Complex sentence: Some semi-aquatic birds use terrestrial locomotion, surface swimming, underwater swimming and flying (e.g. ducks, swans); diving birds additionally use diving locomotion (e.g. dippers, aulks).
Split into simpler sentences: Some semi-aquatic birds use terrestrial locomotion, surface swimming, underwater swimming and flying (e.g., ducks, swans). Diving birds also use diving locomotion (e.g., dippers, aulks).