The harmonic scales of the hermit thrush

From The Proceedings of the National Academy of Sciences: "An analysis of song recordings of 14 hermit thrush birds reveals that most songs contain musical scales that are based on small-integer frequency ratios found in the same harmonic series commonly employed in human musical scales, and that the frequency selection does not arise from biological constraints, suggesting that scale determination is not unique to humans and may be at least partially culturally determined, according to a study."