beak bird blue crest display elaborate feather green head male ornamental Pavo cristatus peacock plumage pride proud background beautiful beauty elegance elegant eye eyes feathers luxurious luxury natural nature opulence opulent rich texture afterfeather barbicels barbs barbules branched branches bright calamus color coloration colored colorful colors colour coloured colourful colours complex integumentary appendage coverts distinctive elongated-coverts epidermal-growth extravagant eye-spotted tail feather’s-eye flying-bird interlocking barbules iridescence iridescent outer-covering pavo peafowl pen phasianidae plume rachis shaft tail vane