I copied and pasted from that link...thought it might be helpful to some. If you didn't already pay the migratory bird fee, you don't have to in order to hunt doves, but you do have to register with HIP. Read below...
Register for HIP to Hunt Doves
To hunt doves and other migratory birds in Iowa, federal regulations require that hunters be registered with the Harvest Information Program (HIP). Hunters who hunt waterfowl or other migratory birds such as woodcock register for HIP when they pay the state migratory bird fee (stamp). Although dove hunters are not required to pay the state or federal migratory bird fee they must still register for HIP to legally hunt doves. Landowners who are only going to hunt on their own land or hunters such as those 16 and under who do not need a license do not need to register for HIP.
This year, hunters who purchased their hunting licenses after August 14th should have been asked whether they were going to hunt doves. If they responded “yes” then: “Dove: Y” was printed on their license. If a hunter changes their mind or bought their license prior to August 15th they need to register with HIP to hunt doves even if they paid the state migratory bird fee.
NWBuck