Thirteen people with binoculars standing on lawn in front of brick building

words by Mikko Jimenez

Climbing the Humboldt Park Boathouse stairs to meet the 13 others joining the August 31 walk, I noticed some of the surrounding trees were just starting to change color. Summertime in Chicago is ending and, for birders, that means fall migration is starting up.

Our first birds of the day were spotted from the boathouse terrace: a pair of Double-crested Cormorants, which, as our leader, Chris Holden, explained, were sunning to dry their wings. The island in the northwest corner of the lagoon, where they rested, would prove to be productive habitat as we circled it and viewed from different vantage points.

Small yellow bird with black wings and tail, black cap, and thick orange bill, perched on a stem next to a yellow flower. — American Goldfinch. *Photo by Anney Grish, Humboldt Park, Aug. 31, 2025.*

Chris led us across a bridge into the garden, where a male American Goldfinch worked the tall vegetation. From there, we got a better view of the cormorants and closer inspection revealed a Black-crowned Night Heron concealed in the trees behind them. As we left the garden, a Northern Cardinal sang late into the season and a Gray Catbird mewed, showing off its rusty undertail coverts.

Moving north, we saw a mixed flock working the trees behind the fishing dock. As Chris explained the concept of niche partitioning, whereby species differentiate their resource use to forage together, we identified a Black-and-white Warbler, Wilson’s Warbler, and Chestnut-sided Warbler. The vegetation was dense with much of the activity in the canopy, so it’s possible we left some passerine identifications on the table, but we decided to move on.

Black duck with white splotched on neck, pale white eye ring, and light-colored bill, sitting in the water. — Mystery duck, likely a Mallard or Muscovy Duck hybrid. *Photo by Chris Holden, Humboldt Park,* *Aug. 31, 2025.*

On the north end of the lagoon, we scanned for unusual waterfowl among the Canada Geese, Wood Ducks, and Mallards. We picked out a large, dark duck with a light bill, eye rings, and tiny wings. We didn’t confirm an ID, but the consensus was that it may have been a domestic Mallard or Muscovy Duck, potentially with some hybridization.

Rounding the corner, we caught a glimpse of a raptor soaring above the island. We got a clear look at its white head and tail to confirm: an adult Bald Eagle! Chris was visibly excited, noting it was one of a handful of sightings for this species at Humboldt Park. Nearby, we spotted a high-flying Osprey and a perched Red-tailed Hawk. We also saw a pair of Warbling Vireos foraging on the island, a species we heard vocalizing throughout our walk.

We crossed Humboldt Drive to the west section and spotted a Black-crowned Night Heron and Green Heron through the thick reeds. Moving south, we saw Barn Swallows flying over the beach and resting on the fieldhouse. We also had our first American Robin and Northern Flicker flyovers. As we neared the bridge in the southwestern corner of the park, a Downy Woodpecker tapped on a snag and a Great Blue Heron caught fish, rounding out a heron trifecta! We ended at the Jens Jensen Formal Garden, where we caught a quick glimpse of an American Kestrel before it flew off.

Twelve people with binoculars peering up into the sky, standing on grass in front of trees.

Back at the Boathouse, we recapped and celebrated our highlights. There was some discontentment with our seemingly short species list of 25. But. earlier in the walk, Chris said something to the effect of “If birding was only rarities, it would take some of the fun out of it.” I think this sums up late-summer/early-fall birding—getting excited for migration to ramp up while enjoying the early arrivals in the meantime.

To me, this walk captured that, and we had a great group to share it with.

Field Trip Recap: Sunday Social at Humboldt Park