bird-watcher

n [C], `bird-watching n [U] (person whose hobby is) studying birds in their natural surroundings （在大自然中）对鸟的研究（的爱好者）.

biomedical, bionic, bionics, biopsy, biorhythm, bioscope, biotechnology, bipartisan, bipartite, biped, biplane, birch, bird, bird of paradise, bird of passage, bird of prey, bird sanctuary, bird-bath, bird-song, bird-table, birdbrained, birdcage wire, birdie, birdlime (also lime), birds, birdseed, biretta, Birmingham, birth, birth certificate, birth rate, birth-control, birthday, birthmark, birthplace, birthrate, birthright, biscuit, bisexual, bisexuality,