Birds Through the Year

The calendar

Wisconsin’s bird year runs on a predictable order. Spring migration begins at the end of January and builds to a peak around mid-May ¹; nesting fills June and July; fall migration runs from August into November; winter brings a smaller set of hardy visitors from the north. The order stays the same each year, while the exact dates slide with each spring’s weather.

Spring arrivals

• Sandhill cranes start showing up in mid-February, and their rattling calls over a still-frozen marsh are the first real sign of spring ¹.
• Robins head north in early March; some spend the whole winter in southern Wisconsin eating berries ¹.
• Ducks and geese are among the earliest migrants ², piling onto the first open water as the ice goes out.
• May: the peak, when the woods fill with warblers, vireos, orioles, tanagers, flycatchers, and hummingbirds, sometimes dozens of species on a single morning walk.

The Gulf crossing

Many of the birds that arrive in May have just done something remarkable. Ruby-throated hummingbirds, scarlet tanagers, and indigo buntings cross the Gulf of Mexico in spring, roughly 600 miles nonstop ². A hummingbird weighing about as much as a penny flies through the night over open water. They land in Texas or Louisiana hungry and depleted, then work north through stopover woods and wetlands to Wisconsin, which is why protecting the habitat in between matters as much as protecting nesting grounds.

Summer nesters

From 2015 to 2019, more than 2,000 volunteers surveyed thousands of 3-by-3-mile blocks for the Wisconsin Breeding Bird Atlas II and confirmed 226 species nesting in the state, 13 of them new since the first atlas in 2000, including a Glossy Ibis at Horicon Marsh ³. Breeding birds range from common loons on northern lakes to grassland birds like bobolinks in hayfields, so the date you mow a hayfield matters to them.

Comebacks

Some of Wisconsin’s most visible birds were rare within living memory:

• Sandhill cranes were hard to find until the last 30 to 40 years; now they’re statewide, a true recovery story ¹.
• American white pelicans, one of North America’s largest birds, have come back strongly and pass through in flocks of hundreds ¹.
• Bluebirds became far more common over the last 20 years, largely because people put up nest boxes for them ¹.

Fall and winter

Fall migration is slower and more spread out. Shorebirds start moving in July and August, warblers drift south in September in duller fall plumage, and waterfowl and cranes stage in big flocks before freeze-up. In winter, the birds at a Wisconsin feeder are the year-round residents (chickadees, nuthatches, cardinals, woodpeckers, blue jays) plus visitors from farther north, like juncos and, in some years, redpolls and other finches.

What to take from this

Migration starts in late January, cranes return from mid-February, robins and ducks come in March, and the peak is mid-May, when many songbirds have just crossed the Gulf of Mexico nonstop. The second breeding bird atlas confirmed 226 nesting species. Cranes, pelicans, and bluebirds are comeback stories. Learn the order of arrivals and you’ll know what to look for in any week of the year.