Fig. 2
From: Evolution of contact and alarm calls in the Kenyan endemic Hinde’s babbler (Aves: Passeriformes)
Variance – covariance principal component analyses of contact (a, c) and alarm (b, d) calls identified significant (both one-way PERMANOVA: P < 0.001) differences of call characteristics from all individuals (irrespective of family membership) recorded along Nzeeu River (blue points), Kalundu River (red) and Ithani River (black) (a, b), and among single bird families recorded along these rivers (c, d: family colours are given in Table 3); PCA = here Principal Component Axis