Fig. 3: Variation in UV reflectance within and among species is structured by ecology and life stage rather than by sex.
From: Ecological drivers of ultraviolet colour evolution in snakes
a Individuals within the same species with similar visible colours can vary markedly in UV reflectance, as illustrated here by two Amazonian tree boas from the same population. b Total UV reflectance varies within and among species on both the dorsal and ventral surfaces of snakes (N = 438 individuals; species means, far right). c Within species, juveniles have significantly higher dorsal reflectance than adults (F(1,394) = 10.15, p = 0.002), while males and females show no differences in dorsal UV reflectance at any life stage (N = 410 individuals; F(1,312) = 0.16, p = 0.694). Among species, arboreal and nocturnal species have significantly higher dorsal reflectance than any other ecological category (N = 438 individuals; habitat t = 1.75, p = 0.035; diel activity t = 2.05, p = 0.046). Statistical tests for sex and age: mixed-effect models with clade as a random effect. Statistical tests for habitat and diel activity: phylogenetic generalised linear models. All tests were two-tailed. See Supplementary Figs. 5–7 for further plots of sex and full ecological data. Asterisks indicate significant differences among factors. For all box plots, centre line represents data median, bounds represent ± 1.5 IQR, and whiskers represent minima and maxima excluding outliers. Source data are provided as a Source Data file.
