Смогоржевский, Л.А.; Коткова, Л.И.
(Вестник зоологии, 1973)
When studying the nestlings nutrition Hirundo rustica L. (25 tests), Delichon urbica L. (54 tests), Motacilla alba L. (33 tests) and Muscicapa striata (P a I I.) (44 tests), 23, 59, 19, 38 species or groups of food objects ...