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Fig. 9 | BMC Zoology

Fig. 9

From: Species-level divergences in multiple functional traits between the two endemic subspecies of Blue Chaffinches Fringilla teydea in Canary Islands

Fig. 9

Global Silhouette Index values for different clustering solutions produced by the k-medoids clustering algorithm applied to songs of polatzeki and teydea. The GSI has a value greater than 0 when data are clustered more than expected by chance. Higher values represent a greater clustering tendency. The GSI tends to produce higher values with smaller values of k, so we corrected the GSI by comparing its output with simulated data-sets. The peak with k = 2 corresponds to the division of songs between polatzeki and teydea

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