Share to Twitter Share to Linkedin Eggshell pigments and color patterns reveal a lot about where a bird nests and the sorts of evolutionary challenges it faces before it even hatches Robin’s egg blue: eggs of the American robin (Turdus migratorius). Blue-green eggshell pigments ... [+] protect the embryo from sunlight, which can be adaptive as long as light levels are low enough not to heat up the eggs. (Credit: Daniel Marquard / Creative Commons.) Daniel Marquard / Creative Commons When I was teaching ornithology, there were several questions that my students would invariably ask at some point during the academic term. One was why are robin eggs blue? Even Charles Darwin wondered about the evolutionary reasons that birds' eggshells range in color from white to dark greenish-blue. Since this is such a simple and obvious question to ponder, you'd think someone would have figured out the reason long ago. And indeed, there are a number of … [Read more...] about Why Are Robin Eggs Blue?