Field trip report: Harms Woods

 
Tiny bird in profile facing left, with a long, thin, slightly curved beak, round dark eye, white from bill through underbelly, greenish-brown on head, back and wings, wings back in flight, approaching purple flowers.

Ruby-throated Hummingbird. Photo by Dustin Weidner, Chicago Botanical Gardens, Sept. 23, 2022.

words by Lauren Kostas

The calendar was saying fall, but the weather was shouting summer when Vinod Babu led a group of seasoned and novice birders—including one new friend who was on her second day of watching and identifying birds—to Harms Woods. The trip started with the story of the bold Ruby-throated Hummingbird. Vinod explained that many of these tiny neotropical migrants take a treacherous route to wintering grounds in Central America. Rather than hugging the coastline, they choose to fly over the Gulf of Mexico. That’s a daunting 20-hour non-stop flight over 500 miles of water.

Contemplating the hummingbird’s journey, we began our own considerably shorter trip along the North Branch of the Chicago River. Throughout our trip, we discussed native plants, varied bird behaviors and how habitat provides a vital clue on what birds to expect or hope for in a particular space. We spotted 26 species that morning.

One of our first sights was a Scarlet Tanager, a highlight of the trip. The bird sported the olive plumage that is noted in its scientific name—Piranga olivacea. Tanagers are experts at dining on bees and wasps, whacking a bug against a branch and rubbing it against the bark to remove a stinger.

Other species we saw included a migrating Yellow-bellied Sapsucker and local woodpeckers of the Downy, Hairy and Red-bellied varieties. A Ruby-crowned Kinglet, Red-breasted Nuthatch, Brown Creeper, Hermit Thrush, and group of Yellow-rumped Warblers hanging out in a bush over the river were among the other birds we spotted. A Winter Wren, popping in and around a pile of deadwood, also caught our eyes.

large raptor in profile, head turned to face the camera, perching on a branch with green leaves behind. The sharply hooked bill and round eyes are yellow. The head and back feathers are scalloped brown with light edges and the breast is pale red.

Cooper’s Hawk. Photo by Madhu Nukathoti, Harms Woods, Oct. 4, 2025.

We concluded our trip with a fun identification exercise. Was it a Sharp-shinned or a Cooper’s Hawk that perched overhead? Size (the Cooper’s is generally bigger, but females are usually bigger than males in both species, complicating things), head shape (“Sharpies” have small, rounded heads while Cooper’s have blockier heads), and tail (with Cooper’s having rounded tails) all provide clues. In the end, after looking at the photos, Vinod was inclined to believe we saw a Cooper’s Hawk: “The head seems angular, and the bird seems to have a dark grey cap rather than a hood extending past its nape.”

Overall, it was a great morning of sharing stories, spotting cools birds, snapping photos and enjoying the great resource that is the Cook County Forest Preserves.

 
Field TripKris HansenHarms Woods