What breed are my ducklings

[Brijohnson11]

I have these ducklings and I don’t know what breed they are can anyone help me? One picture is from when they were babies and the other one is from now

 

[JedJackson]

The one on the left in the pool is a crested duck. Not sure about the other one. It may be a crested duck as well, just lacking the crest, because it looks very similar to the other.