A New Spring Migration Record 

For the first time during spring migration, BirdCast's live migration map showed an enormous record-breaking cross-country flight that reached more than 857 million birds on Sunday May 4^th! The fact that this number is closing in on 1 Billion Birds during a single spring migration night across the Lower 48 States is most impressive. Conditions were exceptional, with the intersection of a peak spring migration period in many areas of continental America paired with some rather intense, bird-concentrating weather. And it was all documented live and recorded on BirdCast by using the US weather surveillance radar network.

This enormous spring migration event was most pronounced above the central states, with notable concentrations in Missouri – more than 75 million birds crossed that state in particular, continuing north. The BirdCast migration tools are very helpful to birders, especially the Live Migration Maps and Local Migration Dashboard, but also the Migration Forecast Maps and Migration Alerts. To really get tuned in to migration during the peak period of May, it's worthwhile to consult any or all of the migration tools before and after a given overnight period.

You can check on migration results for individual counties or your state as a whole on the Dashboard Your Local Migration Dashboard – BirdCast, and you can check past migration results changing the date. For the Live Migration Maps you can likewise change the date in the lower right corner of the map, then click the arrow in the lower left to view overnight bird migration for any date (see Live Maps – BirdCast). And keep the link for the Migration Tools to easily to refer it at Discover Bird Migration – BirdCast

Billions of Birds: More birds migrate during fall than during spring, which is the simple result of the added numbers of fledglings produced during the summer nesting season migrating south combined with adults and subadult birds. Last fall and during the fall of 2023, BirdCast's live maps showcased the 3 biggest fall migration nights on September 25 and October 8, 2025 and October 6, 2023 – with more than a billion birds migrating south each of these amazing fall nights! To see BirdCast's original news release for the May 4 mega-migration, you can refer to BirdCast sets a new spring migration record! – BirdCast

Of course, there are local variances in migration intensity, and as an example, we share that on this historic night of spring migration, at our office location in southeast North Dakota on the night of May 4^th was less than robust. In fact, May 4^th was a poor migration event due to an incoming rain front, but it did lead to the first warbler fallout the following day. However, overnight Thursday May 7 was actually the most significant overnight migration to date at our office this spring, which led to a very impressive Friday fallout of songbirds.

Almost as impressive was the migration of Sunday May 10^th, which brought the first Baltimore Orioles of the season. However, statewide, Sunday's migration was much more significant, with BirdCast estimating more than 78,000,000 birds migrating overhead – but most of that night's migration took place above the western half of the state. So this local information emphasizes why you should check migration in your state, and especially your own county, if that's where you are birding. This local migration information was gleaned from BirdCast's Migration Dashboard at North Dakota - Night of May 10, 2026 - Migration Dashboard - BirdCast. Tonight could be another exciting night of spring bird migration!