I mostly see wild turkeys dusting in the morning; but then again, I can only hunt until noon so that is when I am observing the turkeys the most. LOL! Last night I went out and sat along the field edge just to enjoy the evening show. Several turkeys were dusting around 7pm. IF the dusting behavior of chickens is anything similar, well, my chickens dust morning, noon and evening with morning and noon being slightly more popular.