Seasonal Variation in Nestling Diet of the Great Tit Parus major in Orange Groves in Eastern Spain

Thirty-two Great Tit Tit broods were sampled using the neck-collar method. Fifty percent (n = 526) of the prey brought to the nestlings were Lepidoptera imagines (moths), almost exclusively Noctuidae. Peridroma saucia was the main moth species brought. Caterpillars were only abundant very early in the nestling stage, moths being more abundant during most of this period. We conclude that, in orange groves, the Great Tit breeding population depends heavily on moths to feed the nestlings. Fledging successs does not seem to be affected by this major change in the diet, though clutch size is smaller than in other habitats.