“…Following AV classification, classification and regression tree (CART) and random forest (RF) analyses were run with the 16 extracted variables (Table 1) to assess classification to broad classes and to call types. CART and RF analyses have emerged as preferred methods for supervised classification in humpback whale repertoire studies (Fournet et al, 2018b(Fournet et al, , 2018cGarland et al, 2012;Rekdahl et al, 2013Rekdahl et al, , 2017. These methods are preferred because they are minimally affected by outliers, nonnormality, nonindependent data, correlated variables, and sample size (Armitage & Ober, 2010;Breiman, 2001;Breiman et al, 1984), all of which are common in humpback whale repertoire studies.…”