The DHARMA Initiative genetically engineered large birds called "hy-birds" to test how animals adapt to the Island's unique properties. ("[[|]]") The birds' wings span 16 feet, and their cry sounds like the name "Hurley". DVDs even subtitle one's cry as "Hurley", but Sawyer mocked Hurley for noting the resemblance. ("Live Together, Die Alone, Part 1") DHARMA kept the birds at the Hydra station, which featured large aviary cages. ("[[|]]") ("A Tale of Two Cities")