astaxanthin banded beak bird black-wingtips brilliant-scarlet-coloration captive carotenoid colorful colors colourful colours distinctive eudocimus-ruber exotic-bird feathers forager ibis large-toed long-legged long-narrow-decurved-bill long-necked mangrove-tree-nesting plumage prolific red-pigmentation scarlet-ibis South-American species tail threskiornithidae-family tropical wader water-bird wings