Research ArticleEVOLUTIONARY BIOLOGY

Nasalization by Nasalis larvatus: Larger noses audiovisually advertise conspecifics in proboscis monkeys

See allHide authors and affiliations

Science Advances  21 Feb 2018:
Vol. 4, no. 2, eaaq0250
DOI: 10.1126/sciadv.aaq0250
  • Fig. 1 Facial and vocal characteristics in a proboscis monkey male.

    Examples of (A) a male proboscis monkey face, (B) nasal/facial areas, and (C) sound spectrogram of long calls. For (B), the areas shaded by light green and dark blue are facial and nasal areas, respectively. For (C), two sequential vocalizations were included (sounds are available online), and the arrows represent the positions of the three formant frequencies.

  • Fig. 2 Significant correlations between body mass, facial characteristics, testicular volume, vocalizations, and number of harem females in proboscis monkeys.

    Bivariate plots representing the correlations between (A) the cube roots of the body mass and the square roots of the nose-to-face (N/F) ratios and (B) the testis sizes of the 18 wild males. Blue lines and shaded areas represent the linear regressions estimated by the “lm” method in R for the observed samples and their 95% confidence interval ranges, respectively. (C) Plots of the number of females belonging to eight harem groups, with the N/F ratios of the core males in the group (circles). The triangle represents the N/F ratio of one male of an all-male group (see main text for a detailed description). (D) Plots representing the correlations between the cube roots of the body mass and the square roots of the N/F ratios of the six captive males. (E) Box plot of the formant dispersion parameters (Dfs) with the body masses of six captive males. (F) Box plot of F3/F1 parameters with the N/F ratios of seven captive males. Box plots represent the medians (horizontal bold lines), 25th and 75th percentiles (bottom and top of the box), and the 1.5× interquartile ranges (whiskers). All observed data were plotted with jitter effects on the x axis.

Supplementary Materials

  • Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/4/2/eaaq0250/DC1

    table S1. AIC(c) selection of the linear models accounting for the N/F ratios using the “lm” and “degrade” functions in the “MuMIn” packages of R.

    table S2. List of subject information.

    table S3. AIC(c) comparisons of the GLMMs accounting for Dfs with and without body mass, using the “lmer,” “lme4,” and “degrade” functions in the “MuMIn” packages of R.

    table S4. AIC(c) comparisons of the GLMMs accounting for the F3/F1 ratios with and without the N/F ratios using the “lmer,” “lme4,” and “degrade” functions in the “MuMIn” packages of R.

    fig. S1. Photographs of captive monkeys.

  • Supplementary Materials

    This PDF file includes:

    • table S1. AIC(c) selection of the linear models accounting for the N/F ratios using the “lm” and “degrade” functions in the “MuMIn” packages of R.
    • table S2. List of subject information.
    • table S3. AIC(c) comparisons of the GLMMs accounting for Dfs with and without body mass, using the “lmer,” “lme4,” and “degrade” functions in the “MuMIn” packages of R.
    • table S4. AIC(c) comparisons of the GLMMs accounting for the F3/F1 ratios with and without the N/F ratios using the “lmer,” “lme4,” and “degrade” functions in the “MuMIn” packages of R.
    • fig. S1. Photographs of captive monkeys.

    Download PDF

    Files in this Data Supplement:

Navigate This Article