Ten-plus years ago, someone named Henry Griffin announced on a bird-watching forum that he’d be leading bird walks near his home in Oak Park. As a longtime bird watcher (now simply “birder”), I was intrigued. I joined the first of those walks. Imagine my surprise to find that Henry was a recently minted teen. My amazement increased when, very early in the walk, he looked up to the sky at a tiny dot flying by and identified it. My thought? Nonsense. He didn’t even use binoculars. But I did. And he was right. He birded with a camera! Only!
Henry led his local walks through his high school years, as well as many outings at Miller Meadow, Columbus Park and Thatcher Woods. He drew a substantial and loyal following because he is extraordinarily talented, but most of all he’s personable and a fine young teacher.
Henry went off to college. When he was ready to leave, he got me to pull together the walks for the fall migration season, using a combination of my contacts and his list of walkers. He would lead a few of the season’s walks, but as Henry became more deeply involved in his studies and his music (he’s a marvelous musician, an operatic baritone and pianist), more of the arranging fell to me.
Our group has grown to over 90 members, from 5 to 15 participants on any given walk. Henry still leads a few walks during each season. We mutter among ourselves that birds that don’t show up when we’re birding on our own seem to be there for Henry, but it’s not magic: he has extraordinary eyesight, hearing and a superb memory for things he’s seen and heard.
With Henry away, two experienced birders took over leading our walks. Ed O’Brien has been birding since he was a teenager and has traveled extensively to see birds. Lisa Spellman is, like Henry, an excellent bird photographer. She takes dozens of photos on the walks she leads and confirms what we think we have seen, sometimes even capturing images of birds we didn’t know we saw.
When we go birding as a group, we use the Cornell University Lab of Ornithology digital tools, particularly the eBird and BirdCast apps. As we walk, we employ eBird to record each species and how many of each species the group sees. While several walkers do their own recording, two of us act as quasi-official recorders for the group.
One purpose of this effort is to track one’s own “life list” of birds. The main purpose, though, is to participate in a remarkable citizen science project that keeps track of species frequency and numbers over time. Millions of birders across the world submit their sightings, some on a daily basis.
The other application we use is BirdCast. This is a free tool developed in a partnership between Cornell, Colorado State University and University of Massachusetts Amherst. The facility provides live nightly migration maps and numbers of birds overflying particular areas, usually broken down into counties across the U.S. The maps can be viewed as animations that show the flow of birds during a night’s flight from approximately sundown to sunrise.
From its large eBird database of information gathered over several years, BirdCast predicts what migratory birds to expect at any given time during a migration season. The nightly information can be used to anticipate what birds might be present on a walk, as well as the likelihood of seeing them at all.
Astounding numbers
BirdCast tracks migration from March 1 to June 15 and from Aug. 1 to Nov. 15. In Cook County, the numbers are astounding. A few nights during a season will see 8-10 million birds flying over. Our current fall season has seen about 80 million birds flying and can expect a final number between 90 and 100 million.
This total reflects our presence in the middle of the Mississippi Flyway, one of four avian migratory flyways recognized by the U.S Fish & Wildlife Service. Our flyway path extends from Ontario, Saskatchewan and Manitoba in Canada through Michigan, Wisconsin, Illinois and Minnesota, to Alabama and Arkansas, and then to Central and South America.
In the spring of 2024, our group identified 88 species of birds. We won’t know what we’ve seen this fall until the season is over. The songbirds most represented in our sightings are passerines, i.e. birds that perch, and the most diverse passerines are in the “New World Wood Warbler” family that contains 120 species. The warblers present special challenges because they are small birds most of which flit quickly from branch to branch high up in trees, seeking insects to eat. Because they change plumage from spring to fall, many species become drab and quite similar to each other. This is one reason our experienced leaders are so helpful.
We also see various hunting birds, multiple types of hawks and the occasional eagle or owl, as well as Chimney Swifts and Nighthawks, which spend hours flying with beaks agape, catching innumerable airborne insects. We catch views of water birds of many types, including herons, ducks, geese, and cormorants. By the time the great favorite of birders and non-birders alike, the Sandhill Cranes, fly over in their great flocks toward the end of the year, we have long since finished our Oak Park Migration Bird Walks season.
We have gotten used to the cycle of arrivals in the spring and the congruent cycle of departure in the fall, helped along by BirdCast’s anticipated species through segments of the migration. This does not diminish our excitement each season. The hunter that remains in all of us finds expression in this endeavor, though the objective is not to bring them back to the cave to eat. Rather, it is to experience wonder on a regular basis and to hope for something we’ve never seen before.
It happens every year.
Ed McDevitt is a River Forest resident.