Parks or groves – Which tree stands are more important for cavity dwellers in a highly deforested agricultural landscape?

Large forest patches are essential for the protection of forest species, but in an agricultural landscape, groves or non-forest tree stands, such as rural parks, can also be refuges for many forest birds. During the research, the importance of groves and rural parks for the occurrence of cavity nesters was compared in a heavily deforested agricultural landscape (approximately 440 km²) in SE Poland. For this purpose, in 2016, the habitat requirements of four species: the Great spotted woodpecker, Syrian woodpecker, European starling, and Eurasian nuthatch were evaluated. It was assumed that the cover of tree stands, isolated tree stand patches surrounded by treeless and built-up habitats, and also the quality of tree stands, e.g. the presence of trees with large trunk dimensions and trees with poor health condition or the number of trees in tree habitats, may play an important role for the presence of the studied species. The research has shown that rural parks could be more important for the protection of cavity nesting birds because these tree stands were inhabited by the studied species twice as often as the groves. A positive impact on the occurrence of cavity nesters had a larger tree cover area, as well as the presence of trees with large trunk dimensions. Isolation with tree-less habitats or built-up areas has no negative impact on the occurrence of cavity nesters. Research indicates that when planning the protection of cavity nesters in agricultural landscapes, rural parks should also be taken into account, as they are valuable refugia for this ecological group of birds and may also play an important role in the protection of biodiversity in heavily deforested agricultural landscapes.