Figure 9.10
Scattergrams show single linear correlations for combined Atlantic and Pacific samples.
Rhymelike subphrases are most likely to occur in songs having the greatest number of
themes.Their presence is related to amount of different material,not simply to amount of
material.To give roughly equal weight to the contribution of different whales,the mean
value per song session (per whale),and not per song,is the unit of comparison.This was
necessary since some song sessions contain many songs and others contain few.This
explains the presence of intermediate values for number of themes (A).149 The Changing Songs of Humpback Whales
Fig.9.10