ИСТИНА

Dietary carotenoids play important role both in visual signaling and in physiology of birds as pigments, antioxidants, and immune-stimulants. Carotenoid concentration in Lepidoptera was shown to be richest in comparison to other invertebrate in the diet of insectivorous birds (Eeva et al. 2010). As rule, caterpillar abundance varies markedly during long reproductive season. Basing on data on the seasonal dynamics of caterpillar biomass in forest habitats at Zvenigorod biological station (Moscow region), we compared carotenoid concentration in yellow ventral feathers of Great Tit nestlings from first and second broods, and from different natural habitats within the same breeding cycle. Diet composition of each brood was evaluated using video recording of their nest boxes. Carotenoid concentration in feathers was measured by Ramon spectroscopy. Results on asymmetry in concentrations of carotenoids in feathers of nestlings from broods of different types are discussed.