Research into children's ideas showed that children's interpretations of natural phenomena often differ from those of scientists. The aim of our study was to identify children's ideas of various age classes (7/8-14/15) about birds. A questionnaire with 31 multiple choice and open ended questions and eight photographs were administered to 495 children from 10 elementary schools in Slovakia. Children's ideas were examined in six dimensions (bird classification, food, senses, communication, migration and breeding including parental care). We found several misconceptions, some of them with both anthropomorphical and teleological reasoning of the children about birds within each dimension. In general, misconceptions were more frequently found in younger children, but several misconceptions were similarly distributed across all age classes. (Contains 3 figures and 1 table.)