Date published:

Litter in birds’ of prey nests - study of two kite species

Zduniak P., Bocheński M., Maciorowski G. 2021. How littered are birds’ of prey nests? Study of two sympatric species. Science of the Total Environment 790: 148079;

DOI:  10.1016/j.scitotenv.2021.148079

People produce a huge number of different products that become waste over time. Only some of them decompose quickly or are recycled. However, most of them, especially when they are plastic products, accumulate in the environment, affecting the organisms that occur there. This problem is clearly visible and discussed in marine environments. It is significantly less noticeable in terrestrial habitats, where the spatial dispersion of litter makes it difficult to assess the degree of pollution and its impact on the ecosystems.

In the publication of Dr. Piotr Zduniak from the Department of Bird Biology and Ecology of the Adam Mickiewicz University, Dr. Marcin Bocheński from the University of Zielona Góra and Dr. Grzegorz Maciorowski from the University of Life Sciences in Poznań the problem of terrestrial environment pollution based on the analysis of the presence of anthropogenic waste in the nests of two species of raptors - the Red Kite and the Black Kite was presented. Both species, like most birds of prey, are rare components of terrestrial ecosystems. Since they occupy the top positions in their trophic chains, they are considered good indicators of environmental quality.

The study showed the presence of anthropogenic debris in all examined nests of both species. The average number of litter items per nest was 31, and their maximum number was 66. The average total area of litter  per nest was 0.44 m2, and total area of litter in the most polluted nest was 0.83 m2. Taking into account the fact that the average surface area of the studied nest was 0.45 m2, the obtained values should be considered as very high. Moreover, as much as 71% of identified litter (65% of its total area) was plastic waste.

The results of the conducted study show that there is a lot of litter in the breeding habitats of both species of kites and that they are readily available to them. Although birds are recognized as indicators of environmental quality, knowledge about the impact of environmental pollution on their populations is still limited. Therefore, the authors point out the need for further research on anthropogenic waste in the birds’ nests, especially apex-predators. This allow for a better understanding of the functioning of ecosystems under strong anthropogenic pressure, which results in the progressive degradation of the environment and its pollution.