This work summarizes results concerning the nest development of synanthropic birds (Tree Sparrows, House Sparrows, Great Tits, Jackdaws, House Martins) in urban environments, published to date from the research done by the author and sets them against the background of data in the field under discussion. Concentration changes in Ca, Mg, Fe, Zn, Cu, Mn, Co, Cd and Pb were different with age, depending on the health status of nestlings (healthy, sick and dead) and the species. The intensity and directions of changes in the concentrations of elements in the bodies of developing nestlings were found to be dependent on the degree of chemical contamination in the environment. During development in the nest, there was a slower rise in the concentrations of physiological elements (Ca, Mg, Fe, Zn) in the organs (liver, kidneys, lung, heart, spleen, pectoral muscles, brain, feathers, and bones: femur, patella, fibula, tibiotarsus, larsometatarsus)', of nestlings from polluted environments than in those from unpolluted ones. In turn, the concentrations of non-physiological elements (Pb, Cd) showed a greater rate of increase in nestlings from polluted areas, which were also characterized by a slower increase in biomass, with maximum mass being attained just before flight from the nest. Increased Pb and Cd concentrations were associated with impaired growth of nestlings, i.e. decreased asymptote of body masses growth. Unpolluted urban areas are characterized by greater hatching and fledging successes than the polluted ones. Chlorinated hydrocarbons can affect embryonic mortality amj may be an indirect cause of nestling death. Higher concentrations of toxic heavy metals limit the laying-down of physiological elements in nestlings, which accumulate small amounts of Pb and Cd in soft tissues and greater amounts in bones and feathers. Clutch sizes are influenced not only by concentrations (in the bodies of females) of elements important for eggs production, but also by the concentrations of toxic heavy metals in females and eggs - a factor in turn dependent on the concentrations of these metals in the environment (thereby attesting to its degree of pollution). Sparrow nestlings whose lipid content was lower than that necessary to survive the night, had lower Fe concentration in the liver compared with those with higher lipid reserves. Pb and Cd have an unfavourable impact on the lipid and protein reserves of nestlings. Urban birds can exist in their polluted environments due to a variety of adaptations.
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