I cant find any ducklings that look like these. they dont look exactly like mallards, could they be a cross breed? they were bought at tractor supply about 2 weeks ago. top picture is recent and bottom is when they were younger.
Magpies are notoriously difficult to breed to their breed standard. Most aren't going to look exactly like the pictures you see online. Many of the pictures you will find posted by hatcheries or breeders are going to be the best example of the breed, this goes for all breeds. So while your ducklings are totally adorable and will likely grow into beautiful ducks, they aren't likely to be at breed standard. Unless you plan on showing them or starting your our breeding program it doesn't really matter.