My Cayugas had a lil yellow on their chests that faded as they got older. It depends on how much yellow. If it's just a tinge, I'd say Cayuga. If bright yellow, I'd vote Swedish. All duck breeds can have crests. Too cute!
Here is a more recent picture the yellow pretty much faded so I think they maybe cayugas and they also are getting feathers on their wings and they are that green blackish color but I noticed black Swedish do as well so I'm confused
YES! Cayuga. If it was swedish, the yellow would have become white. Cayugas are the sweetest. The one with the crest was my daughters baby until a raccoon got the beauty. Enjoy!