Another note. When coming back from Minnesota one year, 3 of us drove home while my uncles and cousins flew back. We had our 3 limits of Walleye and about 350 Perch (At the time, the limit on Perch was 100). We were taking back fish for my uncles also. And, we had one of my uncle's licenses with us thinking that was acceptable. It was not.
They had a roadblock in Hackensack Minnesota and the DNR was pulling over all fishermen to check for violations. Luckily for us, we only had our (3) limits of Walleye. The Minnesota DNR really only seemed interested in the Walleye and didn't care too much about the Perch. He said we were in violation with the Perch. Carrying another person's licese was not good enough. But, he just gave us a verbal and sent us on our way.
I've never heard the keeping it separate rule. As far as fish goes that is. Possession of ducks or geese is about the only thing I've ever heard about keeping harvests separate. Or if upland hunting, just making sure you're not carrying over your limit is acceptable. I don't think the DNR cares who's bird it is.
But it doesn't surprise me that the DNR is unclear on this one. Half of the Illinois DNR's R&R's are "subject to the CPO's interpretation"...