Hierarchical cluster analysis used to detect the presence of relatively homogeneous groups of calls.

<p>Parameters used: log-transformed Duration, Median F0, Standard Deviation F0, Ampvar, NHR, Jitter and Shimmer. Coloured bar below dendrogram indicates distribution of putatively described calls. Red boxes indicate the five cluster solution (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0179337#pone.0179337.s006" target="_blank">S1 Fig</a>) determined by highest average silhouette score (0.69). Dotted blue line indicates eight cluster solution (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0179337#pone.0179337.s007" target="_blank">S2 Fig</a>) determined by Hubert and Arabie Adjusted Rand Index best matching the putative repertoire.