Below is a map from the Arkansas Game and Fish Commission's website that I frequently look at leading up to, and during our duck season here in Tennessee and Arkansas. As explained in the text, this is not an indication of mallard numbers, only their migration progression. I will update this map as it is updated on agfc.com.
Every week from late September to early February, more than 100 experts in North America's central flyway rank the progress of mallard migration in their areas. We compile their data to bring you a map showing the status of the mallard migration.
These rankings do not depict mallard abundance. They indicate the relative progression of the fall migration. Estimated peak numbers of mallards may be lower or higher than average numbers during previous years due to annual variations in local wetland and environmental conditions. As a result, a dark color does not necessarily mean that lots of mallards are present in that region
These maps depict real-time estimates of migration. Revised maps will be posted in February. Some variation in results may also occur depending on the number of experts reporting for a given week.
The mallard migration observation network was established as part of a broader project to use GPS satellite telemetry to better understand mallard movements, distribution, and habitat use. The rankings provided by participants this fall will be compared with the locations of mallards marked with GPS satellite telemetry units to help determine if mallards carrying the additional weight of a transmitter display normal migration behavior.