We had a pretty big spread in the middle of a big timber hole for the last 3 days of the season, and I was amused at how accurately wood ducks would buzz in and land with the 3 or 4 woodie decoys we had out.
Not to say that they won't come in to an all-mallard spread, but it confirmed with me how they actually look at them and discern the differences.
I like having a little bit of variety to the spread to help match the birds in the area. Plus, we need to do our part to support the duck decoy industry. :tu: