This wetland is an important habitat for migratory birds.
Tips
memory
候 here means 'season' (as in 气候 'climate' or 时候 'time/season'), not 'to wait'. So 候鸟 = 'season bird' — a bird that follows the seasons. The opposite is 留鸟 (liúniǎo, 'stay bird'), a year-round resident species.
culture
Migratory birds are loaded with meaning in Chinese poetry — wild geese (大雁) returning south signal autumn loneliness; swallows (燕子) coming back mark spring's arrival. The phrase 候鸟式 ('migratory-bird-style') is also a modern term for snowbird retirees who winter in Hainan.