Evolution
- Evolution of enlarged body size of coal tits Parus ater in geographic isolation from two larger competitors, the crested tit Parus cristatus and the willow tit Parus montanus, on six Scandinavian islands
Summary: On six widely separated Scandinavian islands, an enlarged food base and intraspecific competition has caused the coal tit Parus ater to evolve morphologically in the direction of two absent competitors.