In the fascinating world of birds, there exist examples where egg coverings take on a unique hue – pink. This phenomenon has long been a conundrum to scientists, with various theories proposed to account for this https://docs.google.com/spreadsheets/d/1qL-aIM5KxaBFeWx9uqNsFK4KthW88k7ORDu_7a02O8s/edit?usp=sharing