The song of the hermit thrush, a common North American songbird, is renowned for its apparent musicality and has attracted the attention of musicians and ornithologists for more than a century.
Recent research has shown that hermit thrush songs, like much human music, use pitches that are mathematically related by simple integer ratios and follow the harmonic series. These findings add to a small but growing body of research showing that a preference for small-integer ratio intervals is not unique to humans; such findings are particularly relevant to the ongoing nature/nurture debate about whether musical predispositions such as the preference for consonant intervals are biologically or culturally driven.
This according to “Overtone-based pitch selection in hermit thrush song: Unexpected convergence with scale construction in human music” by Emily Doolittle, et al. (Proceedings of the National Academy of Sciences of the United States of America CXI/46 [18 November 2014] pp. 16616–16621).
Below, a hermit thrush video that will fascinate your cats; more recordings, including slowed-down ones, are here.