Why does The Scarlet Ibis fade to pink if in captivity?

The Scarlet Ibis fades to pink in captivity primarily due to a lack of access to their natural diet, which is rich in carotenoid pigments found in the crustaceans and other food sources they consume in the wild. In captivity, if their diet lacks these pigments, their feathers lose their vibrant red coloration and can become more muted. This change is a result of the birds’ inability to synthesize the necessary pigments for maintaining their bright plumage. Thus, diet plays a crucial role in their coloration.