Nesting site of eagles

The painting “A nesting site of eagles” was performed by the artist A. N. Komarov for the section “Evidence of evolution” on the subject “Problem of a species in terms of the variability of hunting birds.” The work illustrated age-specific changes in birds, according to A. F. Kots: “For a long time, eagles with white tails and dark plumage and those with dark tails and rusty plumage were treated as various species and referred to, respectively, as “berkut” and “kholzan” (both translated as “golden eagle”). However, continuous monitoring of the birds at nesting sites showed that they are in fact the same species, young birds having white tails and older ones having darker tails, meaning that every “kholzan” used to be a “berkut”…