Figure 3.

Relationship between Key Variables in Pre- and Postcopulatory Male Strategies across Howler Monkey Species

Regression plots showing (A) log₁₀ mean male hyoid volume versus mean number of males, (B) mean testes volume versus mean number of males per species, (C) log₁₀ mean male hyoid volume versus mean testes volume, and (D) log₁₀ mean male hyoid volume versus ΔF. Each point represents the mean value for a distinct howler monkey species: Alouatta macconnellii (orange), A. belzebul (black), A. sara (pink), A. guariba (red), A. seniculus (purple), A. caraya (dark blue), A. palliata (yellow), and A. pigra (light blue). The slopes and intercepts of the regression lines of the linear model and PGLS model were identical in all cases, so only one line is visible in each figure. Mean values ±SE are shown. Sample sizes are given in Table S1. See also Figure S2 and Tables S1 and S2.