Geographical distribution of Redhead.    Breeding  Migration  Year-round  Nonbreeding
BirdLife International. 2016. Aythya americana. The IUCN Red List of Threatened Species 2016: e.T22680367A92859064. https://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T22680367A92859064.en. Downloaded on 29 June 2018.
Cephas