Duck Migration Map and Report: How to Read One

Yes, for the ten states DuckCast covers: North Dakota, Arkansas, Missouri, South Dakota, Nebraska, Kansas, Mississippi, Louisiana, Oklahoma and Texas. The map colors each of the 90 regions by its current migration score, rebuilt through the day from live weather, the freeze line upstream, crop progress and hunter reports, and each morning the radar check marks whether birds actually moved over the region after dark. It is not a national map and it does not pretend to be: states the forecast does not model are not painted.

It depends on the question you are asking. If you want to know what hunters saw yesterday, a report-based map with a dense network in your area is hard to beat. If you want to know whether a migration happened over you last night regardless of who was out, radar is the only instrument that watched. If you want to know whether to burn a vacation day on Thursday, you need a forecast, and you should hold it to account against something that observes. DuckCast is built as the third kind with the second kind bolted on: a regional forecast, checked every night against NEXRAD radar, with hunter reports feeding the score at the region level. We do not claim it is the best map for every question, only that it is the one that shows its work.

A report is the written version of the same information: what moved, where, and what the next few days look like. On DuckCast the report is the score itself, a 0 to 10 number for each region with the eight weighted factors behind it, last night's radar verdict, the 48-hour outlook and the freeze line. Every covered state has a page listing its regions, and every region has a page describing what the forecast watches there. Your state wildlife agency also publishes official survey counts and reports during the season, and those remain the reference for anything regulatory.

DuckCast scores by species where the timing genuinely differs. The map can be switched between mallard, pintail, gadwall, wigeon, green-winged teal, snow goose, each with its own season curve in every state, and the state's default species is the one its hunters actually open on rather than mallard everywhere. Louisiana opens on gadwall, and Texas and Mississippi open on green-winged teal, because the federal harvest survey shows hunters in all three take more of those birds than mallards. Blue-winged teal is the one common duck not modelled: it is gone from every covered state before the regular seasons open, and the September teal guide covers it instead.

Weather and the score refresh through the day from hourly conditions at every region center and every upstream weather station. The radar check runs on five scans a night per region, decoded from raw NEXRAD Level II volumes, and posts its verdict for the morning. Crop harvest updates weekly in season from USDA figures, and hunter reports appear as they are filed. Nothing on the map is hand-drawn or updated on a human schedule.

Not from DuckCast, and we would rather say that than paint a state we have not built. Each state gets its own regions, its own upstream stations, its own radar sites and season and crop curves fitted to it, which is real work that does not copy and paste. The vote on the home page decides which state is built next, and the nationwide season-dates guide covers every state's dates in the meantime.