I was trying to find a pic of one the closes thing I could come up with was a Chestnut Teal.
Female
Here's what the males kind of look like,
Chest's are brown actually more like a Reddish color. not brown, my mistake..
These are NOT calls but just to give you and idea of the...
What did the ad say?
It's similar to the grey or mallard call duck. It's not considered a standard breed.
Did they mention chestnut breasted call or just chestnut call??
Either way it's the way the coloring is on the chest and or back of the duck. It's kind of like the female grey but...