Sexual dichromatism in the fur of a bat: An exploration of color differences and potential signaling functions

Sex differences in body color (i.e., sexual dichromatism) are rare in bats and, more broadly, in mammals. The eastern red bat (Lasiurus borealis) is a common tree-roosting bat that occupies much of North America and has long been described as sexually dichromatic. However, previous research on this species found that absolute body size and collection year were better predictors of fur color in preserved specimens than sex. We revisited this issue and photographed 82 live eastern red bats under standardized conditions, then used image analysis to quantify pelage hue, saturation, and value. We used an information theoretic approach to evaluate four competing hypotheses about the principal drivers of color differences in the fur of eastern red bats. Our analyses demonstrated that sex was a better predictor of pelage color than body size; males had redder, more saturated, and lighter pelages than females. Additionally, fur color of juvenile vs. adult bats differed somewhat as juveniles were..., Bat Capture
We followed the guidelines of the American Society of Mammalogists for the use of wild mammals in research (Sikes et al. 2019), institutional animal care and use protocols (University of Illinois Urbana-Champaign, #21022), and all white-nose syndrome decontamination recommendations (White-nose Syndrome Disease Management Working Group 2020). We held appropriate Indiana and USFWS permits.
Photography
We performed all photography in the field. We held each bat in a standardized position (wings closed, forearms held against body and uropatagium spread, with bats’ ventral surface down) and photographed them in a portable LED-lit photo studio box (EMART International Inc., Westminster, CA, USA) using a digital single-lens reflex camera (EOS Rebel T6) with an EFS 18-55 mm lens (Canon, Tokyo, Japan). To achieve homogeneous lighting conditions, we did not use flash to photograph bats but relied only on the illumination produced by the two LED strips within the photo studio box. We p..., , # Sexual dichromatism in the fur of a bat: An exploration of color differences and potential signaling functions

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Data that support the results outlined in our manuscript, titled \"Sexual dichromatism in the fur of a bat: An exploration of color differences and potential signaling functions.\" For information on how the data were collected, please refer to the manuscript.

## Description of the Data and file structure

Dataset is stored in csv format and contains the following headers:

image_id: unique id associated with each representative image
age: age of bat, adult or juvenile
sex: sex of bat, female or male
repro: reproductive condition of bat, pregnant, lactating, post-lactating, nonreproductive, or scrotal
mass: mass of bat (xx.x) in grams
fal: forearm length of bat (xx.x) in mm
area_uro: pixels housed within the selected area of the uropatagium
hue_uro: mean hue score across selected area of the uropatagium
saturation_uro: mean saturation score across selected area of the ur...