Fig. 3. Smoothers for partial effects of explanatory variables on total number of corpora albicantia: (A) age (n = 88) and (B) dorsal blubber thickness (n = 81) in BIOCET P. phocoena, and (C) age (n = 123) and (D) dorsal blubber thickness (n = 100) in BIOCET D. delphis. In all cases, the y axis represents the strength and direction of the effect of the explanatory variable. The axis label format indicates the estimated degrees of freedom (edf or ″curviness″) of the smoother. For example, s(Age, 2.96) indicates a smooth function of age with edf = 2.96.