nuptial plumage

noun Ornithology.
  1. the plumage assumed by a male bird during the courtship period, especially in those species that are more colorful at this period.

Origin of nuptial plumage

First recorded in 1830–40
Also called breeding plumage.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018