Wilson's Warblers are one of our remarkable signs of spring. Colorful and energetic, they're bailing on their winter territory in Southern Mexico and Central America and headed north. Many of them are already here, with many more close behind (photo by USFWS).

Check out the eBird maps below to see how they're on their way:

Here's the map for February of this year, showing a few Wilson's Warblers in California, but most still hanging out way down south:

And then here's the map for the first 20 days of this year, showing more movement northward:

But look at the map from the end of March last year, showing what's happening now:

And then April of last year: