Cornell Lab of Ornithology dismissed the avian hypothesis. Specifically, spectrogram comparisons were made between the unknown Area X whistler(s) and Eastern Screech Owl (Megascops asio). The spectrographic signatures are notably different, with the M. asio whinny invariably appearing at around 1.5 khz on spectrograms; the Area X whistler(s) is around 2 khz (as seen on the accompanying spectrogram). One other candidate, the ringtail (Bassariscus astutus) was also reviewed because it has been doc