There have been times I have tagged waterfowl-when I was crossing the border, when I was at a friends island with several others hunting for a couple of days, when taking to a picker. The one I have to be careful is of transporting without a head attached. Me and my friends have cabin we hunt out of, and I like to clean my ducks before I go home. I really like to filet them out with the skin attached, and keeping a wing or the head on is a challenge. I can relate a story about somebody cleaning a duck at their camp here in south jersey to cook it in the kitchen at the camp, having a federal game warden come by, check him out, give him a ticket for transporting a bird without a wing or head(he wasn't in his vehicle). He went to court (Federal) and the warden didn't show up, so it was dismissed.
Here are the federal tagging requirements. Some stuff is pretty clear. Some of the stories related are a stretch of storage(or the other requirements), like walking away from a blind looking for a duck and leaving the ones you bagged in your blind, or boat, or wherever you are set up with your gear. If you were ever to go to court on that, it's going to be up to the person adjudicating the matter as to how they see it and if you were guilty of something, but I personally would never worry about it because it is not a common sense argument that you have left it for storage. Separation of your ducks is something else. If there is a pile of ducks between two people(and I have dealt with this) and a game warden, I just promptly identify the ducks that I have shot. Since there were several fully plumed gwt drakes in this incident, I was questioned on how I knew this, and I said I remembered. End of discussion. Sometimes you just have to be practical if you weren't doing anything wrong.
Tagging requirement No person shall put or leave any migratory game birds at anyplace (other than at his personal abode), or in the custody of another person for picking,cleaning, processing, shipping, transportation, or storage (including temporary storage),or for the purpose of having taxidermy services performed, unless such birds have a tag attached, signed by the hunter, stating his address, the total number and species of birds,and the date such birds were killed. Migratory game birds being transported in any vehicle as the personal baggage of the possessor shall not be considered as being in storage or temporary storage.
Custody of birds of another No person shall receive or have in custody any migratory game birds belonging to another person unless such birds are properly tagged.
Termination of possession Subject to all other requirements of this part, the possession of birds taken by any hunter shall be deemed to have ceased when such birds have been delivered by him to another person as a gift; or have been delivered by him to a post office, a common carrier, or a migratory bird preservation facility and consigned for transport by the Postal Service or a common carrier to some person other than the hunter.
Gift of migratory game birds No person may receive, possess, or give to another, any freshly killed migratory game birds as a gift, except at the personal abodes of the donor or donee, unless such birds have a tag attached, signed by the hunter who took the birds,stating such hunter's address, the total number and species of birds and the date such birds were taken.
Transportation of birds of another No person shall transport migratory game birds belonging to another person unless such birds are properly tagged.
Species identification requirement No person shall transport within the United States any migratory game birds, except doves and band-tailed pigeons, unless the head or one fully feathered wing remains attached to each such bird at all times while being transported from the place where taken until they have arrived at the personal abode of the possessor or a migratory bird preservation facility.
Marking package or container No person shall transport by the Postal Service or a common carrier migratory game birds unless the package or container in which such birds are transported has the name and address of the shipper and the consignee and an accurate statement of the numbers of each species of birds therein contained clearly and conspicuously marked on the outside thereof.
