What Pattern?

[BlueTheBrahma]

That isn’t mottling, it’s part of the juvenile patterning

These are my duckwing welsummers at a similar age, see how almost all the white mottling has disappeared.

This is a speckled Sussex chick I found, a mottled variety.

I don’t have much experience with duckwing chicks other than welsummers, so if it varies I apologise, but I don’t believe a chick this age would have mottling if it wasn’t mottled.