Whistlers

noun

1. Someone or something that whistles, or who plays a whistle as a musical instrument.
2. Any of several passerine birds of the genus Pachycephala, of Australasia and the western Pacific.
3. Any bird that whistles or is noted for its whistling vocalisations (applied regionally to various specific species).
4. The goldeneye (certain ducks of genus Bucephala).
5. The whistling marmot (Marmota caligata).