Winter’s frost has given way to a quick warm spell on this March day in Humboldt Park. With it comes noise: Nearly a hundred birds trill out around the park’s centerpiece lagoon, their black bodies chasing each other in a diffuse cloud as the sun peeks above rooftops. 

When one of the birds finally rests, flashes of red and yellow are revealed on its wings. It’s still the slog of winter for these red-winged blackbirds  – all males, who migrate well in advance of their female counterparts to partake in territorial scuffles. The lagoon’s soon-to-be overgrown reed bed makes a perfect nesting spot, but it’s far from the only area that Milwaukeeans share with this often-misunderstood breed. The bird is a “love it or hate it” species – you may find its aggressive disposition charming or pesky, its conk-la-ree song beautiful or incessant.

Tree branches are dark with common grackles and European starlings, while an assortment of waterfowl hunts out of waters teeming with panfish stocked by the DNR. With the arrival of their female partners, red-winged blackbirds retreat into the growing cattails.

Some, like the American robin, deem the park safe enough to raise a family, and they collect newly shed fur, branches, leaves and candy wrappers to weave together into nests. Rains provide worms, warmer temps the promise of insects. The muddy conditions are perfect for a handful of swallow species, whose erratic ballet and shimmering bodies entrance a viewer.  

Some birds come in all shapes and sizes. Not the rare and fleeting warblers. Every one of the over 30 species found in Wisconsin are about the same size: tiny. But what these palm-sized birds lack in size, they make up for in charisma. Their colors and patterns are eclectic, their songs constant and cheery. The most common warbler of Humboldt Park, the yellow-rumped warbler, moves at what feels like a mile a minute. It’ll eventually settle with a mate in Canada’s conifer forests but spends a few weeks every year in Milwaukee, kicking off birdwatchers’ local warbler season.  

Spring in Wisconsin is far from an even progression from winter to summer; Humboldt Park’s feathered visitors know that well. After a few balmy days abruptly end with traditional winter temperatures, a belted kingfisher pauses its hunting of carp and bluegill as snow begins to fall. Downy woodpeckers  seek out tree cavities for warmth while migrants fight with sparrows for scraps from birdfeeders.

Every year, we human Wisconsinites shrug off these rapid weather fluctuations, but they are an increasing global challenge for avian migrators. Birds have changed their migration patterns due to climate change, leaving their wintering grounds sooner than they did 50 years ago. For birds passing through wonky Wisconsin, the risk of hitting a “false spring” is increasingly common for migrants that aren’t built for cold weather. Cold snaps result in deaths both direct and indirect, as frost can have long-lasting impacts on staples of the food web, like bugs and fruit. For birds that do survive, limited resources can weaken their ability to reproduce and defend hatchlings.  

As temperatures level out, a final wave of migrants arrives, usually around mid-May. Common yellowthroat and Nashville warblers are mainstays in the forests of northern Wisconsin, so the mid-May sightings at the lily pond in Humboldt Park’s southeast corner represent a final pit stop before the pocket-sized birds reach their nesting grounds up north. 

As turtles bask in the sun, eagle-eyed viewers catch the most fleeting of sights: a female ruby-throated hummingbird  harvesting spider webbing for her nest. These perennial crowd-pleasers don’t frequent Humboldt Park – there are no nectar-dispensing bird feeders here, though there are plenty across the city.  

Eventually, the amber reeds turn emerald again and the lagoon bids its migrants a safe travel north. Some will return in the fall and winter, but those layovers will be just as succinct. 

A few feet off the beaten path, a mother mallard guides her newborn chicks to the shoreline, their yellow tufts sticking out even in the dense brush. Some of them are curious about the human giants around them, others cautious. Cars stop to let the much larger Canada goose goslings cross. 

Above, a bird of prehistoric grandeur lands on a branch jutting out from a small island. Of all the park’s wild visitors, the great blue heron might be the most cherished. While nobody knows if it’s the same heron that returns year after year, one always shows up, dubbed “Blue” by its human admirers. Great blue heron remains have been found in the Great Plains dating back 14 million years, and its lengthy ancestry shows in how the bird carries itself: its S-like neck curvature, that thick, pointed beak. 

Nearby, cars speed down busy streets carrying their occupants to work, but in the lagoon this predator hunts in virtual stillness – a patience and poise that’s often rewarded with a full stomach. There’s more than one way to make a living in this city.  

New Life for the Lagoon? 

The Humboldt Park lagoon faces a threat that may seem commonplace to passersby. Cattails destroy the lagoon’s ecosystem by starving native plant life and turning its bottom to sludge. To combat this, Humboldt Park Friends has proposed a full restoration of the lagoon, with a wish list potentially including a partial or full dredge, installation of a pump to circulate water and replacement of cattails with native plants. The plan comes with a hefty price tag – as high as six or even seven figures, long-term. Fundraising will begin later this year. It’s a continuation of stewardship by the park friends group that has included the #100ForHumboldt tree-planting initiative after disease and infestation devastated tree populations, and annual park cleanup days. Last May’s event was its largest yet, as volunteers of all ages armed themselves with grabbers, buckets and gloves to remove litter from the park’s 73 acres.

Human activity is a major problem for migrating birds; only 30% of songbird hatchlings and 50% of adults survive migration each year. Birds are easily disoriented and thrown off course by light pollution, a threat that can be mitigated by turning off unnecessary illumination during spring and fall migrations. And high-rise buildings are like minefields in the sky for birds, though casualties can be decreased by building with bird-safe glass that has a pattern or lesser transparency that deters bird strikes.

Kyle Lloyd Arpke is a freelance filmmaker, photojournalist and naturalist who lives in South Milwaukee.