A paper has been published about analysis of niches occupied by two species of Spotted Eagles and their hybrids. Authors evaluated habitat and trophic niches in two hybridizing birds of pray, the declining Greater Spotted Eagle Clanga clanga (mainly living wetlands) and the more numerous Lesser Spotted Eagle Clanga pomarina (preferring mosaic farmlands). 24 Spotted Eagles, including hybrids, were tracked with GPS receivers to estimate the home‐range size, land use composition and landscape structure in co-existing populations. In addition to information for landscape utilization, data for diet composition were evaluated. Home‐ranges of the two species were similar in size and open foraging habitats consisted mostly of agricultural landscape. However, landscape utilization of the Greater Spotted Eagle was largely driven by the composition of land‐use types, whereas the Lesser Spotted Eagle was mostly influenced by structural components of the landscape. Voles were a main part of the diet in both species but other prey classes were different. Hybrids exhibited intermediate or mixed features for home‐ranges and diets. Results provided evidence for reduced niche partitioning and competition between both Spotted Eagles, which may have been reinforced by anthropogenic habitat alteration.
Vali, U., Abel, U., Nellis, R., Sein, G., Sellis, U., & Mirski, P. (2022). Weak niche partitioning between closely related sympatric Greater (Clanga clanga) and Lesser Spotted Eagles (C. pomarina). IBIS. https://doi.org/10.1111/ibi.13088