Bird food plants Bird food plants Bird food plants are certain trees, shrubs and herbaceous plants bear fruits which afford food for birds. These have been discovered by observation, and by the scientific examination of the contents of birds' stomachs. By planting those species, therefore, which have been proved most desirable and that are suited to the climate and soil of the chosen location, birds can be attracted to the vicinity of dwelling houses or to any other desired spot as a copse or shrubbery, or, on the other hand, lured away from valuable orchards, since they appear to like best arid, bitter,
Birds of the Danube Delta (29); Mongolian (33); Chinese (2). The transpalearctic type contains 43 species. For Romania's latitude – delta included – the north-originating species (Arctic and Siberian) appear as winter-and passage birds, while the south-originating species (European, Mediterranean and Mongolian) are met with as sedentary and summer species. Further comments upon the manner birds migrate - namely the causes, which start on migration - and upon the way they orient themselves during migration, resulted in the hypothesis of the ""inner time"" and ""inner space"", which, along with their known senses, allow the migratory birds to perfect the migratory act in time and space.