
(from the article `anseriform`) ...male generally deserts her and joins forces with other males, often after making a molt-migration to another area some distance from the breeding ... ...the plumage of the male characteristically showing more brilliance and pattern than that of the female. Feathers are normally lost and replaced at ......
Found on
http://www.britannica.com/eb/a-z/e/8

A post breeding plumage that occurs in some species; often refers to plumage that male ducks have between their breeding plumage and their non-breeding plumage; some species of ducks are unable to fly during this plumage.
Found on
http://www.encyclo.co.uk/local/22214

Plumage worn briefly by male waterfowl just after mating or after the breeding season; more muted than the plumage worn through most of the year and sometimes resembling that of the female.
Found on
http://www.encyclo.co.uk/local/22218

The set of dull-colored feathers worn briefly after the breeding season by some adult birds, such as ducks. In eclipse plumage, male ducks look like females, which do not change much in appearance. Eclipse plumage is acquired by a complete molt after the breeding season, and is soon replaced through a partial molt that produces the brighter colors ...
Found on
https://academy.allaboutbirds.org/bird-academys-a-to-z-glossary-of-bird-ter

New dull plumage after breeding season, especially in ducks
Found on
https://birds.iitk.ac.in/glossary?page=61

Short-lived, drab non-breeding plumage acquired by some if sunbirds and ducks.
Found on
https://www.encyclo.co.uk/local/22222
No exact match found.