078.097.0410.
  2. Bontzorlos V., Peris S., Vlachos C., Bakaloudis D. 2005. The diet of Barn Owl in the Aagricultural landscapes of central Greece. Folia Zoologica, 54(1–2):99–110.
  3. Kiamos Ν., Lymberakis P., Rallis G. & Poulakakis N. 2019. Barn Owl (Tyto alba) prey in Evros (Greece) and the discovery of a new mammal for the Greek fauna, Journal of Natural History, 53:27-28, 1691-1705, DOI: 10.1080/00222933.2019.1658820.
  4. Barberi A., Smyriliou-Zerva M., Karetta X., Iliopoulos G., Mitsainas G. 2021. First results from the recording of the micro-mammal fauna of Lemnos through the analysis of Tyto alba pellets. Proceedings of the 10th Conference of the Hellenic Ecological Society, October 14-17, 2021, Ioannina.
  5. Paz A., Jareño D., Arroyo L., Viñuela J., Arroyo B., Mougeot F., Luque-Larena J. J., Fargallo J. A. 2013. Avian predators as a biological control system of common vole (Microtus arvalis) populations in north-western Spain: experimental set-up and preliminary results. Pest Management Science. 69 (3): 444–450. DOI:10.1002/ps.3289.