TY - JOUR
T1 - The influence of environmental and physiological factors on variation in American toad (Anaxyrus americanus) dorsal coloration
AU - Mack, Mariah
AU - Beaty, Lynne
N1 - Funding Information:
We express our sincere thanks to S. Hall, S. Nutile, A. Simpson, N. Waddell-Rutter, B. Peyton, and M. Leasure for their help with visual surveys. All research procedures were approved by the Pennsylvania State University Institutional Animal Care and Usage Committee before the start of data collection (PROTO201900727). Toad surveys and capture were performed under Pennsylvania Fish & Boat Commission collector permit 2019-01-0111.
Publisher Copyright:
Copyright © 2021 Society for the Study of Amphibians and Reptiles
PY - 2021/6/1
Y1 - 2021/6/1
N2 - Adaptive coloration in amphibians is widespread and aids in camouflage, communication, and thermoregulation. Understanding the environmental factors that contribute to color variation is important for predicting how changes in climate and habitat parameters may alter amphibian fitness. Studies on toad coloration have focused on genetic elements, dorsal spot patterns, and juveniles, but less is known about the relationship between adult toad coloration and environmental conditions. The goal of this study was to examine dorsal color variation in adult American Toads (Anaxyrus americanus) in Erie County, Pennsylvania, USA, to determine how environmental and morphological factors influence coloration. We conducted visual surveys to sample adult toads across a habitat gradient and recorded several potential predictor variables (i.e., site elevation, substrate type, snout-vent length, and body surface temperature). We calibrated photographs of each toad and quantified red (R), green (G), and blue (B) color values within seven dorsal body regions. We summarized RGB values for each dorsal body region using a principal component analysis and used model selection approaches to select between models containing different predictor variables. The most supported model to explain the variation in color of all dorsal body regions contained only site elevation. On average, the body regions of all toads from higher elevation sites were darker than those of toads from lower elevations, but the amount of variation in dorsal coloration accounted for by elevation was low. Our results suggest that the factors that drive variation in toad dorsal coloration are complex, but that this trait is potentially sensitive to environmental changes.
AB - Adaptive coloration in amphibians is widespread and aids in camouflage, communication, and thermoregulation. Understanding the environmental factors that contribute to color variation is important for predicting how changes in climate and habitat parameters may alter amphibian fitness. Studies on toad coloration have focused on genetic elements, dorsal spot patterns, and juveniles, but less is known about the relationship between adult toad coloration and environmental conditions. The goal of this study was to examine dorsal color variation in adult American Toads (Anaxyrus americanus) in Erie County, Pennsylvania, USA, to determine how environmental and morphological factors influence coloration. We conducted visual surveys to sample adult toads across a habitat gradient and recorded several potential predictor variables (i.e., site elevation, substrate type, snout-vent length, and body surface temperature). We calibrated photographs of each toad and quantified red (R), green (G), and blue (B) color values within seven dorsal body regions. We summarized RGB values for each dorsal body region using a principal component analysis and used model selection approaches to select between models containing different predictor variables. The most supported model to explain the variation in color of all dorsal body regions contained only site elevation. On average, the body regions of all toads from higher elevation sites were darker than those of toads from lower elevations, but the amount of variation in dorsal coloration accounted for by elevation was low. Our results suggest that the factors that drive variation in toad dorsal coloration are complex, but that this trait is potentially sensitive to environmental changes.
UR - http://www.scopus.com/inward/record.url?scp=85107917271&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85107917271&partnerID=8YFLogxK
U2 - 10.1670/20-093
DO - 10.1670/20-093
M3 - Article
AN - SCOPUS:85107917271
SN - 0022-1511
VL - 55
SP - 119
EP - 126
JO - Journal of Herpetology
JF - Journal of Herpetology
IS - 2
ER -