DOI: 10.5061/dryad.0vt4b8h4p
title: Rodents show darker and redder coloration in warm and rainy environments

description: Aim: Gloger’s rule predicts that warmer and wetter areas favor more
 pigmented animals. Yet, the original formulation lacks differentiation
 between the two primary pigments: eu- and pheomelanin. We examined
 geographic variation in eumelanin and pheomelanin to unravel how various
 ecological factors influence pigment deposition, and to assess support for
 the complex version of Gloger’s rule. Location: South America. Time
 period: Contemporary. Major Taxa Studied: Sigmodontine rodents. Methods:
 We extracted pelage color data from 231 species and quantified the
 variation in eu- and pheomelanin deposition at the assemblage level. We
 performed linear multiple regression to investigate the influence of
 temperature, precipitation, predator diversity, and UVA-B radiance in
 eumelanin (lightness) and pheomelanin (redness). Results: Our findings
 support the original formulations of Gloger’s rule. Rodents in warmer and
 rainier regions, which also entails greater exposure to UV radiation and a
 diverse range of predators, exhibit darker-colored pelage. In addition,
 redder rodents prevail in warmer environments. However, contrary to the
 rule predictions, we observe a reversal for reddish patterns in relation
 to precipitation, with rainier regions showcasing more intense red
 rodents. Main conclusions: Our study breaks new ground by investigating
 previously unexplored facets of Gloger's rule in a continental
 mammalian group. We discovered compelling evidence that darker and redder
 coloration align closely with temperature and rainfall gradients. Although
 we found support for eumelanin-pelage predictions, expectations for
 pheomelanin pigmentation were only partially met. Our results might
 suggest that selective pressures act differently on dark and reddish
 coloration, revealing that coloration patterns in response to climate are
 more intricate than previously formulated.
description: This release
 encompasses both the code and data that underpin the conclusions as
 outlined in the paper. Elaborated methods can be found within the main
 body of the corresponding article.
description: This provided data and code are essential for reproducing the
 results detailed in the article. The materials are organized into specific
 folders, each serving a primary role in the analyses. The README file
 offers a succinct overview of the data structure within each
 folder.
description: # Rodents in warm and rainy regions exhibit darker and redder coloration
 This release encompasses both the code and data that underpin the
 conclusions as outlined in the paper. Elaborated methods can be found
 within the main body of the corresponding article. ## Description of the
 data and file structure The materials are organized into distinct folders
 according to their primary roles within the analyses. A concise outline of
 the data structure within each folder is presented below (in bold). ###
 *Color\_assembly\_data* folder *Lightness_space.csv*: Data on average
 lightness values in South American grid cells, determined by co-occurring
 species within each cell. Matrix columns: 'ID' (grid cell
 identification), 'RGB_mean' (average lightness from RGB species
 values), 'CIE_l_mean' (CIELAB colorspace lightness),
 'HSV_v_mean' (HSV colorspace lightness). *Redness_space.csv*:
 Data on average redness values in South American grid cells, determined by
 co-occurring species within each cell. Matrix columns: 'ID'
 (grid cell identification), 'Redness_mean' (average redness).
 ### *Color\_species\_data* folder *Species_lightness.csv*: Species-level
 pelage lightness obtained by averaging values from sampled specimens.
 Matrix columns: 'Species' (species name), 'Pic_num'
 (photos per species sampled), 'RGB_mean' and 'RGB_sd'
 (mean and standard deviation of species lightness in RGB, respectively),
 'CIE_l_mean' and 'CIE_l_sd' (mean and standard
 deviation of species lightness in CIELAB colorspace, respectively),
 'HSV_v_mean' and 'HSV_v_sd' (mean and standard
 deviation of species lightness in HSV colorspace, respectively).
 *Species_redness.csv*: Species-level pelage redness obtained by averaging
 values from sampled specimens. Matrix columns: 'Species'
 (species name), 'Pic_num' (photos per species sampled),
 'Redness_mean' and 'Redness_sd' (mean and standard
 deviation of species redness, respectively). ###
 *Combined\_datasets\_space* folder *Combined_datasets.csv*: Dataset
 containing both response variables (lightness and redness) and predictor
 variables (temperature, precipitation, predator diversity, and UVA-B
 radiance) for each grid cell. Matrix columns: 'ID' (grid cell
 identification), 'long' (cell longitude), 'lat' (cell
 latitude), 'RGB_mean' (average lightness from RGB species
 values), 'CIE_l_mean' (CIELAB colorspace lightness),
 'HSV_v_mean' (HSV colorspace lightness),
 'Redness_mean' (average redness), 'bio1' (annual mean
 temperature), 'bio12' (annual mean precipitation),
 'UVB_UVA' (UVA/B radiance), 'Accip_rich'
 (Accipitriformes species richness), 'Carnivora_rich' (Carnivora
 species richness), 'Falc_rich' (Falconiformes species richness),
 'Strig_rich' (Strigiformes species richness),
 'Vip_rich' (Viperidae species richness). *Data_units.txt*: Text
 annotator describing the units of the used variables. ### *Shapefiles*
 folder *color_space.*: Shapefile for mapping lightness and redness
 coloration across South America, with extensions including
 '.dbf', '.prj', '.shp', '.shx'.
 *south_america.*: Shapefile of South American borders for visualization
 purposes, with extensions including '.dbf', '.prj',
 '.shp', '.shx', '.avl', '.xml' ###
 *Statistical\_analyses\_codes* folder 'Statistical_analyses.R':
 R script encompassing the procedures for primary statistical analyses and
 figure reproduction as described in the main text.