During the nestling period in 1968, the composition of the Lesser Spotted Eagle's food was investigated at nine eyries in the Carpathians in Eastern Slovakia. Considerable differences were apparent before (see Table 1) and after (see Table 2) 10 July, which were attributed to changes in the height of the vegetation following the harvest. The above-average incidence of the brown hare in the first period is explained by the fact that the L. S. E. had had to fall back on this otherwise unusual prey because the population cycle of the common vole - the bird's basic diet - was at its lowest point. The exceptionally dry, warm weather from May to July presumably prevented the L. S. E. from substituting amphibians, as was observed in low-lying land, under similar conditions, by Russian authors in the Belovezhskaya Pushcha (Byelorussia).