Nestling diet and fledgling production of eurasian kestrels (Falco tinnunculus) in eastern Spain.

We studied 81 Eurasian kestrel (Falco tinnunculus) nests in the Alto Palancia region (Castel16n, eastern Spain) from 1982-87. Fledgling production was recorded in routine visits to the nests, and the diet was determined by pellet analysis. The mean date of laying was 8 May (N -- 24, SD -- 11.5), similar to that of populations breeding further north in Europe. On average, each successful pair produced four fledglings per year (N = 47, SD = 0.7, range = 2-5), and no significant differences in fledging success were found among years. Grasshoppers formed the bulk of the diet during the nestling period. Mammals and birds were scarcely represented. The number of fledglings per successful pair was…