Carel discovered a fascinating website about iris pigmentation. As Carel notes:
Morgan Worthy, a retired psychologist, has put together an iris pigmentation site that includes lists of iris color for over 5,600 vertebrate species, along with observations based on his database that range from the insightful to the mundane to the crackpottish.
There are hypotheses there concerning eye color in humans and in animal predators. Looks like a treasure trove of material for blogging when you are out of inspiration and especially if you are wondering what to send next for the Skeptic's Circle.
Having problems commenting? (UPDATED)