A Quantitative Test of the Predicted Relationship between Countershading and Lighting Environment

@article{Allen2012AQT,
  title={A Quantitative Test of the Predicted Relationship between Countershading and Lighting Environment},
  author={William L. Allen and Roland J. Baddeley and Innes C. Cuthill and Nicholas E. Scott-Samuel},
  journal={The American Naturalist},
  year={2012},
  volume={180},
  pages={762 - 776}
}
Countershading, a vertical luminance gradient from a dark back to a light belly, is perhaps the most common coloration phenotype in the animal kingdom. Why? We investigated whether countershading functions as self-shadow concealment (SSC) in ruminants. We calculated “optimal” countershading for SSC by measuring illumination falling onto a model ruminant as a function of time of day and lighting environment. Calibrated images of 114 species of ruminant were compared to the countershading model… 
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